My UEK-derived config has 1030 files depending on pagemap.h before this
change. Afterwards, just 326 files need to be rebuilt when I touch
pagemap.h. I think blkdev.h is probably included too widely, but
untangling that dependency is harder and this solves my problem. x86
allmodconfig builds, but there may be implicit include problems on other
architectures.
Link: https://lkml.kernel.org/r/20210309195747.283796-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Dan Williams <dan.j.williams@intel.com> [nvdimm] Acked-by: Jens Axboe <axboe@kernel.dk> [block] Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: Martin K. Petersen <martin.petersen@oracle.com> [scsi] Reviewed-by: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
protected_* files have 600 permissions which prevents non-superuser from
reading them.
Container like "AWS greengrass" refuse to launch unless
protected_hardlinks and protected_symlinks are set. When containers like
these run with "userns-remap" or "--user" mapping container's root to
non-superuser on host, they fail to run due to denied read access to these
files.
As these protections are hardly a secret, and do not possess any security
risk, making them world readable.
Though above greengrass usecase needs read access to only
protected_hardlinks and protected_symlinks files, setting all other
protected_* files to 644 to keep consistency.
Link: http://lkml.kernel.org/r/20200709235115.56954-1-jpitti@cisco.com Fixes: 800179c9b8a1 ("fs: add link restrictions") Signed-off-by: Julius Hemanth Pitti <jpitti@cisco.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
And 'ino' field to /proc/<pid>/fdinfo/<FD> and
/proc/<pid>/task/<tid>/fdinfo/<FD>.
The inode numbers can be used to uniquely identify DMA buffers in user
space and avoids a dependency on /proc/<pid>/fd/* when accounting
per-process DMA buffer sizes.
Link: https://lkml.kernel.org/r/20210308170651.919148-2-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Christian König <christian.koenig@amd.com> Cc: Jann Horn <jannh@google.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Hridya Valsaraju <hridya@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Alexey Gladkov <gladkov.alexey@gmail.com> Cc: Szabolcs Nagy <szabolcs.nagy@arm.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Bernd Edlinger <bernd.edlinger@hotmail.de> Cc: Andrei Vagin <avagin@gmail.com> Cc: Helge Deller <deller@gmx.de> Cc: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
procfs: allow reading fdinfo with PTRACE_MODE_READ
Android captures per-process system memory state when certain low memory
events (e.g a foreground app kill) occur, to identify potential memory
hoggers. In order to measure how much memory a process actually consumes,
it is necessary to include the DMA buffer sizes for that process in the
memory accounting. Since the handle to DMA buffers are raw FDs, it is
important to be able to identify which processes have FD references to a
DMA buffer.
Currently, DMA buffer FDs can be accounted using /proc/<pid>/fd/* and
/proc/<pid>/fdinfo -- both are only readable by the process owner, as
follows:
1. Do a readlink on each FD.
2. If the target path begins with "/dmabuf", then the FD is a dmabuf FD.
3. stat the file to get the dmabuf inode number.
4. Read/ proc/<pid>/fdinfo/<fd>, to get the DMA buffer size.
Accessing other processes' fdinfo requires root privileges. This limits
the use of the interface to debugging environments and is not suitable for
production builds. Granting root privileges even to a system process
increases the attack surface and is highly undesirable.
Since fdinfo doesn't permit reading process memory and manipulating
process state, allow accessing fdinfo under PTRACE_MODE_READ_FSCRED.
Link: https://lkml.kernel.org/r/20210308170651.919148-1-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Suggested-by: Jann Horn <jannh@google.com> Acked-by: Christian König <christian.koenig@amd.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Alexey Gladkov <gladkov.alexey@gmail.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Bernd Edlinger <bernd.edlinger@hotmail.de> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Helge Deller <deller@gmx.de> Cc: Hridya Valsaraju <hridya@google.com> Cc: James Morris <jamorris@linux.microsoft.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Szabolcs Nagy <szabolcs.nagy@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Now that proc_ops are separate from file_operations and other operations
it easy to check all instances to have ->proc_lseek hook and remove check
in main code.
Currently the pde_is_permanent() check is being run on root multiple times
rather than on the next proc directory entry. This looks like a
copy-paste error. Fix this by replacing root with next.
Addresses-Coverity: ("Copy-paste error") Link: https://lkml.kernel.org/r/20210318122633.14222-1-colin.king@canonical.com Fixes: d919b33dafb3 ("proc: faster open/read/close with "permanent" files") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Greg Kroah-Hartman <gregkh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
syzbot's current top report is "no output from test machine" where the
userspace process failed to spawn a new test process for 300 seconds for
some reason. One of reasons which can result in this report is that an
already spawned test process was unable to terminate (e.g. trapped at an
unkillable retry loop due to some bug) after SIGKILL was sent to that
process. Therefore, reporting when a thread is failing to terminate
despite a fatal signal is pending would give us more useful information.
In the context of syzbot's testing where there are only 2 CPUs in the
target VM (which means that only small number of threads and not so much
memory) and threads get SIGKILL after 5 seconds from fork(), being unable
to reach do_exit() within 10 seconds is likely a sign of something went
wrong. Therefore, I would like to try this patch in linux-next.git for
feasibility testing whether this patch helps finding more bugs and
reproducers for such bugs, by bringing "unable to terminate threads"
reports out of "no output from test machine" reports.
Potential bad effect of this patch will be that kernel code becomes
killable without addressing the root cause of being unable to terminate,
for use of killable wait will bypass both TASK_UNINTERRUPTIBLE stall test
and SIGKILL after 5 seconds behavior, which will result in failing to
detect in real systems where SIGKILL won't be sent after 5 seconds when
something went wrong.
This version shares existing sysctl settings (e.g. check interval,
timeout, whether to panic) used for detecting TASK_UNINTERRUPTIBLE
threads. We will likely want to use different sysctl settings for
monitoring killed threads. But let's start as linux-next.git patch
without introducing new sysctl settings. We can add sysctl settings
before sending to linux.git.
Link: http://lkml.kernel.org/r/60d1d7f6-b201-3dcb-a51b-76a31bcfa919@i-love.sakura.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Liu Chuansheng <chuansheng.liu@intel.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: linux-kernel@vger.kernel.org Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
fs/buffer.c: add debug print for __getblk_gfp() stall problem
Among syzbot's unresolved hung task reports, 18 out of 65 reports contain
__getblk_gfp() line in the backtrace. Since there is a comment block that
says that __getblk_gfp() will lock up the machine if try_to_free_buffers()
attempt from grow_dev_page() is failing, let's start from checking whether
syzbot is hitting that case. This change will be removed after the bug is
fixed.
Link: http://lkml.kernel.org/r/9b9fcdda-c347-53ee-fdbb-8a7d11cf430e@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Layton <jlayton@redhat.com> Cc: <syzkaller-bugs@googlegroups.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Marco Elver [Tue, 13 Apr 2021 22:21:11 +0000 (08:21 +1000)]
kfence: zero guard page after out-of-bounds access
After an out-of-bounds accesses, zero the guard page before re-protecting
in kfence_guarded_free(). On one hand this helps make the failure mode of
subsequent out-of-bounds accesses more deterministic, but could also
prevent certain information leaks.
Link: https://lkml.kernel.org/r/20210312121653.348518-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Ira Weiny [Tue, 13 Apr 2021 22:21:06 +0000 (08:21 +1000)]
mm/highmem: Remove deprecated kmap_atomic
kmap_atomic() is being deprecated in favor of kmap_local_page().
Replace the uses of kmap_atomic() within the highmem code.
On profiling clear_huge_page() using ftrace an improvement of 62% was
observed on the below setup.
Setup:-
Below data has been collected on Qualcomm's SM7250 SoC THP enabled
(kernel v4.19.113) with only CPU-0(Cortex-A55) and CPU-7(Cortex-A76)
switched on and set to max frequency, also DDR set to perf governor.
FTRACE Data:-
Base data:-
Number of iterations: 48
Mean of allocation time: 349.5 us
std deviation: 74.5 us
v4 data:-
Number of iterations: 48
Mean of allocation time: 131 us
std deviation: 32.7 us
The following simple userspace experiment to allocate
100MB(BUF_SZ) of pages and writing to it gave us a good insight,
we observed an improvement of 42% in allocation and writing timings.
-------------------------------------------------------------
Test code snippet
-------------------------------------------------------------
clock_start();
buf = malloc(BUF_SZ); /* Allocate 100 MB of memory */
Base data:-
Number of iterations: 100
Mean of allocation time: 31831 us
std deviation: 4286 us
v4 data:-
Number of iterations: 100
Mean of allocation time: 18193 us
std deviation: 4915 us
Link: https://lkml.kernel.org/r/20210204073255.20769-2-prathu.baronia@oneplus.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Prathu Baronia <prathu.baronia@oneplus.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Ira Weiny [Tue, 13 Apr 2021 22:21:06 +0000 (08:21 +1000)]
btrfs: use memzero_page() instead of open coded kmap pattern
There are many places where kmap/memset/kunmap patterns occur.
Use the newly lifted memzero_page() to eliminate direct uses of kmap and
leverage the new core functions use of kmap_local_page().
The development of this patch was aided by the following coccinelle
script:
// <smpl>
// SPDX-License-Identifier: GPL-2.0-only
// Find kmap/memset/kunmap pattern and replace with memset*page calls
//
// NOTE: Offsets and other expressions may be more complex than what the script
// will automatically generate. Therefore a catchall rule is provided to find
// the pattern which then must be evaluated by hand.
//
// Confidence: Low
// Copyright: (C) 2021 Intel Corporation
// URL: http://coccinelle.lip6.fr/
// Comments:
// Options:
//
// Then the memset pattern
//
@ memset_rule1 @
expression page, V, L, Off;
identifier ptr;
type VP;
@@
// Remove any pointers left unused
@
depends on memset_rule1
@
identifier memset_rule1.ptr;
type VP, VP1;
@@
-VP ptr;
... when != ptr;
? VP1 ptr;
//
// Catch all
//
@ memset_rule2 @
expression page;
identifier ptr;
expression GenTo, GenSize, GenValue;
type VP;
@@
(
-VP ptr = kmap(page);
|
-ptr = kmap(page);
|
-VP ptr = kmap_atomic(page);
|
-ptr = kmap_atomic(page);
)
<+...
(
//
// Some call sites have complex expressions within the memset/memcpy
// The follow are catch alls which need to be evaluated by hand.
//
-memset(GenTo, 0, GenSize);
+memzero_pageExtra(page, GenTo, GenSize);
|
-memset(GenTo, GenValue, GenSize);
+memset_pageExtra(page, GenValue, GenTo, GenSize);
)
...+>
(
-kunmap(page);
|
-kunmap_atomic(ptr);
)
// Remove any pointers left unused
@
depends on memset_rule2
@
identifier memset_rule2.ptr;
type VP, VP1;
@@
-VP ptr;
... when != ptr;
? VP1 ptr;
// </smpl>
Link: https://lkml.kernel.org/r/20210309212137.2610186-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: David Sterba <dsterba@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Ira Weiny [Tue, 13 Apr 2021 22:21:06 +0000 (08:21 +1000)]
iov_iter: lift memzero_page() to highmem.h
Patch series "btrfs: Convert kmap/memset/kunmap to memzero_user()".
Lifting memzero_user(), convert it to kmap_local_page() and then use it in
btrfs.
This patch (of 3):
memzero_page() can replace the kmap/memset/kunmap pattern in other places
in the code. While zero_user() has the same interface it is not the same
call and its use should be limited and some of those calls may be better
converted from zero_user() to memzero_page().[1] But that is not addressed
in this series.
Zhiyuan Dai [Tue, 13 Apr 2021 22:21:05 +0000 (08:21 +1000)]
mm/zswap.c: switch from strlcpy to strscpy
strlcpy is marked as deprecated in Documentation/process/deprecated.rst,
and there is no functional difference when the caller expects truncation
(when not checking the return value). strscpy is relatively better as it
also avoids scanning the whole source string.
Link: https://lkml.kernel.org/r/1614227981-20367-1-git-send-email-daizhiyuan@phytium.com.cn Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> Cc: Seth Jennings <sjenning@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
mm/memory_hotplug: make unpopulated zones PCP structures unreachable during hot remove
zone_pcp_reset allegedly protects against a race with drain_pages using
local_irq_save but this is bogus. local_irq_save only operates on the
local CPU. If memory hotplug is running on CPU A and drain_pages is
running on CPU B, disabling IRQs on CPU A does not affect CPU B and offers
no protection.
This patch deletes IRQ disable/enable on the grounds that IRQs protect
nothing and assumes the existing hotplug paths guarantees the PCP cannot
be used after zone_pcp_enable(). That should be the case already because
all the pages have been freed and there is no page to put on the PCP
lists.
Link: https://lkml.kernel.org/r/20210412090346.GQ3697@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Enable arm64 platform to use the MHP_MEMMAP_ON_MEMORY feature.
Link: https://lkml.kernel.org/r/20210319092635.6214-6-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Enable x86_64 platform to use the MHP_MEMMAP_ON_MEMORY feature.
Link: https://lkml.kernel.org/r/20210319092635.6214-5-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Oscar Salvador [Tue, 13 Apr 2021 22:21:04 +0000 (08:21 +1000)]
mm,memory_hotplug: add kernel boot option to enable memmap_on_memory
Self stored memmap leads to a sparse memory situation which is unsuitable
for workloads that requires large contiguous memory chunks, so make this
an opt-in which needs to be explicitly enabled.
To control this, let memory_hotplug have its own memory space, as
suggested by David, so we can add memory_hotplug.memmap_on_memory
parameter.
Link: https://lkml.kernel.org/r/20210319092635.6214-4-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Oscar Salvador [Tue, 13 Apr 2021 22:21:04 +0000 (08:21 +1000)]
acpi,memhotplug: enable MHP_MEMMAP_ON_MEMORY when supported
Let the caller check whether it can pass MHP_MEMMAP_ON_MEMORY by checking
mhp_supports_memmap_on_memory(). MHP_MEMMAP_ON_MEMORY can only be set in
case ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE is enabled, the architecture
supports altmap, and the range to be added spans a single memory block.
Link: https://lkml.kernel.org/r/20210319092635.6214-3-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Oscar Salvador [Tue, 13 Apr 2021 22:21:03 +0000 (08:21 +1000)]
mm,memory_hotplug: allocate memmap from the added memory range
Patch series "Allocate memmap from hotadded memory (per device)", v5.
The primary goal of this patchset is to reduce memory overhead of the
hot-added memory (at least for SPARSEMEM_VMEMMAP memory model). The
current way we use to populate memmap (struct page array) has two main
drawbacks:
a) it consumes an additional memory until the hotadded memory itself is
onlined and
b) memmap might end up on a different numa node which is especially
true for movable_node configuration.
c) due to fragmentation we might end up populating memmap with base
pages
One way to mitigate all these issues is to simply allocate memmap array
(which is the largest memory footprint of the physical memory hotplug)
from the hot-added memory itself. SPARSEMEM_VMEMMAP memory model allows
us to map any pfn range so the memory doesn't need to be online to be
usable for the array. See patch 3 for more details. This feature is only
usable when CONFIG_SPARSEMEM_VMEMMAP is set.
[Overall design]:
Implementation wise we reuse vmem_altmap infrastructure to override the
default allocator used by vmemap_populate. memory_block structure gained
a new field called nr_vmemmap_pages. This plays well for two reasons:
1) {offline/online}_pages know the difference between start_pfn and
buddy_start_pfn, which is start_pfn + nr_vmemmap_pages. In this way
all isolation/migration operations are done to within the right range
of memory without vmemmap pages. This allows us for a much cleaner
handling.
2) In try_remove_memory, we construct a new vmemap_altmap struct with
the right information based on memory_block->nr_vmemap_pages, so we end
up calling vmem_altmap_free instead of free_pagetable when removing the
memory.
This patch (of 5):
Physical memory hotadd has to allocate a memmap (struct page array) for
the newly added memory section. Currently, alloc_pages_node() is used for
those allocations.
This has some disadvantages:
a) an existing memory is consumed for that purpose
(eg: ~2MB per 128MB memory section on x86_64)
b) if the whole node is movable then we have off-node struct pages
which has performance drawbacks.
c) It might be there are no PMD_ALIGNED chunks so memmap array gets
populated with base pages.
This can be improved when CONFIG_SPARSEMEM_VMEMMAP is enabled.
Vmemap page tables can map arbitrary memory. That means that we can
simply use the beginning of each memory section and map struct pages
there. struct pages which back the allocated space then just need to be
treated carefully.
Implementation wise we will reuse vmem_altmap infrastructure to override
the default allocator used by __populate_section_memmap. Part of the
implementation also relies on memory_block structure gaining a new field
which specifies the number of vmemmap_pages at the beginning. This comes
in handy as in {online,offline}_pages, all the isolation and migration is
being done on (buddy_start_pfn, end_pfn] range, being buddy_start_pfn =
start_pfn + nr_vmemmap_pages.
In this way, we have:
[start_pfn, buddy_start_pfn - 1] = Initialized and PageReserved
[buddy_start_pfn, end_pfn - 1] = Initialized and sent to buddy
Hot-remove:
We need to be careful when removing memory, as adding and removing
memory needs to be done with the same granularity. To check that this
assumption is not violated, we check the memory range we want to remove
and if a) any memory block has vmemmap pages and b) the range spans more
than a single memory block, we scream out loud and refuse to proceed.
If all is good and the range was using memmap on memory (aka vmemmap
pages), we construct an altmap structure so free_hugepage_table does the
right thing and calls vmem_altmap_free instead of free_pagetable.
Link: https://lkml.kernel.org/r/20210319092635.6214-1-osalvador@suse.de Link: https://lkml.kernel.org/r/20210319092635.6214-2-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:03 +0000 (08:21 +1000)]
selftests/vm: gup_test: test faulting in kernel, and verify pinnable pages
When pages are pinned they can be faulted in userland and migrated, and
they can be faulted right in kernel without migration.
In either case, the pinned pages must end-up being pinnable (not movable).
Add a new test to gup_test, to help verify that the gup/pup
(get_user_pages() / pin_user_pages()) behavior with respect to pinnable
and movable pages is reasonable and correct. Specifically, provide a way
to:
1) Verify that only "pinnable" pages are pinned. This is checked
automatically for you.
2) Verify that gup/pup performance is reasonable. This requires
comparing benchmarks between doing gup/pup on pages that have been
pre-faulted in from user space, vs. doing gup/pup on pages that are
not faulted in until gup/pup time (via FOLL_TOUCH). This decision is
controlled with the new -z command line option.
Link: https://lkml.kernel.org/r/20210215161349.246722-15-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:03 +0000 (08:21 +1000)]
selftests/vm: gup_test: fix test flag
In gup_test both gup_flags and test_flags use the same flags field. This
is broken.
Farther, in the actual gup_test.c all the passed gup_flags are erased and
unconditionally replaced with FOLL_WRITE.
Which means that test_flags are ignored, and code like this always
performs pin dump test:
155 if (gup->flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)
156 nr = pin_user_pages(addr, nr, gup->flags,
157 pages + i, NULL);
158 else
159 nr = get_user_pages(addr, nr, gup->flags,
160 pages + i, NULL);
161 break;
Add a new test_flags field, to allow raw gup_flags to work. Add a new
subcommand for DUMP_USER_PAGES_TEST to specify that pin test should be
performed.
Remove unconditional overwriting of gup_flags via FOLL_WRITE. But,
preserve the previous behaviour where FOLL_WRITE was the default flag, and
add a new option "-W" to unset FOLL_WRITE.
Refcount shows the difference between pin vs no-pin case.
Also change type of nr from int to long, as it counts number of pages.
Link: https://lkml.kernel.org/r/20210215161349.246722-14-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:03 +0000 (08:21 +1000)]
mm/gup: longterm pin migration cleanup
When pages are longterm pinned, we must migrated them out of movable zone.
The function that migrates them has a hidden loop with goto. The loop is
to retry on isolation failures, and after successful migration.
Make this code better by moving this loop to the caller.
Link: https://lkml.kernel.org/r/20210215161349.246722-13-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:02 +0000 (08:21 +1000)]
mm/gup: change index type to long as it counts pages
In __get_user_pages_locked() i counts number of pages which should be
long, as long is used in all other places to contain number of pages, and
32-bit becomes increasingly small for handling page count proportional
values.
Link: https://lkml.kernel.org/r/20210215161349.246722-12-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:02 +0000 (08:21 +1000)]
memory-hotplug.rst: add a note about ZONE_MOVABLE and page pinning
Document the special handling of page pinning when ZONE_MOVABLE present.
Link: https://lkml.kernel.org/r/20210215161349.246722-11-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:02 +0000 (08:21 +1000)]
mm/gup: migrate pinned pages out of movable zone
We should not pin pages in ZONE_MOVABLE. Currently, we do not pin only
movable CMA pages. Generalize the function that migrates CMA pages to
migrate all movable pages. Use is_pinnable_page() to check which pages
need to be migrated
Link: https://lkml.kernel.org/r/20210215161349.246722-10-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:01 +0000 (08:21 +1000)]
mm/gup: do not migrate zero page
On some platforms ZERO_PAGE(0) might end-up in a movable zone. Do not
migrate zero page in gup during longterm pinning as migration of zero page
is not allowed.
For example, in x86 QEMU with 16G of memory and kernelcore=5G parameter, I
see the following:
On x86, empty_zero_page is declared in .bss and depending on the loader
may end up in different physical locations during boots.
Also, move is_zero_pfn() my_zero_pfn() functions under CONFIG_MMU, because
zero_pfn that they are using is declared in memory.c which is compiled
with CONFIG_MMU.
Link: https://lkml.kernel.org/r/20210215161349.246722-9-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:01 +0000 (08:21 +1000)]
mm: honor PF_MEMALLOC_PIN for all movable pages
PF_MEMALLOC_PIN is only honored for CMA pages, extend this flag to work
for any allocations from ZONE_MOVABLE by removing __GFP_MOVABLE from
gfp_mask when this flag is passed in the current context.
Add is_pinnable_page() to return true if page is in a pinnable page. A
pinnable page is not in ZONE_MOVABLE and not of MIGRATE_CMA type.
Link: https://lkml.kernel.org/r/20210215161349.246722-8-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:01 +0000 (08:21 +1000)]
mm: apply per-task gfp constraints in fast path
Function current_gfp_context() is called after fast path. However, soon
we will add more constraints which will also limit zones based on context.
Move this call into fast path, and apply the correct constraints for all
allocations.
Also update .reclaim_idx based on value returned by current_gfp_context()
because it soon will modify the allowed zones.
Note:
With this patch we will do one extra current->flags load during fast path,
but we already load current->flags in fast-path:
Later, when we add the zone constrain logic to current_gfp_context() we
will be able to remove current->flags load from current_alloc_flags, and
therefore return fast-path to the current performance level.
Link: https://lkml.kernel.org/r/20210215161349.246722-7-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Suggested-by: Michal Hocko <mhocko@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Mike Rapoport [Tue, 13 Apr 2021 22:21:01 +0000 (08:21 +1000)]
mm/hugeltb: fix renaming of PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN
The renaming of PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN missed one occurrence
in mm/hugetlb.c which causes build error:
CC mm/hugetlb.o
mm/hugetlb.c: In function `dequeue_huge_page_node_exact':
mm/hugetlb.c:1081:33: error: `PF_MEMALLOC_NOCMA' undeclared (first use in this function); did you mean `PF_MEMALLOC_NOFS'?
bool pin = !!(current->flags & PF_MEMALLOC_NOCMA);
^~~~~~~~~~~~~~~~~
PF_MEMALLOC_NOFS
mm/hugetlb.c:1081:33: note: each undeclared identifier is reported only once for each function it appears in
scripts/Makefile.build:273: recipe for target 'mm/hugetlb.o' failed
make[2]: *** [mm/hugetlb.o] Error 1
Link: https://lkml.kernel.org/r/20210331163816.11517-1-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:00 +0000 (08:21 +1000)]
mm cma: rename PF_MEMALLOC_NOCMA to PF_MEMALLOC_PIN
PF_MEMALLOC_NOCMA is used ot guarantee that the allocator will not return
pages that might belong to CMA region. This is currently used for long
term gup to make sure that such pins are not going to be done on any CMA
pages.
When PF_MEMALLOC_NOCMA has been introduced we haven't realized that it is
focusing on CMA pages too much and that there is larger class of pages
that need the same treatment. MOVABLE zone cannot contain any long term
pins as well so it makes sense to reuse and redefine this flag for that
usecase as well. Rename the flag to PF_MEMALLOC_PIN which defines an
allocation context which can only get pages suitable for long-term pins.
Also rename: memalloc_nocma_save()/memalloc_nocma_restore to
memalloc_pin_save()/memalloc_pin_restore() and make the new functions
common.
Link: https://lkml.kernel.org/r/20210215161349.246722-6-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:00 +0000 (08:21 +1000)]
mm/gup: check for isolation errors
It is still possible that we pin movable CMA pages if there are isolation
errors and cma_page_list stays empty when we check again.
Check for isolation errors, and return success only when there are no
isolation errors, and cma_page_list is empty after checking.
Because isolation errors are transient, we retry indefinitely.
Link: https://lkml.kernel.org/r/20210215161349.246722-5-pasha.tatashin@soleen.com Fixes: 9a4e9f3b2d73 ("mm: update get_user_pages_longterm to migrate pages allocated from CMA region") Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:00 +0000 (08:21 +1000)]
mm/gup: return an error on migration failure
When migration failure occurs, we still pin pages, which means
that we may pin CMA movable pages which should never be the case.
Instead return an error without pinning pages when migration failure
happens.
No need to retry migrating, because migrate_pages() already retries
10 times.
Link: https://lkml.kernel.org/r/20210215161349.246722-4-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:21:00 +0000 (08:21 +1000)]
mm/gup: check every subpage of a compound page during isolation
When pages are isolated in check_and_migrate_movable_pages() we skip
compound number of pages at a time. However, as Jason noted, it is not
necessary correct that pages[i] corresponds to the pages that we skipped.
This is because it is possible that the addresses in this range had
split_huge_pmd()/split_huge_pud(), and these functions do not update the
compound page metadata.
The problem can be reproduced if something like this occurs:
1. User faulted huge pages.
2. split_huge_pmd() was called for some reason
3. User has unmapped some sub-pages in the range
4. User tries to longterm pin the addresses.
The resulting pages[i] might end-up having pages which are not compound
size page aligned.
Link: https://lkml.kernel.org/r/20210215161349.246722-3-pasha.tatashin@soleen.com Fixes: aa712399c1e8 ("mm/gup: speed up check_and_migrate_cma_pages() on huge page") Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reported-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Pavel Tatashin [Tue, 13 Apr 2021 22:20:59 +0000 (08:20 +1000)]
mm/gup: don't pin migrated cma pages in movable zone
Patch series "prohibit pinning pages in ZONE_MOVABLE", v11.
When page is pinned it cannot be moved and its physical address stays
the same until pages is unpinned.
This is useful functionality to allows userland to implementation DMA
access. For example, it is used by vfio in vfio_pin_pages().
However, this functionality breaks memory hotplug/hotremove assumptions
that pages in ZONE_MOVABLE can always be migrated.
This patch series fixes this issue by forcing new allocations during
page pinning to omit ZONE_MOVABLE, and also to migrate any existing
pages from ZONE_MOVABLE during pinning.
It uses the same scheme logic that is currently used by CMA, and extends
the functionality for all allocations.
For more information read the discussion [1] about this problem.
[1] https://lore.kernel.org/lkml/CA+CK2bBffHBxjmb9jmSKacm0fJMinyt3Nhk8Nx6iudcQSj80_w@mail.gmail.com
This patch (of 14):
In order not to fragment CMA the pinned pages are migrated. However, they
are migrated to ZONE_MOVABLE, which also should not have pinned pages.
Remove __GFP_MOVABLE, so pages can be migrated to zones where pinning is
allowed.
Link: https://lkml.kernel.org/r/20210215161349.246722-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20210215161349.246722-2-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Sasha Levin <sashal@kernel.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: James Morris <jmorris@namei.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
HAVE_ARCH_TRANSPARENT_HUGEPAGE has duplicate definitions on platforms that
subscribe it. Drop these reduntant definitions and instead just select it
on applicable platforms.
Link: https://lkml.kernel.org/r/1617259448-22529-7-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc] Cc: Russell King <linux@armlinux.org.uk> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
ARCH_ENABLE_SPLIT_PMD_PTLOCKS has duplicate definitions on platforms that
subscribe it. Drop these redundant definitions and instead just select it
on applicable platforms.
Link: https://lkml.kernel.org/r/1617259448-22529-6-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Heiko Carstens <hca@linux.ibm.com> [s390] Cc: Will Deacon <will@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Andrew Morton [Tue, 13 Apr 2021 22:20:58 +0000 (08:20 +1000)]
mm-drop-redundant-arch_enable__migration-fix-fix
s/x86_64/X86_64/, per Oscar
Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Andrew Morton [Tue, 13 Apr 2021 22:20:58 +0000 (08:20 +1000)]
mm-drop-redundant-arch_enable__migration-fix
s/X86_64/X86_64/, per Oscar
Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
mm: drop redundant ARCH_ENABLE_[HUGEPAGE|THP]_MIGRATION
ARCH_ENABLE_[HUGEPAGE|THP]_MIGRATION configs have duplicate definitions on
platforms that subscribe them. Drop these reduntant definitions and
instead just select them appropriately.
Link: https://lkml.kernel.org/r/1617259448-22529-5-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Will Deacon <will@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
ARCH_ENABLE_MEMORY_[HOTPLUG|HOTREMOVE] configs have duplicate definitions
on platforms that subscribe them. Instead, just make them generic options
which can be selected on applicable platforms.
Link: https://lkml.kernel.org/r/1617259448-22529-4-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Heiko Carstens <hca@linux.ibm.com> [s390] Cc: Will Deacon <will@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
mm: generalize SYS_SUPPORTS_HUGETLBFS (rename as ARCH_SUPPORTS_HUGETLBFS)
SYS_SUPPORTS_HUGETLBFS config has duplicate definitions on platforms that
subscribe it. Instead, just make it a generic option which can be
selected on applicable platforms. Also rename it as
ARCH_SUPPORTS_HUGETLBFS instead. This reduces code duplication and makes
it cleaner.
Link: https://lkml.kernel.org/r/1617259448-22529-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> [riscv] Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
This series contains config cleanup patches which reduces code duplication
across platforms and also improves maintainability. There is no functional
change intended with this series.
This patch (of 6):
ARCH_HAS_CACHE_LINE_SIZE config has duplicate definitions on platforms
that subscribe it. Instead, just make it a generic option which can be
selected on applicable platforms. This change reduces code duplication
and makes it cleaner.
Link: https://lkml.kernel.org/r/1617259448-22529-1-git-send-email-anshuman.khandual@arm.com Link: https://lkml.kernel.org/r/1617259448-22529-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc] Cc: Will Deacon <will@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
mm/mmap.c: don't unlock VMAs in remap_file_pages()
Since this call uses MAP_FIXED, do_mmap() will munlock the necessary
range. There is also an error in the loop test expression which will
evaluate as false and the loop body has never execute.
Link: https://lkml.kernel.org/r/20210223235010.2296915-1-Liam.Howlett@Oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Saravanan D [Tue, 13 Apr 2021 22:20:56 +0000 (08:20 +1000)]
x86/mm: track linear mapping split events
To help with debugging the sluggishness caused by TLB miss/reload, we
introduce monotonic hugepage [direct mapped] split event counts since
system state: SYSTEM_RUNNING to be displayed as part of /proc/vmstat in
x86 servers
The lifetime split event information will be displayed at the bottom of
/proc/vmstat
....
swap_ra 0
swap_ra_hit 0
direct_map_level2_splits 94
direct_map_level3_splits 4
nr_unstable 0
....
One of the many lasting sources of direct hugepage splits is kernel
tracing (kprobes, tracepoints).
Note that the kernel's code segment [512 MB] points to the same physical
addresses that have been already mapped in the kernel's direct mapping
range.
Source : Documentation/x86/x86_64/mm.rst
When we enable kernel tracing, the kernel has to modify
attributes/permissions of the text segment hugepages that are direct
mapped causing them to split.
Kernel's direct mapped hugepages do not coalesce back after split and
remain in place for the remainder of the lifetime.
An instance of direct page splits when we turn on dynamic kernel tracing
....
cat /proc/vmstat | grep -i direct_map_level
direct_map_level2_splits 784
direct_map_level3_splits 12
bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @ [pid, comm] =
count(); }'
cat /proc/vmstat | grep -i
direct_map_level
direct_map_level2_splits 789
direct_map_level3_splits 12
....
Link: https://lkml.kernel.org/r/20210218235744.1040634-1-saravanand@fb.com Signed-off-by: Saravanan D <saravanand@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
mm: /proc/sys/vm/stat_refresh stop checking monotonic numa stats
All of the VM NUMA stats are event counts, incremented never decremented:
it is not very useful for vmstat_refresh() to check them throughout their
first aeon, then warn on them throughout their next.
Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2102251514110.13363@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
mm: /proc/sys/vm/stat_refresh skip checking known negative stats
vmstat_refresh() can occasionally catch nr_zone_write_pending and
nr_writeback when they are transiently negative. The reason is partly
that the interrupt which decrements them in test_clear_page_writeback()
can come in before __test_set_page_writeback() got to increment them; but
transient negatives are still seen even when that is prevented, and I am
not yet certain why (but see Roman's note below). Those stats are not
buggy, they have never been seen to drift away from 0 permanently: so just
avoid the annoyance of showing a warning on them.
Similarly avoid showing a warning on nr_free_cma: CMA users have seen that
one reported negative from /proc/sys/vm/stat_refresh too, but it does
drift away permanently: I believe that's because its incrementation and
decrementation are decided by page migratetype, but the migratetype of a
pageblock is not guaranteed to be constant.
Roman Gushchin points out:
For performance reasons, vmstat counters are incremented and decremented
using per-cpu batches. vmstat_refresh() flushes the per-cpu batches on
all CPUs, to get values as accurate as possible; but this method is not
atomic, so the resulting value is not always precise. As a consequence,
for those counters whose actual value is close to 0, a small negative
value may occasionally be reported. If the value is small and the state
is transient, it is not an indication of an error.
EINVAL was good for drawing the refresher's attention to a warning in
dmesg, but became very tiresome when running test suites scripted with
"set -e": an underflow from a bug in one feature would cause unrelated
tests much later to fail, just because their /proc/sys/vm/stat_refresh
touch failed with that error. Stop doing that.
Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2102251510410.13363@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
mm: restore node stat checking in /proc/sys/vm/stat_refresh
v4.7 52b6f46bc163 ("mm: /proc/sys/vm/stat_refresh to force vmstat update")
introduced vmstat_refresh(), with its vmstat underflow checking; then v4.8 75ef71840539 ("mm, vmstat: add infrastructure for per-node vmstats") split
NR_VM_NODE_STAT_ITEMS out of NR_VM_ZONE_STAT_ITEMS without updating
vmstat_refresh(): so it has been missing out much of the vmstat underflow
checking ever since. Reinstate it. Thanks to Roman Gushchin
<guro@fb.com> for tangentially pointing this out.
Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2102251502240.13363@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Chengyang Fan [Tue, 13 Apr 2021 22:20:55 +0000 (08:20 +1000)]
mm/ksm: remove unused parameter from remove_trailing_rmap_items()
Since commit 6514d511dbe5 ("ksm: singly-linked rmap_list") was merged,
remove_trailing_rmap_items() doesn't use the 'mm_slot' parameter. So
remove it, and update caller accordingly.
Link: https://lkml.kernel.org/r/20210330121320.1693474-1-cy.fan@huawei.com Signed-off-by: Chengyang Fan <cy.fan@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Miaohe Lin [Tue, 13 Apr 2021 22:20:54 +0000 (08:20 +1000)]
ksm: fix potential missing rmap_item for stable_node
When removing rmap_item from stable tree, STABLE_FLAG of rmap_item is
cleared with head reserved. So the following scenario might happen: For
ksm page with rmap_item1:
cmp_and_merge_page
stable_node->head = &migrate_nodes;
remove_rmap_item_from_tree, but head still equal to stable_node;
try_to_merge_with_ksm_page failed;
return;
For the same ksm page with rmap_item2, stable node migration succeed this
time. The stable_node->head does not equal to migrate_nodes now. For ksm
page with rmap_item1 again:
We would miss the rmap_item for stable_node and might result in failed
rmap_walk_ksm(). Fix this by set rmap_item->head to NULL when rmap_item
is removed from stable tree.
Link: https://lkml.kernel.org/r/20210330140228.45635-5-linmiaohe@huawei.com Fixes: 4146d2d673e8 ("ksm: make !merge_across_nodes migration safe") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Miaohe Lin [Tue, 13 Apr 2021 22:20:54 +0000 (08:20 +1000)]
ksm: remove dedicated macro KSM_FLAG_MASK
The macro KSM_FLAG_MASK is used in rmap_walk_ksm() only. So we can
replace ~KSM_FLAG_MASK with PAGE_MASK to remove this dedicated macro and
make code more consistent because PAGE_MASK is used elsewhere in this
file.
Miaohe Lin [Tue, 13 Apr 2021 22:20:54 +0000 (08:20 +1000)]
ksm: use GET_KSM_PAGE_NOLOCK to get ksm page in remove_rmap_item_from_tree()
It's unnecessary to lock the page when get ksm page if we're going to
remove the rmap item as page migration is irrelevant in this case. Use
GET_KSM_PAGE_NOLOCK instead to save some page lock cycles.
Miaohe Lin [Tue, 13 Apr 2021 22:20:54 +0000 (08:20 +1000)]
ksm: remove redundant VM_BUG_ON_PAGE() on stable_tree_search()
Patch series "Cleanup and fixup for ksm".
This series contains cleanups to remove unnecessary VM_BUG_ON_PAGE and
dedicated macro KSM_FLAG_MASK. Also this fixes potential missing
rmap_item for stable_node which would result in failed rmap_walk_ksm().
More details can be found in the respective changelogs.
This patch (of 4):
The same VM_BUG_ON_PAGE() check is already done in the callee. Remove
these extra caller one to simplify code slightly.
Minchan Kim [Tue, 13 Apr 2021 22:20:53 +0000 (08:20 +1000)]
mm: cma: add the CMA instance name to cma trace events
There were missing places to add cma instance name. To identify each CMA
instance, let's add the name for every cma trace. This patch also changes
the existing cma_trace_alloc to cma_trace_finish since we have
cma_alloc_start[1].
Link: https://lkml.kernel.org/r/20210330220237.748899-1-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Liam Mark <lmark@codeaurora.org> Cc: Georgi Djakov <georgi.djakov@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Minchan Kim [Tue, 13 Apr 2021 22:20:53 +0000 (08:20 +1000)]
mm: cma: support sysfs
Since CMA is getting used more widely, it's more important to keep
monitoring CMA statistics for system health since it's directly related to
user experience.
This patch introduces sysfs statistics for CMA, in order to provide some
basic monitoring of the CMA allocator.
* the number of CMA page successful allocations
* the number of CMA page allocation failures
These two values allow the user to calcuate the allocation
failure rate for each CMA area.
The cma_stat was intentionally allocated by dynamic allocation
to harmonize with kobject lifetime management.
https://lore.kernel.org/linux-mm/YCOAmXqt6dZkCQYs@kroah.com/
Link: https://lkml.kernel.org/r/20210324230759.2213957-1-minchan@kernel.org Link: https://lore.kernel.org/linux-mm/20210316100433.17665-1-colin.king@canonical.com/ Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Colin Ian King <colin.king@canonical.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Tested-by: Anders Roxell <anders.roxell@linaro.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: John Dias <joaodias@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Colin Ian King <colin.king@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Georgi Djakov [Tue, 13 Apr 2021 22:20:52 +0000 (08:20 +1000)]
mm: cma: Add the CMA instance name to the cma_alloc_start trace event
During CMA allocation, print also the name to identify the CMA instance.
Link: https://lkml.kernel.org/r/20210326155414.25006-1-georgi.djakov@linaro.org Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org> Suggested-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Liam Mark [Tue, 13 Apr 2021 22:20:52 +0000 (08:20 +1000)]
mm: cma: add trace events for CMA alloc perf testing
Add cma and migrate trace events to enable CMA allocation performance to
be measured via ftrace.
Link: https://lkml.kernel.org/r/20210324160740.15901-1-georgi.djakov@linaro.org Signed-off-by: Liam Mark <lmark@codeaurora.org> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Baolin Wang [Tue, 13 Apr 2021 22:20:52 +0000 (08:20 +1000)]
mm: cma: use pr_err_ratelimited for CMA warning
If we did not reserve extra CMA memory, the log buffer can be easily
filled up by CMA failure warning when the devices calling
dmam_alloc_coherent() to alloc DMA memory. Thus we can use
pr_err_ratelimited() instead to reduce the duplicate CMA warning.
Minchan Kim [Tue, 13 Apr 2021 22:20:52 +0000 (08:20 +1000)]
mm: vmstat: add cma statistics
Since CMA is used more widely, it's worth to have CMA allocation
statistics into vmstat. With it, we could know how agressively system
uses cma allocation and how often it fails.
Link: https://lkml.kernel.org/r/20210302183346.3707237-1-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: John Dias <joaodias@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Since commit c77c5cbafe54 ("mm: migrate: skip shared exec THP for NUMA
balancing"), the NUMA balancing would skip shared exec transhuge page.
But this enhancement is not suitable for transhuge page. Because it's
required that page_mapcount() must be 1 due to no migration pte dance is
done here. On the other hand, the shared exec transhuge page will leave
the migrate_misplaced_page() with pte entry untouched and page locked.
Thus pagefault for NUMA will be triggered again and deadlock occurs when
we start waiting for the page lock held by ourselves.
Yang Shi said:
"Thanks for catching this. By relooking the code I think the other
important reason for removing this is
migrate_misplaced_transhuge_page() actually can't see shared exec
file THP at all since page_lock_anon_vma_read() is called before
and if page is not anonymous page it will just restore the PMD
without migrating anything.
The pages for private mapped file vma may be anonymous pages due to
COW but they can't be THP so it won't trigger THP numa fault at all. I
think this is why no bug was reported. I overlooked this in the first
place."
Link: https://lkml.kernel.org/r/20210325131524.48181-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Miaohe Lin [Tue, 13 Apr 2021 22:20:51 +0000 (08:20 +1000)]
mm/migrate.c: use helper migrate_vma_collect_skip() in migrate_vma_collect_hole()
It's more recommended to use helper function migrate_vma_collect_skip() to
skip the unexpected case and it also helps remove some duplicated codes.
Move migrate_vma_collect_skip() above migrate_vma_collect_hole() to avoid
compiler warning.
Link: https://lkml.kernel.org/r/20210325131524.48181-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Miaohe Lin [Tue, 13 Apr 2021 22:20:51 +0000 (08:20 +1000)]
mm/migrate.c: fix potential indeterminate pte entry in migrate_vma_insert_page()
If the zone device page does not belong to un-addressable device memory,
the variable entry will be uninitialized and lead to indeterminate pte
entry ultimately. Fix this unexpected case and warn about it.
Link: https://lkml.kernel.org/r/20210325131524.48181-4-linmiaohe@huawei.com Fixes: df6ad69838fc ("mm/device-public-memory: device memory cache coherent with CPU") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Miaohe Lin [Tue, 13 Apr 2021 22:20:50 +0000 (08:20 +1000)]
mm/migrate.c: remove unnecessary rc != MIGRATEPAGE_SUCCESS check in 'else' case
It's guaranteed that in the 'else' case of the rc == MIGRATEPAGE_SUCCESS
check, rc does not equal to MIGRATEPAGE_SUCCESS. Remove this unnecessary
check.
Link: https://lkml.kernel.org/r/20210325131524.48181-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Miaohe Lin [Tue, 13 Apr 2021 22:20:50 +0000 (08:20 +1000)]
mm/migrate.c: make putback_movable_page() static
Patch series "Cleanup and fixup for mm/migrate.c", v3.
This series contains cleanups to remove unnecessary VM_BUG_ON_PAGE and rc
!= MIGRATEPAGE_SUCCESS check. Also use helper function to remove some
duplicated codes. What's more, this fixes potential deadlock in NUMA
balancing shared exec THP case and so on. More details can be found in
the respective changelogs.
This patch (of 5):
The putback_movable_page() is just called by putback_movable_pages() and
we know the page is locked and both PageMovable() and PageIsolated() is
checked right before calling putback_movable_page(). So we make it static
and remove all the 3 VM_BUG_ON_PAGE().
Minchan Kim [Tue, 13 Apr 2021 22:20:50 +0000 (08:20 +1000)]
mm: fs: invalidate BH LRU during page migration
Pages containing buffer_heads that are in one of the per-CPU buffer_head
LRU caches will be pinned and thus cannot be migrated. This can prevent
CMA allocations from succeeding, which are often used on platforms with
co-processors (such as a DSP) that can only use physically contiguous
memory. It can also prevent memory hot-unplugging from succeeding, which
involves migrating at least MIN_MEMORY_BLOCK_SIZE bytes of memory, which
ranges from 8 MiB to 1 GiB based on the architecture in use.
Correspondingly, invalidate the BH LRU caches before a migration starts
and stop any buffer_head from being cached in the LRU caches, until
migration has finished.
Link: https://lkml.kernel.org/r/20210319175127.886124-3-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Chris Goldsworthy <cgoldswo@codeaurora.org> Reported-by: Laura Abbott <labbott@kernel.org> Tested-by: Oliver Sang <oliver.sang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: John Dias <joaodias@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Minchan Kim [Tue, 13 Apr 2021 22:20:49 +0000 (08:20 +1000)]
mm: replace migrate_[prep|finish] with lru_cache_[disable|enable]
Currently, migrate_[prep|finish] is merely a wrapper of
lru_cache_[disable|enable]. There is not much to gain from having
additional abstraction.
Use lru_cache_[disable|enable] instead of migrate_[prep|finish], which
would be more descriptive.
note: migrate_prep_local in compaction.c changed into lru_add_drain to
avoid CPU schedule cost with involving many other CPUs to keep old
behavior.
Link: https://lkml.kernel.org/r/20210319175127.886124-2-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Chris Goldsworthy <cgoldswo@codeaurora.org> Cc: John Dias <joaodias@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oliver Sang <oliver.sang@intel.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Minchan Kim [Tue, 13 Apr 2021 22:20:49 +0000 (08:20 +1000)]
mm: disable LRU pagevec during the migration temporarily
LRU pagevec holds refcount of pages until the pagevec are drained. It
could prevent migration since the refcount of the page is greater than the
expection in migration logic. To mitigate the issue, callers of
migrate_pages drains LRU pagevec via migrate_prep or lru_add_drain_all
before migrate_pages call.
However, it's not enough because pages coming into pagevec after the
draining call still could stay at the pagevec so it could keep preventing
page migration. Since some callers of migrate_pages have retrial logic
with LRU draining, the page would migrate at next trail but it is still
fragile in that it doesn't close the fundamental race between upcoming LRU
pages into pagvec and migration so the migration failure could cause
contiguous memory allocation failure in the end.
To close the race, this patch disables lru caches(i.e, pagevec) during
ongoing migration until migrate is done.
Since it's really hard to reproduce, I measured how many times
migrate_pages retried with force mode(it is about a fallback to a sync
migration) with below debug code.
int migrate_pages(struct list_head *from, new_page_t get_new_page,
..
..
The test was repeating android apps launching with cma allocation in
background every five seconds. Total cma allocation count was about 500
during the testing. With this patch, the dump_page count was reduced from
400 to 30.
The new interface is also useful for memory hotplug which currently drains
lru pcp caches after each migration failure. This is rather suboptimal as
it has to disrupt others running during the operation. With the new
interface the operation happens only once. This is also in line with pcp
allocator cache which are disabled for the offlining as well.
Link: https://lkml.kernel.org/r/20210319175127.886124-1-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Chris Goldsworthy <cgoldswo@codeaurora.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: John Dias <joaodias@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Oliver Sang <oliver.sang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
mm: compaction: update the COMPACT[STALL|FAIL] events properly
By definition, COMPACT[STALL|FAIL] events needs to be counted when there
is 'At least in one zone compaction wasn't deferred or skipped from the
direct compaction'. And when compaction is skipped or deferred,
COMPACT_SKIPPED will be returned but it will still go and update these
compaction events which is wrong in the sense that COMPACT[STALL|FAIL] is
counted without even trying the compaction.
Correct this by skipping the counting of these events when COMPACT_SKIPPED
is returned for compaction. This indirectly also avoid the unnecessary
try into the get_page_from_freelist() when compaction is not even tried.
There is a corner case where compaction is skipped but still count
COMPACTSTALL event, which is that IRQ came and freed the page and the same
is captured in capture_control.
Link: https://lkml.kernel.org/r/1613151184-21213-1-git-send-email-charante@codeaurora.org Signed-off-by: Charan Teja Reddy <charante@codeaurora.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
The sysctl_compact_memory is mostly unused in mm/compaction.c
It just acts as a place holder for sysctl to store .data.
But the .data itself is not needed here.
So we can get ride of this variable completely and make .data as NULL.
This will also eliminate the extern declaration from header file.
No functionality is broken or changed this way.
Yang Shi [Tue, 13 Apr 2021 22:20:48 +0000 (08:20 +1000)]
mm: vmscan: shrink deferred objects proportional to priority
The number of deferred objects might get windup to an absurd number, and
it results in clamp of slab objects. It is undesirable for sustaining
workingset.
So shrink deferred objects proportional to priority and cap nr_deferred to
twice of cache items.
The idea is borrowed from Dave Chinner's patch:
https://lore.kernel.org/linux-xfs/20191031234618.15403-13-david@fromorbit.com/
Tested with kernel build and vfs metadata heavy workload in our production
environment, no regression is spotted so far.
Link: https://lkml.kernel.org/r/20210311190845.9708-14-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Yang Shi [Tue, 13 Apr 2021 22:20:48 +0000 (08:20 +1000)]
mm: vmscan: don't need allocate shrinker->nr_deferred for memcg aware shrinkers
Now nr_deferred is available on per memcg level for memcg aware shrinkers,
so don't need allocate shrinker->nr_deferred for such shrinkers anymore.
The prealloc_memcg_shrinker() would return -ENOSYS if !CONFIG_MEMCG or
memcg is disabled by kernel command line, then shrinker's
SHRINKER_MEMCG_AWARE flag would be cleared. This makes the implementation
of this patch simpler.
Link: https://lkml.kernel.org/r/20210311190845.9708-12-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Roman Gushchin <guro@fb.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
projects / users / jedix / linux-maple.git / log