Update free_pgtables(), unmap_vmas(), and zap_page_range() to use the
maple tree.
Use the new free_pgtables() and unmap_vmas() in do_mas_align_munmap(). At
the same time, alter the loop to be more compact.
Now that free_pgtables() and unmap_vmas() take a maple tree as an
argument, rearrange do_mas_align_munmap() to use the new tree to hold the
vmas to remove.
Remove __vma_link_list() and __vma_unlink_list() as they are exclusively
used to update the linked list
Drop linked list update from __insert_vm_struct().
Rework validation of tree as it was depending on the linked list.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
mm/mempolicy: use vma iterator & maple state instead of vma linked list
Reworked the way mbind_range() finds the first VMA to reuse the maple
state and limit the number of tree walks needed.
Note, this drops the VM_BUG_ON(!vma) call, which would catch a start
address higher than the last VMA. The code was written in a way that
allowed no VMA updates to occur and still return success. There should be
no functional change to this scenario with the new code.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
The linked list is slower than walking the VMAs using the maple tree. We
can't use the VMA iterator here because it doesn't support moving to an
earlier position.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
The VMA iterator is faster than the linked llist, and it can be walked
even when VMAs are being removed from the address space, so there's no
need to keep track of 'next'.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Use the Maple Tree iterator instead. This is too complicated for the VMA
iterator to handle, so let's open-code it for now. If this turns out to
be a common pattern, we can migrate it to common code.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Use the VMA iterator instead. This requires a little restructuring of the
surrounding code to hoist the mm to the caller. That turns
cxl_prefault_one() into a trivial function, so call cxl_fault_segment()
directly.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
Use the VMA iterator instead. Since VMA can no longer be NULL in the
loop, then deal with out-of-memory outside the loop. This means a
slightly longer run time in the failure case (-ENOMEM) - it will run to
the end of the VMAs before erroring instead of in the middle of the loop.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
mm/mmap: change do_brk_munmap() to use do_mas_align_munmap()
do_brk_munmap() has already aligned the address and has a maple tree state
to be used. Use the new do_mas_align_munmap() to avoid unnecessary
alignment and error checks.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Remove __do_munmap() in favour of do_munmap(), do_mas_munmap(), and
do_mas_align_munmap().
do_munmap() is a wrapper to create a maple state for any callers that have
not been converted to the maple tree.
do_mas_munmap() takes a maple state to mumap a range. This is just a
small function which checks for error conditions and aligns the end of the
range.
do_mas_align_munmap() uses the aligned range to mumap a range.
do_mas_align_munmap() starts with the first VMA in the range, then finds
the last VMA in the range. Both start and end are split if necessary.
Then the VMAs are removed from the linked list and the mm mlock count is
updated at the same time. Followed by a single tree operation of
overwriting the area in with a NULL. Finally, the detached list is
unmapped and freed.
By reorganizing the munmap calls as outlined, it is now possible to avoid
extra work of aligning pre-aligned callers which are known to be safe,
avoid extra VMA lookups or tree walks for modifications.
detach_vmas_to_be_unmapped() is no longer used, so drop this code.
vm_brk_flags() can just call the do_mas_munmap() as it checks for
intersecting VMAs directly.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
By using the maple tree and the maple tree state, the vmacache is no
longer beneficial and is complicating the VMA code. Remove the vmacache
to reduce the work in keeping it up to date and code complexity.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
mm/mmap: use advanced maple tree API for mmap_region()
Changing mmap_region() to use the maple tree state and the advanced maple
tree interface allows for a lot less tree walking.
This change removes the last caller of munmap_vma_range(), so drop this
unused function.
Add vma_expand() to expand a VMA if possible by doing the necessary
hugepage check, uprobe_munmap of files, dcache flush, modifications then
undoing the detaches, etc.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
mm/mmap: change do_brk_flags() to expand existing VMA and add do_brk_munmap()
Avoid allocating a new VMA when it a vma modification can occur. When a
brk() can expand or contract a VMA, then the single store operation will
only modify one index of the maple tree instead of causing a node to split
or coalesce. This avoids unnecessary allocations/frees of maple tree
nodes and VMAs.
Move some limit & flag verifications out of the do_brk_flags() function to
use only relevant checks in the code path of bkr() and vm_brk_flags().
Set the vma to check if it can expand in vm_brk_flags() if extra criteria
are met.
Drop userfaultfd from do_brk_flags() path and only use it in
vm_brk_flags() path since that is the only place a munmap will happen.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
mm/khugepaged: optimize collapse_pte_mapped_thp() by using vma_lookup()
vma_lookup() will walk the vma tree once and not continue to look for the
next vma. Since the exact vma is checked below, this is a more optimal
way of searching.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Use vma_lookup() to walk the tree to the start value requested. If the
vma at the start does not match, then the answer is NULL and there is no
need to look at the next vma the way that find_vma() would.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
vma_lookup() walks the VMA tree for a specific value, find_vma() will
search the tree after walking to a specific value. It is more efficient
to only walk to the requested value since privcmd_ioctl_mmap() will exit
the loop if vm_start != msg->va.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
mmap: change zeroing of maple tree in __vma_adjust()
Only write to the maple tree if we are not inserting or the insert isn't
going to overwrite the area to clear. This avoids spanning writes and
node coealescing when unnecessary.
The change requires a custom search for the linked list addition to find
the correct VMA for the prev link.
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
damon: Convert __damon_va_three_regions to use the VMA iterator
This rather specialised walk can use the VMA iterator. If this proves to
be too slow, we can write a custom routine to find the two largest gaps,
but it will be somewhat complicated, so let's see if we need it first.
Update the kunit test case to use the maple tree. This also fixes an
issue with the kunit testcase not adding the last VMA to the list.
Fixes: 17ccae8bb5c9 (mm/damon: add kunit tests) Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: SeongJae Park <sj@kernel.org>
kernel/fork: use maple tree for dup_mmap() during forking
The maple tree was already tracking VMAs in this function by an earlier
commit, but the rbtree iterator was being used to iterate the list.
Change the iterator to use a maple tree native iterator and switch to the
maple tree advanced API to avoid multiple walks of the tree during insert
operations. Unexport the now-unused vma_store() function.
For performance reasons we bulk allocate the maple tree nodes. The node
calculations are done internally to the tree and use the VMA count and
assume the worst-case node requirements. The VM_DONT_COPY flag does not
allow for the most efficient copy method of the tree and so a bulk loading
algorithm is used.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz>
mm/mmap: use maple tree for unmapped_area{_topdown}
The maple tree code was added to find the unmapped area in a previous
commit and was checked against what the rbtree returned, but the actual
result was never used. Start using the maple tree implementation and
remove the rbtree code.
Add kernel documentation comment for these functions.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
mm/mmap: use the maple tree for find_vma_prev() instead of the rbtree
Use the maple tree's advanced API and a maple state to walk the tree for
the entry at the address of the next vma, then use the maple state to walk
back one entry to find the previous entry.
Add kernel documentation comments for this API.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz>
This thin layer of abstraction over the maple tree state is for iterating
over VMAs. You can go forwards, go backwards or ask where the iterator
is. Rename the existing vma_next() to __vma_next() -- it will be removed
by the end of this series.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
Start tracking the VMAs with the new maple tree structure in parallel with
the rb_tree. Add debug and trace events for maple tree operations and
duplicate the rb_tree that is created on forks into the maple tree.
The maple tree is added to the mm_struct including the mm_init struct,
added support in required mm/mmap functions, added tracking in kernel/fork
for process forking, and used to find the unmapped_area and checked
against what the rbtree finds.
This also moves the mmap_lock() in exit_mmap() since the oom reaper call
does walk the VMAs. Otherwise lockdep will be unhappy if oom happens.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
radix tree test suite: add allocation counts and size to kmem_cache
Add functions to get the number of allocations, and total allocations from
a kmem_cache. Also add a function to get the allocated size and a way to
zero the total allocations.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
radix tree test suite: add kmem_cache_set_non_kernel()
kmem_cache_set_non_kernel() is a mechanism to allow a certain number of
kmem_cache_alloc requests to succeed even when GFP_KERNEL is not set in
the flags. This functionality allows for testing different paths though
the code.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel that a
non-overlapping range-based tree would be beneficial, especially one with a
simple interface. If you use an rbtree with other data structures to improve
performance or an interval tree to track non-overlapping ranges, then this is
for you.
The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf nodes.
With the increased branching factor, it is significantly shorter than the
rbtree so it has fewer cache misses. The removal of the linked list between
subsequent entries also reduces the cache misses and the need to pull in the
previous and next VMA during many tree alterations.
The first user that is covered in this patch set is the vm_area_struct, where
three data structures are replaced by the maple tree: the augmented rbtree, the
vma cache, and the linked list of VMAs in the mm_struct. The long term goal is
to reduce or remove the mmap_lock contention.
The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be allowed
at a time. A reader re-walks if stale data is encountered. VMAs would be RCU
enabled and this mode would be entered once multiple tasks are using the
mm_struct.
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: David Howells <dhowells@redhat.com>
Hailong Tu [Fri, 29 Apr 2022 21:37:00 +0000 (14:37 -0700)]
mm/damon/reclaim: fix the timer always stays active
The timer stays active even if the reclaim mechanism is never enabled. It
is unnecessary overhead can be completely avoided by using
module_param_cb() for enabled flag.
damon: vaddr-test: tweak code to make the logic clearer
Move these two lines into the damon_for_each_region loop, it is always for
testing the last region. And also avoid to use a list iterator 'r'
outside the loop which is considered harmful[1].
Currently, alloc_anon_noexit() calls alloc_anon() which instantly frees
the allocated memory. alloc_anon_noexit() is usually used with
cg_run_nowait() to run a process in the background that allocates
memory. It makes sense for the background process to keep the memory
allocated and not instantly free it (otherwise there is no point of
running it in the background).
Link: https://lkml.kernel.org/r/20220425190040.2475377-4-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Chen Wandun <chenwandun@huawei.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michal Koutn" <mkoutny@suse.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Wei Xu <weixugc@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch series adds a memory.reclaim proactive reclaim interface.
The rationale behind the interface and how it works are in the first
patch.
This patch (of 4):
Introduce a memcg interface to trigger memory reclaim on a memory cgroup.
Use case: Proactive Reclaim
---------------------------
A userspace proactive reclaimer can continuously probe the memcg to
reclaim a small amount of memory. This gives more accurate and up-to-date
workingset estimation as the LRUs are continuously sorted and can
potentially provide more deterministic memory overcommit behavior. The
memory overcommit controller can provide more proactive response to the
changing behavior of the running applications instead of being reactive.
A userspace reclaimer's purpose in this case is not a complete replacement
for kswapd or direct reclaim, it is to proactively identify memory savings
opportunities and reclaim some amount of cold pages set by the policy to
free up the memory for more demanding jobs or scheduling new jobs.
A user space proactive reclaimer is used in Google data centers.
Additionally, Meta's TMO paper recently referenced a very similar
interface used for user space proactive reclaim:
https://dl.acm.org/doi/pdf/10.1145/3503222.3507731
Benefits of a user space reclaimer:
-----------------------------------
1) More flexible on who should be charged for the cpu of the memory
reclaim. For proactive reclaim, it makes more sense to be centralized.
2) More flexible on dedicating the resources (like cpu). The memory
overcommit controller can balance the cost between the cpu usage and
the memory reclaimed.
3) Provides a way to the applications to keep their LRUs sorted, so,
under memory pressure better reclaim candidates are selected. This
also gives more accurate and uptodate notion of working set for an
application.
Why memory.high is not enough?
------------------------------
- memory.high can be used to trigger reclaim in a memcg and can
potentially be used for proactive reclaim. However there is a big
downside in using memory.high. It can potentially introduce high
reclaim stalls in the target application as the allocations from the
processes or the threads of the application can hit the temporary
memory.high limit.
- Userspace proactive reclaimers usually use feedback loops to decide
how much memory to proactively reclaim from a workload. The metrics
used for this are usually either refaults or PSI, and these metrics will
become messy if the application gets throttled by hitting the high
limit.
- memory.high is a stateful interface, if the userspace proactive
reclaimer crashes for any reason while triggering reclaim it can leave
the application in a bad state.
- If a workload is rapidly expanding, setting memory.high to proactively
reclaim memory can result in actually reclaiming more memory than
intended.
The benefits of such interface and shortcomings of existing interface were
further discussed in this RFC thread:
https://lore.kernel.org/linux-mm/5df21376-7dd1-bf81-8414-32a73cea45dd@google.com/
Interface:
----------
Introducing a very simple memcg interface 'echo 10M > memory.reclaim' to
trigger reclaim in the target memory cgroup.
The interface is introduced as a nested-keyed file to allow for future
optional arguments to be easily added to configure the behavior of
reclaim.
Possible Extensions:
--------------------
- This interface can be extended with an additional parameter or flags
to allow specifying one or more types of memory to reclaim from (e.g.
file, anon, ..).
- The interface can also be extended with a node mask to reclaim from
specific nodes. This has use cases for reclaim-based demotion in memory
tiering systens.
- A similar per-node interface can also be added to support proactive
reclaim and reclaim-based demotion in systems without memcg.
- Add a timeout parameter to make it easier for user space to call the
interface without worrying about being blocked for an undefined amount
of time.
For now, let's keep things simple by adding the basic functionality.
[yosryahmed@google.com: worked on versions v2 onwards, refreshed to
current master, updated commit message based on recent
discussions and use cases] Link: https://lkml.kernel.org/r/20220425190040.2475377-1-yosryahmed@google.com Link: https://lkml.kernel.org/r/20220425190040.2475377-2-yosryahmed@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Co-developed-by: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Wei Xu <weixugc@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: David Rientjes <rientjes@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Thelen <gthelen@google.com> Cc: Chen Wandun <chenwandun@huawei.com> Cc: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: "Michal Koutn" <mkoutny@suse.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Brian Geffon [Fri, 29 Apr 2022 21:36:59 +0000 (14:36 -0700)]
zram: add a huge_idle writeback mode
Today it's only possible to write back as a page, idle, or huge. A user
might want to writeback pages which are huge and idle first as these idle
pages do not require decompression and make a good first pass for
writeback.
Idle writeback specifically has the advantage that a refault is unlikely
given that the page has been swapped for some amount of time without being
refaulted.
Huge writeback has the advantage that you're guaranteed to get the maximum
benefit from a single page writeback, that is, you're reclaiming one full
page of memory. Pages which are compressed in zram being written back
result in some benefit which is always less than a page size because of
the fact that it was compressed.
The primary use of this is for minimizing refaults in situations where the
device has to be sensitive to storage endurance. On ChromeOS we have
devices with slow eMMC and repeated writes and refaults can negatively
affect performance and endurance.
Link: https://lkml.kernel.org/r/20220322215821.1196994-1-bgeffon@google.com Signed-off-by: Brian Geffon <bgeffon@google.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kasan: fix sleeping function called from invalid context on RT kernel
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
preempt_count: 1, expected: 0
...........
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.1-rt16-yocto-preempt-rt #22
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x60/0x8c
dump_stack+0x10/0x12
__might_resched.cold+0x13b/0x173
rt_spin_lock+0x5b/0xf0
___cache_free+0xa5/0x180
qlist_free_all+0x7a/0x160
per_cpu_remove_cache+0x5f/0x70
smp_call_function_many_cond+0x4c4/0x4f0
on_each_cpu_cond_mask+0x49/0xc0
kasan_quarantine_remove_cache+0x54/0xf0
kasan_cache_shrink+0x9/0x10
kmem_cache_shrink+0x13/0x20
acpi_os_purge_cache+0xe/0x20
acpi_purge_cached_objects+0x21/0x6d
acpi_initialize_objects+0x15/0x3b
acpi_init+0x130/0x5ba
do_one_initcall+0xe5/0x5b0
kernel_init_freeable+0x34f/0x3ad
kernel_init+0x1e/0x140
ret_from_fork+0x22/0x30
When the kmem_cache_shrink() was called, the IPI was triggered, the
___cache_free() is called in IPI interrupt context, the local-lock or
spin-lock will be acquired. On PREEMPT_RT kernel, these locks are
replaced with sleepbale rt-spinlock, so the above problem is triggered.
Fix it by moving the qlist_free_allfrom() from IPI interrupt context to
task context when PREEMPT_RT is enabled.
[akpm@linux-foundation.org: reduce ifdeffery] Link: https://lkml.kernel.org/r/20220401134649.2222485-1-qiang1.zhang@intel.com Signed-off-by: Zqiang <qiang1.zhang@intel.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Fri, 29 Apr 2022 21:36:58 +0000 (14:36 -0700)]
mm: hugetlb: add missing cache flushing in hugetlb_unshare_all_pmds()
Missed calling flush_cache_range() before removing the sharing PMD
entrires, otherwise data consistence issue may be occurred on some
architectures whose caches are strict and require a virtual>physical
translation to exist for a virtual address. Thus add it.
Now no architectures enabling PMD sharing will be affected, since they do
not have a VIVT cache. That means this issue can not be happened in
practice so far.
Peng Liu [Fri, 29 Apr 2022 21:36:57 +0000 (14:36 -0700)]
hugetlb: fix return value of __setup handlers
When __setup() return '0', using invalid option values causes the entire
kernel boot option string to be reported as Unknown. Hugetlb calls
__setup() and will return '0' when set invalid parameter string.
The following phenomenon is observed:
cmdline:
hugepagesz=1Y hugepages=1
dmesg:
HugeTLB: unsupported hugepagesz=1Y
HugeTLB: hugepages=1 does not follow a valid hugepagesz, ignoring
Unknown kernel command line parameters "hugepagesz=1Y hugepages=1"
Since hugetlb will print warning/error information before return for
invalid parameter string, just use return '1' to avoid print again.
Link: https://lkml.kernel.org/r/20220413032915.251254-4-liupeng256@huawei.com Signed-off-by: Peng Liu <liupeng256@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: Liu Yuntao <liuyuntao10@huawei.com> Cc: Zhenguo Yao <yaozhenguo1@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peng Liu [Fri, 29 Apr 2022 21:36:57 +0000 (14:36 -0700)]
hugetlb: fix hugepages_setup when deal with pernode
Hugepages can be specified to pernode since "hugetlbfs: extend the
definition of hugepages parameter to support node allocation", but the
following problem is observed.
Confusing behavior is observed when both 1G and 2M hugepage is set
after "numa=off".
cmdline hugepage settings:
hugepagesz=1G hugepages=0:3,1:3
hugepagesz=2M hugepages=0:1024,1:1024
results:
HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages
HugeTLB registered 2.00 MiB page size, pre-allocated 1024 pages
Furthermore, confusing behavior can be also observed when an invalid node
behind a valid node. To fix this, never allocate any typical hugepage
when an invalid parameter is received.
Link: https://lkml.kernel.org/r/20220413032915.251254-3-liupeng256@huawei.com Fixes: b5389086ad7b ("hugetlbfs: extend the definition of hugepages parameter to support node allocation") Signed-off-by: Peng Liu <liupeng256@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Liu Yuntao <liuyuntao10@huawei.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Zhenguo Yao <yaozhenguo1@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peng Liu [Fri, 29 Apr 2022 21:36:57 +0000 (14:36 -0700)]
hugetlb: fix wrong use of nr_online_nodes
Patch series "hugetlb: Fix some incorrect behavior", v3.
This series fix three bugs of hugetlb:
1) Invalid use of nr_online_nodes;
2) Inconsistency between 1G hugepage and 2M hugepage;
3) Useless information in dmesg.
This patch (of 4):
Certain systems are designed to have sparse/discontiguous nodes. In this
case, nr_online_nodes can not be used to walk through numa node. Also, a
valid node may be greater than nr_online_nodes.
However, in hugetlb, it is assumed that nodes are contiguous.
For sparse/discontiguous nodes, the current code may treat a valid node
as invalid, and will fail to allocate all hugepages on a valid node that
"nid >= nr_online_nodes".
As David suggested:
if (tmp >= nr_online_nodes)
goto invalid;
Just imagine node 0 and node 2 are online, and node 1 is offline.
Assuming that "node < 2" is valid is wrong.
Recheck all the places that use nr_online_nodes, and repair them one by
one.
[liupeng256@huawei.com: v4] Link: https://lkml.kernel.org/r/20220416103526.3287348-1-liupeng256@huawei.com Link: https://lkml.kernel.org/r/20220413032915.251254-1-liupeng256@huawei.com Link: https://lkml.kernel.org/r/20220413032915.251254-2-liupeng256@huawei.com Fixes: 4178158ef8ca ("hugetlbfs: fix issue of preallocation of gigantic pages can't work") Fixes: b5389086ad7b ("hugetlbfs: extend the definition of hugepages parameter to support node allocation") Fixes: e79ce9832316 ("hugetlbfs: fix a truncation issue in hugepages parameter") Fixes: f9317f77a6e0 ("hugetlb: clean up potential spectre issue warnings") Signed-off-by: Peng Liu <liupeng256@huawei.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Zhenguo Yao <yaozhenguo1@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Liu Yuntao <liuyuntao10@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
drivers/base/memory: fix an unlikely reference counting issue in __add_memory_block()
__add_memory_block() calls both put_device() and device_unregister() when
storing the memory block into the xarray. This is incorrect because
xarray doesn't take an additional reference and device_unregister()
already calls put_device().
Triggering the issue looks really unlikely and its only effect should be
to log a spurious warning about a ref counted issue.
Link: https://lkml.kernel.org/r/d44c63d78affe844f020dc02ad6af29abc448fc4.1650611702.git.christophe.jaillet@wanadoo.fr Fixes: 4fb6eabf1037 ("drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Scott Cheloha <cheloha@linux.vnet.ibm.com> Cc: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 29 Apr 2022 06:16:19 +0000 (23:16 -0700)]
mm: compaction: make sure highest is above the min_pfn
It's not guaranteed that highest will be above the min_pfn. If highest is
below the min_pfn, migrate_pfn and free_pfn can meet prematurely and lead
to some useless work. Make sure highest is above min_pfn to avoid making
a futile effort.
Link: https://lkml.kernel.org/r/20220418141253.24298-13-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 29 Apr 2022 06:16:19 +0000 (23:16 -0700)]
mm: compaction: simplify the code in __compact_finished
Since commit efe771c7603b ("mm, compaction: always finish scanning of a
full pageblock"), compaction will always finish scanning a pageblock. And
migrate_pfn is assured to align with pageblock_nr_pages when we reach
here. So we will always return COMPACT_SUCCESS if a suitable fallback is
found due to the below IS_ALIGNED check of migrate_pfn. Simplify the code
to make this clear and improve the readability. No functional change
intended.
Link: https://lkml.kernel.org/r/20220418141253.24298-12-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 29 Apr 2022 06:16:18 +0000 (23:16 -0700)]
mm: compaction: make compaction_zonelist_suitable return false when COMPACT_SUCCESS
When compact_result indicates that the allocation should now succeed, i.e.
compact_result = COMPACT_SUCCESS, compaction_zonelist_suitable should
return false because there is no need to do compaction now.
Link: https://lkml.kernel.org/r/20220418141253.24298-11-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 29 Apr 2022 06:16:18 +0000 (23:16 -0700)]
mm: compaction: avoid possible NULL pointer dereference in kcompactd_cpu_online
It's possible that kcompactd_run could fail to run kcompactd for a hot
added node and leave pgdat->kcompactd as NULL. So pgdat->kcompactd should
be checked here to avoid possible NULL pointer dereference.
Link: https://lkml.kernel.org/r/20220418141253.24298-10-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 29 Apr 2022 06:16:18 +0000 (23:16 -0700)]
mm: compaction: clean up comment about async compaction in isolate_migratepages
Since commit 282722b0d258 ("mm, compaction: restrict async compaction to
pageblocks of same migratetype"), async direct compaction is restricted to
scan the pageblocks of same migratetype. Correct the comment accordingly.
Link: https://lkml.kernel.org/r/20220418141253.24298-9-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 29 Apr 2022 06:16:17 +0000 (23:16 -0700)]
mm: compaction: clean up comment about suitable migration target recheck
checked_pageblock is already removed and suitable_migration_target is not
rechecked under the zone lock since commit f8224aa5a0a4 ("mm, compaction:
do not recheck suitable_migration_target under lock"). Correct the
comment accordingly.
Link: https://lkml.kernel.org/r/20220418141253.24298-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 29 Apr 2022 06:16:17 +0000 (23:16 -0700)]
mm: compaction: clean up comment for sched contention
Since commit cf66f0700c8f ("mm, compaction: do not consider a need to
reschedule as contention"), async compaction won't abort when scheduling
is needed. Correct the relevant comment accordingly.
Link: https://lkml.kernel.org/r/20220418141253.24298-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 29 Apr 2022 06:16:17 +0000 (23:16 -0700)]
mm: compaction: remove unneeded assignment to isolate_start_pfn
isolate_start_pfn is unused when cc->nr_freepages ! = 0. Otherwise
cc->free_pfn will overwrite it unconditionally. So we should remove this
unneeded and somewhat misleading assignment.
Link: https://lkml.kernel.org/r/20220418141253.24298-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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