Vihas Mak [Wed, 24 Nov 2021 19:04:36 +0000 (00:34 +0530)]
staging: r8188eu: use max() and min() macros
use max() and min() macros to fix following cocci warnings:
drivers/staging/r8188eu/core/rtw_wlan_util.c:719: WARNING opportunity for min()
drivers/staging/r8188eu/core/rtw_wlan_util.c:724: WARNING opportunity for max()
After removing the BITSET_T typedef in commit d8a364820e01 ("staging:
vchiq_core: get rid of typedef") the static_assert statement becomes superfluous
as now we are checking if the size of the u32 type is 4 bytes. Hence, just
remove the static_assert statement.
Candy Febriyanto [Thu, 18 Nov 2021 16:37:34 +0000 (23:37 +0700)]
staging: r8188eu: Remove support for devices with 8188FU chipset (0bda:f179)
The new r8188eu driver doesn't actually support devices with vendor ID 0bda
and product ID f179[0][1][2], remove the ID so owners of these devices
don't have to blacklist the staging driver.
Karolina Drobnik [Mon, 15 Nov 2021 10:55:49 +0000 (10:55 +0000)]
staging: vt6655: Delete bogus check for `init_count` in AL7230
Remove an unnecessary check in `rf_write_wake_prog_syn` in `RF_AIROHA7230`
switch case. This `if` conditional will never be true as `init_count` is
equal to 18 and can't be bigger than `MISCFIFO_SYNDATASIZE - 0`, which
is equal to 21.
Karolina Drobnik [Mon, 15 Nov 2021 10:55:48 +0000 (10:55 +0000)]
staging: vt6655: Delete bogus check for `init_count` in AL2230
Remove an unnecessary check in `rf_write_wake_prog_syn` in `RF_AL2230S`
switch case. This `if` conditional will never be true as `init_count` is
equal to 17 and can't be bigger than `MISCFIFO_SYNDATASIZE - 0`, which
is equal to 21.
Karolina Drobnik [Mon, 15 Nov 2021 10:55:43 +0000 (10:55 +0000)]
staging: vt6655: Introduce `idx` variable
Add a local variable to store `MISCFIFO_SYNDATA_IDX` offset.
This change helps in shortening the lines in `rf.c` that
are deemed too long by checkpatch.pl.
Martin Kaiser [Sat, 13 Nov 2021 18:55:11 +0000 (19:55 +0100)]
staging: r8188eu: use efuse map length define directly
The length of the efuse data section is constant. We can use the
corresponding define directly, there's no need to get the length
from rtl8188e_EFUSE_GetEfuseDefinition.
Martin Kaiser [Sat, 13 Nov 2021 18:55:07 +0000 (19:55 +0100)]
staging: r8188eu: merge small adapter info helpers
ReadAdapterInfo8188EU calls Hal_InitPGData88E and readAdapterInfo_8188EU,
both of which are small and have no other callers. Merge the two latter
functions into ReadAdapterInfo8188EU.
Martin Kaiser [Sat, 13 Nov 2021 18:55:06 +0000 (19:55 +0100)]
staging: r8188eu: remove test code for efuse shadow map
The EFUSE_ShadowMapUpdate function has a parameter to replace the
actual read operations with test reads. The only caller of
EFUSE_ShadowMapUpdate does not use this test mode.
Remove the read test code from EFUSE_ShadowMapUpdate and the low-level
functions that it calls.
Martin Kaiser [Sat, 13 Nov 2021 18:55:05 +0000 (19:55 +0100)]
staging: r8188eu: remove efuse type from read functions
Efuse_ReadAllMap, ReadEFuseByIC and ReadEFuse_Pseudo do not use their
efuseType parameter. Remove the parameter from these functions and
from their callers.
Sergio Paracuellos [Sat, 13 Nov 2021 19:20:44 +0000 (20:20 +0100)]
staging: mt7621-dma: remove driver from tree
This driver was a added a time ago and there is no special effort or work
to clean it and any progress at all to mainline it. Also, there is already
a driver from Mediatek in 'drivers/dma/mediatek/mtk-hsdma.c' which looks
pretty similar to this. So the way of supporting HSDMA for mt7621 would be
to modify that driver instead.
Sergio Paracuellos [Sat, 13 Nov 2021 19:20:43 +0000 (20:20 +0100)]
staging: ralink-gdma: remove driver from tree
This driver was a added a time ago and there is no special effort or work
to clean it and any progress at all to mainline it. Also, the main user of
this dma controller seems to be 'i2s' in mt7621 SoCs. There is no in-tree
driver at all for the 'i2s' and its related device tree node has also been
deleted from main device tree file. Hence, remove this driver also for
completeness.
Tommaso Merciai [Sat, 13 Nov 2021 10:21:20 +0000 (11:21 +0100)]
staging: vt6655: fix camelcase in bRadioOff
Replace camel case variable bRadioOff with snake case
variable radio_off.
Drop Hungarian notation prefix in `bRadioOff` variable.
Change it to use snake case.
Saurav Girepunje [Mon, 8 Nov 2021 04:11:22 +0000 (09:41 +0530)]
staging: rtl8192u: remove the if condition without effect
In function rtl8192_adapter_start priv->pFirmware->firmware_status
is assign to FW_STATUS_0_INIT just after assignment variable is
again get check for same value. Therefore if condition will be
always be true. So remove the if condition ,else if section and
else section which will never get execute.
Saurav Girepunje [Sun, 7 Nov 2021 18:08:30 +0000 (23:38 +0530)]
staging: rtl8723bs: core: avoid unnecessary if condition
In function rtw_lps_change_dtim_hdl remove the if condition check
to compare the pwrpriv->dtim to dtim . If both are not equal dtim
is getting assign to pwrpriv->dtim. But if both are equal assigning
dtim to pwrpriv->dtim will not make any difference on value. So remove
the unnecessary if condition check.
Saurav Girepunje [Sun, 7 Nov 2021 16:43:10 +0000 (22:13 +0530)]
staging: r8188eu: os_dep: Change the return type of function
Change the return type of rtw_init_default_value function
from u8 to void. This function always return success. This
is called from rtw_init_drv_sw where the return value from
this function is assign to local variable but the local variable
value is never checked. After change the return type to void
remove the local variable ret8 in rtw_init_drv_sw function.
Martin Kaiser [Sun, 7 Nov 2021 16:16:24 +0000 (17:16 +0100)]
staging: r8188eu: remove efuse write functions
The r8188eu driver in its current state does not need write access
to the efuses. Only read access is required to get the chip id, the
mac address and other settings.
This patch removes a lot of unused code for writing the efuses.
Sidong Yang [Sun, 7 Nov 2021 10:59:47 +0000 (10:59 +0000)]
staging: pi433: print rf69 debug message more detail
When pi433 failed for rf69 configuration, Debug message should help for
finding which value is incorrect. But it's hard to know because it just
prints "illegal value". This patch make print message more detail.
Phillip Potter [Sat, 6 Nov 2021 23:16:35 +0000 (23:16 +0000)]
staging: r8188eu: convert final two MSG_88E calls to netdev_dbg
Convert final two MSG_88E calls to use netdev_dbg instead. They seem to
contain useful information so rather than delete them outright, it makes
sense to convert them over to use the kernel's dynamic debugging/logging
facility as other network drivers do.
Tommaso Merciai [Sat, 6 Nov 2021 18:48:19 +0000 (19:48 +0100)]
staging: vt6655: fix camelcase byData in card.c
Replace camelcase variable "byData" into linux kernel coding style
equivalent variable "data" in card.c.
"by" prefix in hungarian notation stands for byte or unsigned char
Phillip Potter [Fri, 5 Nov 2021 00:28:07 +0000 (00:28 +0000)]
staging: r8188eu: remove MSG_88E call from odm_TXPowerTrackingThermalMeterInit
Remove unnecessary MSG_88E macro call from hal/odm.c, within the
function odm_TXPowerTrackingThermalMeterInit. All it does is print a
struct member, during initialization, that is then immediately set on
the following line. It is therefore surplus to requirements.
Saurav Girepunje [Wed, 3 Nov 2021 15:48:41 +0000 (21:18 +0530)]
staging: r8188eu: os_dep: remove the goto statement
Remove the goto statement from rtw_init_drv_sw(). In this function goto
can be replace by return statement. As on goto label exit, function
only return it is not performing any cleanup. Avoiding goto will
improve the function readability.
Gustavo A. R. Silva [Sun, 14 Nov 2021 00:57:25 +0000 (18:57 -0600)]
kconfig: Add support for -Wimplicit-fallthrough
Add Kconfig support for -Wimplicit-fallthrough for both GCC and Clang.
The compiler option is under configuration CC_IMPLICIT_FALLTHROUGH,
which is enabled by default.
Special thanks to Nathan Chancellor who fixed the Clang bug[1][2]. This
bugfix only appears in Clang 14.0.0, so older versions still contain
the bug and -Wimplicit-fallthrough won't be enabled for them, for now.
This concludes a long journey and now we are finally getting rid
of the unintentional fallthrough bug-class in the kernel, entirely. :)
Linus Torvalds [Sun, 14 Nov 2021 20:18:22 +0000 (12:18 -0800)]
Merge tag 'xfs-5.16-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs cleanups from Darrick Wong:
"The most 'exciting' aspect of this branch is that the xfsprogs
maintainer and I have worked through the last of the code
discrepancies between kernel and userspace libxfs such that there are
no code differences between the two except for #includes.
IOWs, diff suffices to demonstrate that the userspace tools behave the
same as the kernel, and kernel-only bits are clearly marked in the
/kernel/ source code instead of just the userspace source.
Summary:
- Clean up open-coded swap() calls.
- A little bit of #ifdef golf to complete the reunification of the
kernel and userspace libxfs source code"
* tag 'xfs-5.16-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: sync xfs_btree_split macros with userspace libxfs
xfs: #ifdef out perag code for userspace
xfs: use swap() to make dabtree code cleaner
Linus Torvalds [Sun, 14 Nov 2021 19:53:59 +0000 (11:53 -0800)]
Merge tag 'for-5.16/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull more parisc fixes from Helge Deller:
"Fix a build error in stracktrace.c, fix resolving of addresses to
function names in backtraces, fix single-stepping in assembly code and
flush userspace pte's when using set_pte_at()"
* tag 'for-5.16/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc/entry: fix trace test in syscall exit path
parisc: Flush kernel data mapping in set_pte_at() when installing pte for user page
parisc: Fix implicit declaration of function '__kernel_text_address'
parisc: Fix backtrace to always include init funtion names
Linus Torvalds [Sun, 14 Nov 2021 19:37:49 +0000 (11:37 -0800)]
Merge tag 'sh-for-5.16' of git://git.libc.org/linux-sh
Pull arch/sh updates from Rich Felker.
* tag 'sh-for-5.16' of git://git.libc.org/linux-sh:
sh: pgtable-3level: Fix cast to pointer from integer of different size
sh: fix READ/WRITE redefinition warnings
sh: define __BIG_ENDIAN for math-emu
sh: math-emu: drop unused functions
sh: fix kconfig unmet dependency warning for FRAME_POINTER
sh: Cleanup about SPARSE_IRQ
sh: kdump: add some attribute to function
maple: fix wrong return value of maple_bus_init().
sh: boot: avoid unneeded rebuilds under arch/sh/boot/compressed/
sh: boot: add intermediate vmlinux.bin* to targets instead of extra-y
sh: boards: Fix the cacography in irq.c
sh: check return code of request_irq
sh: fix trivial misannotations
Linus Torvalds [Sun, 14 Nov 2021 19:30:50 +0000 (11:30 -0800)]
Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King:
- Fix early_iounmap
- Drop cc-option fallbacks for architecture selection
* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 9156/1: drop cc-option fallbacks for architecture selection
ARM: 9155/1: fix early early_iounmap()
Linus Torvalds [Sun, 14 Nov 2021 19:11:51 +0000 (11:11 -0800)]
Merge tag 'devicetree-fixes-for-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree fixes from Rob Herring:
- Two fixes due to DT node name changes on Arm, Ltd. boards
- Treewide rename of Ingenic CGU headers
- Update ST email addresses
- Remove Netlogic DT bindings
- Dropping few more cases of redundant 'maxItems' in schemas
- Convert toshiba,tc358767 bridge binding to schema
* tag 'devicetree-fixes-for-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
dt-bindings: watchdog: sunxi: fix error in schema
bindings: media: venus: Drop redundant maxItems for power-domain-names
dt-bindings: Remove Netlogic bindings
clk: versatile: clk-icst: Ensure clock names are unique
of: Support using 'mask' in making device bus id
dt-bindings: treewide: Update @st.com email address to @foss.st.com
dt-bindings: media: Update maintainers for st,stm32-hwspinlock.yaml
dt-bindings: media: Update maintainers for st,stm32-cec.yaml
dt-bindings: mfd: timers: Update maintainers for st,stm32-timers
dt-bindings: timer: Update maintainers for st,stm32-timer
dt-bindings: i2c: imx: hardware do not restrict clock-frequency to only 100 and 400 kHz
dt-bindings: display: bridge: Convert toshiba,tc358767.txt to yaml
dt-bindings: Rename Ingenic CGU headers to ingenic,*.h
Linus Torvalds [Sun, 14 Nov 2021 18:43:38 +0000 (10:43 -0800)]
Merge tag 'timers-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
"A single fix for POSIX CPU timers to address a problem where POSIX CPU
timer delivery stops working for a new child task because
copy_process() copies state information which is only valid for the
parent task"
* tag 'timers-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Clear task::posix_cputimers_work in copy_process()
Linus Torvalds [Sun, 14 Nov 2021 18:38:27 +0000 (10:38 -0800)]
Merge tag 'irq-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"A set of fixes for the interrupt subsystem
Core code:
- A regression fix for the Open Firmware interrupt mapping code where
a interrupt controller property in a node caused a map property in
the same node to be ignored.
Interrupt chip drivers:
- Workaround a limitation in SiFive PLIC interrupt chip which
silently ignores an EOI when the interrupt line is masked.
- Provide the missing mask/unmask implementation for the CSKY MP
interrupt controller.
PCI/MSI:
- Prevent a use after free when PCI/MSI interrupts are released by
destroying the sysfs entries before freeing the memory which is
accessed in the sysfs show() function.
- Implement a mask quirk for the Nvidia ION AHCI chip which does not
advertise masking capability despite implementing it. Even worse
the chip comes out of reset with all MSI entries masked, which due
to the missing masking capability never get unmasked.
- Move the check which prevents accessing the MSI[X] masking for XEN
back into the low level accessors. The recent consolidation missed
that these accessors can be invoked from places which do not have
that check which broke XEN. Move them back to he original place
instead of sprinkling tons of these checks all over the code"
* tag 'irq-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
of/irq: Don't ignore interrupt-controller when interrupt-map failed
irqchip/sifive-plic: Fixup EOI failed when masked
irqchip/csky-mpintc: Fixup mask/unmask implementation
PCI/MSI: Destroy sysfs before freeing entries
PCI: Add MSI masking quirk for Nvidia ION AHCI
PCI/MSI: Deal with devices lying about their MSI mask capability
PCI/MSI: Move non-mask check back into low level accessors
Linus Torvalds [Sun, 14 Nov 2021 18:30:17 +0000 (10:30 -0800)]
Merge tag 'locking-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 static call update from Thomas Gleixner:
"A single fix for static calls to make the trampoline patching more
robust by placing explicit signature bytes after the call trampoline
to prevent patching random other jumps like the CFI jump table
entries"
* tag 'locking-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
static_call,x86: Robustify trampoline patching
Linus Torvalds [Sun, 14 Nov 2021 17:39:03 +0000 (09:39 -0800)]
Merge tag 'sched_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Borislav Petkov:
- Avoid touching ~100 config files in order to be able to select the
preemption model
- clear cluster CPU masks too, on the CPU unplug path
- prevent use-after-free in cfs
- Prevent a race condition when updating CPU cache domains
- Factor out common shared part of smp_prepare_cpus() into a common
helper which can be called by both baremetal and Xen, in order to fix
a booting of Xen PV guests
* tag 'sched_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
preempt: Restore preemption model selection configs
arch_topology: Fix missing clear cluster_cpumask in remove_cpu_topology()
sched/fair: Prevent dead task groups from regaining cfs_rq's
sched/core: Mitigate race cpus_share_cache()/update_top_cache_domain()
x86/smp: Factor out parts of native_smp_prepare_cpus()
Linus Torvalds [Sun, 14 Nov 2021 17:33:12 +0000 (09:33 -0800)]
Merge tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
- Prevent unintentional page sharing by checking whether a page
reference to a PMU samples page has been acquired properly before
that
- Make sure the LBR_SELECT MSR is saved/restored too
- Reset the LBR_SELECT MSR when resetting the LBR PMU to clear any
residual data left
* tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Avoid put_page() when GUP fails
perf/x86/vlbr: Add c->flags to vlbr event constraints
perf/x86/lbr: Reset LBR_SELECT during vlbr reset
Linus Torvalds [Sun, 14 Nov 2021 17:29:03 +0000 (09:29 -0800)]
Merge tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Add the model number of a new, Raptor Lake CPU, to intel-family.h
- Do not log spurious corrected MCEs on SKL too, due to an erratum
- Clarify the path of paravirt ops patches upstream
- Add an optimization to avoid writing out AMX components to sigframes
when former are in init state
* tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Add Raptor Lake to Intel family
x86/mce: Add errata workaround for Skylake SKX37
MAINTAINERS: Add some information to PARAVIRT_OPS entry
x86/fpu: Optimize out sigframe xfeatures when in init state
Linus Torvalds [Sun, 14 Nov 2021 17:25:01 +0000 (09:25 -0800)]
Merge tag 'perf-tools-for-v5.16-2021-11-13' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Pull more perf tools updates from Arnaldo Carvalho de Melo:
"Hardware tracing:
- ARM:
* Print the size of the buffer size consistently in hexadecimal in
ARM Coresight.
* Add Coresight snapshot mode support.
* Update --switch-events docs in 'perf record'.
* Support hardware-based PID tracing.
* Track task context switch for cpu-mode events.
- Fix memory leak of perf_cpu_map__new() in the futex benchmarks.
libbpf:
- Add some more weak libbpf functions o allow building with the
libbpf versions, old ones, present in distros.
libbeauty:
- Translate [gs]setsockopt 'level' argument integer values to
strings.
tools headers UAPI:
- Sync futex_waitv, arch prctl, sound, i195_drm and msr-index files
with the kernel sources.
Documentation:
- Add documentation to 'struct symbol'.
- Synchronize the definition of enum perf_hw_id with code in
tools/perf/design.txt"
* tag 'perf-tools-for-v5.16-2021-11-13' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (67 commits)
perf tests: Remove bash constructs from stat_all_pmu.sh
perf tests: Remove bash construct from record+zstd_comp_decomp.sh
perf test: Remove bash construct from stat_bpf_counters.sh test
perf bench futex: Fix memory leak of perf_cpu_map__new()
tools arch x86: Sync the msr-index.h copy with the kernel sources
tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
tools headers UAPI: Sync sound/asound.h with the kernel sources
tools headers UAPI: Sync linux/prctl.h with the kernel sources
tools headers UAPI: Sync arch prctl headers with the kernel sources
perf tools: Add more weak libbpf functions
perf bpf: Avoid memory leak from perf_env__insert_btf()
perf symbols: Factor out annotation init/exit
perf symbols: Bit pack to save a byte
perf symbols: Add documentation to 'struct symbol'
tools headers UAPI: Sync files changed by new futex_waitv syscall
perf test bpf: Use ARRAY_CHECK() instead of ad-hoc equivalent, addressing array_size.cocci warning
perf arm-spe: Support hardware-based PID tracing
perf arm-spe: Save context ID in record
perf arm-spe: Update --switch-events docs in 'perf record'
perf arm-spe: Track task context switch for cpu-mode events
...
Linus Torvalds [Sat, 13 Nov 2021 23:32:30 +0000 (15:32 -0800)]
Merge tag 'zstd-for-linus-v5.16' of git://github.com/terrelln/linux
Pull zstd update from Nick Terrell:
"Update to zstd-1.4.10.
Add myself as the maintainer of zstd and update the zstd version in
the kernel, which is now 4 years out of date, to a much more recent
zstd release. This includes bug fixes, much more extensive fuzzing,
and performance improvements. And generates the kernel zstd
automatically from upstream zstd, so it is easier to keep the zstd
verison up to date, and we don't fall so far out of date again.
This includes 5 commits that update the zstd library version:
- Adds a new kernel-style wrapper around zstd.
This wrapper API is functionally equivalent to the subset of the
current zstd API that is currently used. The wrapper API changes to
be kernel style so that the symbols don't collide with zstd's
symbols. The update to zstd-1.4.10 maintains the same API and
preserves the semantics, so that none of the callers need to be
updated. All callers are updated in the commit, because there are
zero functional changes.
- Adds an indirection for `lib/decompress_unzstd.c` so it doesn't
depend on the layout of `lib/zstd/` to include every source file.
This allows the next patch to be automatically generated.
- Imports the zstd-1.4.10 source code. This commit is automatically
generated from upstream zstd (https://github.com/facebook/zstd).
- Adds me (terrelln@fb.com) as the maintainer of `lib/zstd`.
- Fixes a newly added build warning for clang.
The discussion around this patchset has been pretty long, so I've
included a FAQ-style summary of the history of the patchset, and why
we are taking this approach.
Why do we need to update?
-------------------------
The zstd version in the kernel is based off of zstd-1.3.1, which is
was released August 20, 2017. Since then zstd has seen many bug fixes
and performance improvements. And, importantly, upstream zstd is
continuously fuzzed by OSS-Fuzz, and bug fixes aren't backported to
older versions. So the only way to sanely get these fixes is to keep
up to date with upstream zstd.
There are no known security issues that affect the kernel, but we need
to be able to update in case there are. And while there are no known
security issues, there are relevant bug fixes. For example the problem
with large kernel decompression has been fixed upstream for over 2
years [1]
Additionally the performance improvements for kernel use cases are
significant. Measured for x86_64 on my Intel i9-9900k @ 3.6 GHz:
- BtrFS zstd compression at levels 1 and 3 is 5% faster
- BtrFS zstd decompression+read is 15% faster
- SquashFS zstd decompression+read is 15% faster
- F2FS zstd compression+write at level 3 is 8% faster
- F2FS zstd decompression+read is 20% faster
- ZRAM decompression+read is 30% faster
- Kernel zstd decompression is 35% faster
- Initramfs zstd decompression+build is 5% faster
On top of this, there are significant performance improvements coming
down the line in the next zstd release, and the new automated update
patch generation will allow us to pull them easily.
How is the update patch generated?
----------------------------------
The first two patches are preparation for updating the zstd version.
Then the 3rd patch in the series imports upstream zstd into the
kernel. This patch is automatically generated from upstream. A script
makes the necessary changes and imports it into the kernel. The
changes are:
- Replace all libc dependencies with kernel replacements and rewrite
includes.
This automation gets tested every commit by upstream's continuous
integration. When we cut a new zstd release, we will submit a patch to
the kernel to update the zstd version in the kernel.
The automated process makes it easy to keep the kernel version of zstd
up to date. The current zstd in the kernel shares the guts of the
code, but has a lot of API and minor changes to work in the kernel.
This is because at the time upstream zstd was not ready to be used in
the kernel envrionment as-is. But, since then upstream zstd has
evolved to support being used in the kernel as-is.
Why are we updating in one big patch?
-------------------------------------
The 3rd patch in the series is very large. This is because it is
restructuring the code, so it both deletes the existing zstd, and
re-adds the new structure. Future updates will be directly
proportional to the changes in upstream zstd since the last import.
They will admittidly be large, as zstd is an actively developed
project, and has hundreds of commits between every release. However,
there is no other great alternative.
One option ruled out is to replay every upstream zstd commit. This is
not feasible for several reasons:
- There are over 3500 upstream commits since the zstd version in the
kernel.
- The automation to automatically generate the kernel update was only
added recently, so older commits cannot easily be imported.
- Not every upstream zstd commit builds.
- Only zstd releases are "supported", and individual commits may have
bugs that were fixed before a release.
Another option to reduce the patch size would be to first reorganize
to the new file structure, and then apply the patch. However, the
current kernel zstd is formatted with clang-format to be more
"kernel-like". But, the new method imports zstd as-is, without
additional formatting, to allow for closer correlation with upstream,
and easier debugging. So the patch wouldn't be any smaller.
It also doesn't make sense to import upstream zstd commit by commit
going forward. Upstream zstd doesn't support production use cases
running of the development branch. We have a lot of post-commit
fuzzing that catches many bugs, so indiviudal commits may be buggy,
but fixed before a release. So going forward, I intend to import every
(important) zstd release into the Kernel.
So, while it isn't ideal, updating in one big patch is the only patch
I see forward.
Who is responsible for this code?
---------------------------------
I am. This patchset adds me as the maintainer for zstd. Previously,
there was no tree for zstd patches. Because of that, there were
several patches that either got ignored, or took a long time to merge,
since it wasn't clear which tree should pick them up. I'm officially
stepping up as maintainer, and setting up my tree as the path through
which zstd patches get merged. I'll make sure that patches to the
kernel zstd get ported upstream, so they aren't erased when the next
version update happens.
How is this code tested?
------------------------
I tested every caller of zstd on x86_64 (BtrFS, ZRAM, SquashFS, F2FS,
Kernel, InitRAMFS). I also tested Kernel & InitRAMFS on i386 and
aarch64. I checked both performance and correctness.
Also, thanks to many people in the community who have tested these
patches locally.
Lastly, this code will bake in linux-next before being merged into
v5.16.
Why update to zstd-1.4.10 when zstd-1.5.0 has been released?
------------------------------------------------------------
This patchset has been outstanding since 2020, and zstd-1.4.10 was the
latest release when it was created. Since the update patch is
automatically generated from upstream, I could generate it from
zstd-1.5.0.
However, there were some large stack usage regressions in zstd-1.5.0,
and are only fixed in the latest development branch. And the latest
development branch contains some new code that needs to bake in the
fuzzer before I would feel comfortable releasing to the kernel.
Once this patchset has been merged, and we've released zstd-1.5.1, we
can update the kernel to zstd-1.5.1, and exercise the update process.
You may notice that zstd-1.4.10 doesn't exist upstream. This release
is an artifical release based off of zstd-1.4.9, with some fixes for
the kernel backported from the development branch. I will tag the
zstd-1.4.10 release after this patchset is merged, so the Linux Kernel
is running a known version of zstd that can be debugged upstream.
Why was a wrapper API added?
----------------------------
The first versions of this patchset migrated the kernel to the
upstream zstd API. It first added a shim API that supported the new
upstream API with the old code, then updated callers to use the new
shim API, then transitioned to the new code and deleted the shim API.
However, Cristoph Hellwig suggested that we transition to a kernel
style API, and hide zstd's upstream API behind that. This is because
zstd's upstream API is supports many other use cases, and does not
follow the kernel style guide, while the kernel API is focused on the
kernel's use cases, and follows the kernel style guide.
Where is the previous discussion?
---------------------------------
Links for the discussions of the previous versions of the patch set
below. The largest changes in the design of the patchset are driven by
the discussions in v11, v5, and v1. Sorry for the mix of links, I
couldn't find most of the the threads on lkml.org"
Linus Torvalds [Sat, 13 Nov 2021 21:14:05 +0000 (13:14 -0800)]
Merge tag 'virtio-mem-for-5.16' of git://github.com/davidhildenbrand/linux
Pull virtio-mem update from David Hildenbrand:
"Support the VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE feature in virtio-mem,
now that "accidential" access to logically unplugged memory inside
added Linux memory blocks is no longer possible, because we:
- Removed /dev/kmem in commit bbcd53c96071 ("drivers/char: remove
/dev/kmem for good")
- Disallowed access to virtio-mem device memory via /dev/mem in
commit 2128f4e21aa ("virtio-mem: disallow mapping virtio-mem memory
via /dev/mem")
- Sanitized access to virtio-mem device memory via /proc/kcore in
commit 0daa322b8ff9 ("fs/proc/kcore: don't read offline sections,
logically offline pages and hwpoisoned pages")
- Sanitized access to virtio-mem device memory via /proc/vmcore in
commit ce2814622e84 ("virtio-mem: kdump mode to sanitize
/proc/vmcore access")
The new VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE feature that will be
required by some hypervisors implementing virtio-mem in the near
future, so let's support it now that we safely can"
* tag 'virtio-mem-for-5.16' of git://github.com/davidhildenbrand/linux:
virtio-mem: support VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE
Changing the regexes to a grep works in sh and prints this:
$ ./perf test -v 90
90: perf all PMU test :
--- start ---
test child forked, pid 60186
[...]
Testing tlb_flush.stlb_any
test child finished with 0
---- end ----
perf all PMU test: Ok
Signed-off-by: James Clark <james.clark@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Yonghong Song <yhs@fb.com> Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20211028134828.65774-4-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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