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Fix sparse warnings by marking these structures static.
Fixes: 273bc890a2a8 ("cpufreq: tegra194: Add support for Tegra234")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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The sys_clk frequency is 165.625MHz. The register reference of the
Generic Clock controller lists the CPU clock as 600MHz, the DDR clock as
300MHz and the SYS clock as 162.5MHz. This is wrong. It was first
noticed during the fan driver development and it was measured and
verified via the CLK_MON output of the SoC which can be configured to
output sys_clk/64.
The core PLL settings (which drives the SYS clock) seems to be as
follows:
DIVF = 52
DIVQ = 3
DIVR = 1
With a refernce clock of 25MHz, this means we have a post divider clock
Fpfd = Fref / (DIVR + 1) = 25MHz / (1 + 1) = 12.5MHz
The resulting VCO frequency is then
Fvco = Fpfd * (DIVF + 1) * 2 = 12.5MHz * (52 + 1) * 2 = 1325MHz
And the output frequency is
Fout = Fvco / 2^DIVQ = 1325MHz / 2^3 = 165.625Mhz
This all adds up to the constrains of the PLL:
10MHz <= Fpfd <= 200MHz
20MHz <= Fout <= 1000MHz
1000MHz <= Fvco <= 2000MHz
Fixes: 290deaa10c50 ("ARM: dts: add DT for lan966 SoC and 2-port board pcb8291")
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220326194028.2945985-1-michael@walle.cc
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There is no need to EXPORT the functions hwa742_update_window_async()
and omapfb_update_window_async() since they are not used anywhere inside
or outside the kernel tree.
Signed-off-by: Helge Deller <deller@gmx.de>
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As of v2.1.0, falcon_decode_var() contains a quirk to fix a rounding
error, as explained by Günther Kelleter on Fri, 30 Aug 1996:
This diff removes the now obsolete Falcon video option "pwrsave", and
fixes a rounding error that is triggered by the resolution switching X
server (those who use the pixel clock value 39722 in their /etc/fb.modes
should change it to 39721).
However, this causes the modified video mode returned by
falcon_decode_var() to not match the video mode returned by
falcon_encode_var(). Fix this by dropping the quirk.
Unfortunately /etc/fb.modes in fbset was never updated, so the
"640x480-60" mode still contains the wrong pixclock.
Hence this change may introduce a regression.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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Several definitions and variables are unused.
Some variables are set but further unused.
Remove them.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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The pixclock values in the vga and vga70 modes are wrong, as they should
use the 25.175 MHz clock instead of the 32 MHz clock.
Swap the left and right margins to match f25.{right,left} (struct
pixel_clock declares them in a different order), and update the hsync
lengths to match what the driver programs by default.
Correct the (wrong) floating-point vrefresh value for the vga mode.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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The vertical refresh rate for the TT High video mode (1280x960) is
wrong. Fortunately this field is not really used.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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Arbitrary pointers can be passed to functions accepting "void *" without
casting.
Remove the casts, as they make it impossible to validate types.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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There is no need to cast fb_info.par to "struct atafb_par *", as the
former has type "void *".
Remove the casts, as they make it impossible to validate types.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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The red, green, and blue color values are 16-bit, while the external
graphics hardware registers are 8-bit.
Add the missing conversion from 16-bit to 8-bit.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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Currently, the "inverse" option does not do anything, as it just sets a
flag, which is further unused.
Fix this by calling fb_invert_cmaps() instead, like other drivers do.
As this only affects the console colormap, this does not affect X.
Update the documentation to match the actual behavior.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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Vertical wrap is not supported (fb_fix_screeninfo.ywrapstep = 0), hence
there is no point in setting the FB_VMODE_YWRAP flag in video modes.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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The fb_pan_display() function in the core already takes care of
validating the panning parameters before calling the driver's
.fb_pan_display() callback, and of updating the panning state
afterwards, so there is no need to repeat that in the driver.
Remove the duplicate code.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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The various *fb_setup() and *fb_init() functions are only used locally,
so they should be static. Most of them do not need forward
declarations, so remove these where appropriate.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Helge Deller <deller@gmx.de>
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cirrusfb_zorro_unregister() is only used locally, hence make it static.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Helge Deller <deller@gmx.de>
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sa1100fb_setup() has been unused since the beginning of Linux git
history.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Helge Deller <deller@gmx.de>
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The fb_pan_display() function in the core already takes care of
validating most panning parameters before calling the driver's
.fb_pan_display() callback, and of updating the panning state
afterwards, so there is no need to repeat that in the driver.
Remove the duplicate code.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Helge Deller <deller@gmx.de>
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No need to expose this structure definition in the header.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Free slots tracking assumes that slots in a segment can be allocated to
fulfill a request. This implies that slots in a segment should belong to
the same area. Although the possibility of a violation is low, it is better
to explicitly enforce segments won't span multiple areas by adjusting the
number of slabs when configuring areas.
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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default_nslabs are rounded up in two cases with exactly same comments.
Add a simple wrapper to reduce duplicate code/comments. It is preparatory
to adding more logics into the round-up.
No functional change intended.
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Commit 20347fca71a3 ("swiotlb: split up the global swiotlb lock") splits
io_tlb_mem into multiple areas. Each area has its own lock and index. The
global ones are not used so remove them.
Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Don't dereference "mem" after it has been freed. Flip the
two kfree()s around to address this bug.
Fixes: 26ffb91fa5e0 ("swiotlb: split up the global swiotlb lock")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Add compatible for EPSS CPUFREQ-HW on SM6375.
Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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msm8939 will uses this driver instead of the generic dt-cpufreq. Add to the
compatible list.
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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A number of devices listed in drivers/cpufreq/qcom-cpufreq-nvmem.c appear
to be missing from the compatible list.
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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Adding missing compat entries to the cpufreq node
Documentation/devicetree/bindings/cpufreq/qcom-cpufreq-nvmem.yaml shows up
a dt_binding_check in this file.
opp-v2-kryo-cpu.example.dtb: /: cpus:cpu@0: 'power-domains' is a required property
opp-v2-kryo-cpu.example.dtb: /: cpus:cpu@0: 'power-domain-names' is a required property
opp-v2-kryo-cpu.example.dtb: /: opp-table-0:opp-307200000: 'required-opps' is a required property
Fixes: ec24d1d55469 ("dt-bindings: opp: Convert qcom-nvmem-cpufreq to DT schema")
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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From a state where all policy->related_cpus are offline, putting one
of the policy's CPU back online re-activates the policy by:
1. Calling cpufreq_driver->online()
2. Setting the CPU in policy->cpus
qcom_cpufreq_hw_cpu_online() makes use of policy->cpus. Thus 1. and 2.
should be inverted to avoid having a policy->cpus empty. The
qcom-cpufreq-hw is the only driver affected by this.
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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Details is added about "caps" attribute group in the ABI documentation.
This is used to expose some of the PMU attributes in "caps"
directory under : /sys/bus/event_source/devices/<dev>/. The dev/caps
will contain information about features that platform specific PMU
supports.
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220520084630.15181-2-atrajeev@linux.vnet.ibm.com
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Add caps support under "/sys/bus/event_source/devices/<pmu>/"
for powerpc. This directory can be used to expose some of the
specific features that powerpc PMU supports to the user.
Example: pmu_name. The name of PMU registered will depend on
platform, say power9 or power10 or it could be Generic Compat
PMU.
Currently the only way to know which is the registered
PMU is from the dmesg logs. But clearing the dmesg will make it
difficult to know exact PMU backend used. And even extracting
from dmesg will be complicated, as we need to parse the dmesg
logs and add filters for pmu name. Whereas by exposing it via
caps will make it easy as we just need to directly read it from
the sysfs.
Add a caps directory to /sys/bus/event_source/devices/cpu/
for power8, power9, power10 and generic compat PMU in respective
PMU driver code. Update the pmu_name file under caps folder
in core-book3s using "attr_update".
The information exposed currently:
- pmu_name : Underlying PMU name from the driver
Example result with power9 pmu:
# ls /sys/bus/event_source/devices/cpu/caps
pmu_name
# cat /sys/bus/event_source/devices/cpu/caps/pmu_name
POWER9
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220520084630.15181-1-atrajeev@linux.vnet.ibm.com
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When booting on a machine that uses the compat pmu driver we see this:
[ 0.071192] GENERIC_COMPAT performance monitor hardware support registered
Which is a bit shouty. Give it a nicer name.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220610044006.2095806-1-joel@jms.id.au
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Fix spelling typo in comment.
Link: https://lkml.kernel.org/r/20220715060035.632903-1-13667453960@163.com
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Reported-by: k2ci <kernel-bot@kylinos.cn>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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kernel test robot throws below warning ->
arch/ia64/include/asm/mmu_context.h: In function 'reload_context':
arch/ia64/include/asm/mmu_context.h:127:48: warning: variable
'old_rr4' set but not used [-Wunused-but-set-variable]
127 | unsigned long rr0, rr1, rr2, rr3, rr4, old_rr4;
Add it under CONFIG_HUGETLB_PAGE
Link: https://lkml.kernel.org/r/20220626022114.4020-1-jrdr.linux@gmail.com
Signed-off-by: Souptick Joarder (HPE) <jrdr.linux@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Booting with vsyscall=xonly results in the following vsyscall VMA:
ffffffffff600000-ffffffffff601000 --xp ... [vsyscall]
Test does read from fixed vsyscall address to determine if kernel
supports vsyscall page but it doesn't work because, well, vsyscall
page is execute only.
Fix test by trying to execute from the first byte of the page which
contains gettimeofday() stub. This should work because vsyscall
entry points have stable addresses by design.
Alexey, avoiding parsing .config, /proc/config.gz and
/proc/cmdline at all costs.
Link: https://lkml.kernel.org/r/Ys2KgeiEMboU8Ytu@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: <dylanbhatch@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Commit 7bc3e6e55acf06 ("proc: Use a list of inodes to flush from proc")
moved proc_flush_task() behind __exit_signal(). Then, process systemd can
take long period high cpu usage during releasing task in following
concurrent processes:
systemd ps
kernel_waitid stat(/proc/tgid)
do_wait filename_lookup
wait_consider_task lookup_fast
release_task
__exit_signal
__unhash_process
detach_pid
__change_pid // remove task->pid_links
d_revalidate -> pid_revalidate // 0
d_invalidate(/proc/tgid)
shrink_dcache_parent(/proc/tgid)
d_walk(/proc/tgid)
spin_lock_nested(/proc/tgid/fd)
// iterating opened fd
proc_flush_pid |
d_invalidate (/proc/tgid/fd) |
shrink_dcache_parent(/proc/tgid/fd) |
shrink_dentry_list(subdirs) ↓
shrink_lock_dentry(/proc/tgid/fd) --> race on dentry lock
Function d_invalidate() will remove dentry from hash firstly, but why does
proc_flush_pid() process dentry '/proc/tgid/fd' before dentry
'/proc/tgid'? That's because proc_pid_make_inode() adds proc inode in
reverse order by invoking hlist_add_head_rcu(). But proc should not add
any inodes under '/proc/tgid' except '/proc/tgid/task/pid', fix it by
adding inode into 'pid->inodes' only if the inode is /proc/tgid or
/proc/tgid/task/pid.
Performance regression:
Create 200 tasks, each task open one file for 50,000 times. Kill all
tasks when opened files exceed 10,000,000 (cat /proc/sys/fs/file-nr).
Before fix:
$ time killall -wq aa
real 4m40.946s # During this period, we can see 'ps' and 'systemd'
taking high cpu usage.
After fix:
$ time killall -wq aa
real 1m20.732s # During this period, we can see 'systemd' taking
high cpu usage.
Link: https://lkml.kernel.org/r/20220713130029.4133533-1-chengzhihao1@huawei.com
Fixes: 7bc3e6e55acf06 ("proc: Use a list of inodes to flush from proc")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216054
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Suggested-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Remove the unused inode field of the autofs dentry info structure.
Link: https://lkml.kernel.org/r/165724460393.30914.6511330213821246793.stgit@donald.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The function autofs_mountpoint_changed() is unusual, add a comment about
two cases for which it is needed.
Link: https://lkml.kernel.org/r/165724459804.30914.10974834416046555127.stgit@donald.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The dentry info. field count is used to check if a dentry is in use
during expire. But, to be used for this the count field must account for
the presence of child dentries in a directory dentry.
Therefore it can also be used to check for an empty directory dentry which
can be done without having to to take an additional lock or account for
the presence of a readdir cursor dentry as is done by simple_empty().
Link: https://lkml.kernel.org/r/165724459238.30914.1504611159945950108.stgit@donald.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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If an autofs dentry is a mount root directory there's no ->mkdir() call to
set its count to one.
To make the dentry info count consistent for all autofs dentries set count
to one when the dentry info struct is allocated.
Link: https://lkml.kernel.org/r/165724458671.30914.2902424437132835325.stgit@donald.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "autofs: misc patches".
This series contains several patches that resulted mostly from comments
made by Al Viro (quite a long time ago now).
This patch (of 5):
Eliminate some code duplication from mkdir/rmdir/symlink/unlink methods by
using the inode operation .permission().
Link: https://lkml.kernel.org/r/165724445154.30914.10970894936827635879.stgit@donald.themaw.net
Link: https://lkml.kernel.org/r/165724458096.30914.13499431569758625806.stgit@donald.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Allocate device resource from local node memory when the numa locality of
the device is specified.
Link: https://lkml.kernel.org/r/20220708131952.14500-1-mark-pk.tsai@mediatek.com
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently instrumentation_end() won't be called if printk_ratelimit()
returned false.
Link: https://lkml.kernel.org/r/a636d8e0-ad32-5888-acac-671f7f553bb3@I-love.SAKURA.ne.jp
Fixes: 126f21f0e8d46e2c ("lib/smp_processor_id: Move it into noinstr section")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The extern specifier is not needed for this declaration, so drop it. The
function also depends only on the input parameters, and has no side
effects, so it can be marked __pure like other functions in cpumask.h.
Link: https://lkml.kernel.org/r/72ab755695b74bb5fbaa756ae4c0edd708d172f1.1656777646.git.sander@svanheule.net
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Add a basic suite of tests for cpumask, providing some tests for empty and
completely filled cpumasks.
Link: https://lkml.kernel.org/r/c96980ec35c3bd23f17c3374bf42c22971545e85.1656777646.git.sander@svanheule.net
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Yury Norov <yury.norov@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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On uniprocessor builds, any CPU mask is assumed to contain exactly one CPU
(cpu0). This assumption ignores the existence of empty masks, resulting
in incorrect behaviour.
cpumask_first_zero(), cpumask_next_zero(), and for_each_cpu_not() don't
provide behaviour matching the assumption that a UP mask is always "1",
and instead provide behaviour matching the empty mask.
Drop the incorrectly optimised code and use the generic implementations in
all cases.
Link: https://lkml.kernel.org/r/86bf3f005abba2d92120ddd0809235cab4f759a6.1656777646.git.sander@svanheule.net
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Suggested-by: Yury Norov <yury.norov@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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On uniprocessor builds, the following loops will always run over a mask
that contains one enabled CPU (cpu0):
- for_each_possible_cpu
- for_each_online_cpu
- for_each_present_cpu
Provide uniprocessor-specific macros for these loops, that always run
exactly once.
Link: https://lkml.kernel.org/r/3a92869b902a075b97be5d1452c9c6badbbff0df.1656777646.git.sander@svanheule.net
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Acked-by: Yury Norov <yury.norov@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "cpumask: Fix invalid uniprocessor assumptions", v4.
On uniprocessor builds, it is currently assumed that any cpumask will
contain the single CPU: cpu0. This assumption is used to provide
optimised implementations.
The current assumption also appears to be wrong, by ignoring the fact that
users can provide empty cpumasks. This can result in bugs as explained in
[1] - for_each_cpu() will run one iteration of the loop even when passed
an empty cpumask.
This series introduces some basic tests, and updates the optimisations for
uniprocessor builds.
The x86 patch was written after the kernel test robot [2] ran into a
failed build. I have tried to list the files potentially affected by the
changes to cpumask.h, in an attempt to find any other cases that fail on
!SMP. I've gone through some of the files manually, and ran a few cross
builds, but nothing else popped up. I (build) checked about half of the
potientally affected files, but I do not have the resources to do them
all. I hope we can fix other issues if/when they pop up later.
[1] https://lore.kernel.org/all/20220530082552.46113-1-sander@svanheule.net/
[2] https://lore.kernel.org/all/202206060858.wA0FOzRy-lkp@intel.com/
This patch (of 5):
The maps to keep track of shared caches between CPUs on SMP systems are
declared in asm/smp.h, among them specifically cpu_llc_shared_map. These
maps are externally defined in cpu/smpboot.c. The latter is only compiled
on CONFIG_SMP=y, which means the declared extern symbols from asm/smp.h do
not have a corresponding definition on uniprocessor builds.
The inline cpu_llc_shared_mask() function from asm/smp.h refers to the map
declaration mentioned above. This function is referenced in cacheinfo.c
inside for_each_cpu() loop macros, to provide cpumask for the loop. On
uniprocessor builds, the symbol for the cpu_llc_shared_map does not exist.
However, the current implementation of for_each_cpu() also (wrongly)
ignores the provided mask.
By sheer luck, the compiler thus optimises out this unused reference to
cpu_llc_shared_map, and the linker therefore does not require the
cpu_llc_shared_mask to actually exist on uniprocessor builds. Only on SMP
bulids does smpboot.o exist to provide the required symbols.
To no longer rely on compiler optimisations for successful uniprocessor
builds, move the definitions of cpu_llc_shared_map and cpu_l2c_shared_map
from smpboot.c to cacheinfo.c.
Link: https://lkml.kernel.org/r/cover.1656777646.git.sander@svanheule.net
Link: https://lkml.kernel.org/r/e8167ddb570f56744a3dc12c2149a660a324d969.1656777646.git.sander@svanheule.net
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Marco Elver <elver@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When doing cross platform development on a machine sometimes it might be
useful to invoke bloat-o-meter for files which haven't been build with the
native toolchain. In cases when the host nm doesn't support the target
one then a toolchain-specific nm could be used. Add this ability by
adding the -p allowing invocations as:
./scripts/bloat-o-meter -p riscv64-unknown-linux-gnu- file1.o file2.o
Link: https://lkml.kernel.org/r/20220701113513.1938008-2-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This will facilitate further extension to the arguments the script takes.
As an added benefit it also produces saner usage output, where mutual
exclusivity of the c|d|t parameters is clearly visible:
./scripts/bloat-o-meter -h
usage: bloat-o-meter [-h] [-c | -d | -t] file1 file2
Simple script used to compare the symbol sizes of 2 object files
positional arguments:
file1 First file to compare
file2 Second file to compare
optional arguments:
-h, --help show this help message and exit
-c categorize output based on symbol type
-d Show delta of Data Section
-t Show delta of text Section
Link: https://lkml.kernel.org/r/20220701113513.1938008-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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If a process is killed or otherwise exits while having active network
connections and many threads waiting on epoll_wait, the threads will all
be woken immediately, but not removed from ep->wq. Then when network
traffic scans ep->wq in wake_up, every wakeup attempt will fail, and will
not remove the entries from the list.
This means that the cost of the wakeup attempt is far higher than usual,
does not decrease, and this also competes with the dying threads trying to
actually make progress and remove themselves from the wq.
Handle this by removing visited epoll wq entries unconditionally, rather
than only when the wakeup succeeds - the structure of ep_poll means that
the only potential loss is the timed_out->eavail heuristic, which now can
race and result in a redundant ep_send_events attempt. (But only when
incoming data and a timeout actually race, not on every timeout)
Shakeel added:
: We are seeing this issue in production with real workloads and it has
: caused hard lockups. Particularly network heavy workloads with a lot
: of threads in epoll_wait() can easily trigger this issue if they get
: killed (oom-killed in our case).
Link: https://lkml.kernel.org/r/xm26fsjotqda.fsf@google.com
Signed-off-by: Ben Segall <bsegall@google.com>
Tested-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Roman Penyaev <rpenyaev@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Khazhismel Kumykov <khazhy@google.com>
Cc: Heiher <r@hev.cc>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Remove unnecessary void* type casting.
Link: https://lkml.kernel.org/r/20220628021251.17197-1-yuzhe@nfschina.com
Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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