1583 Commits

Author SHA1 Message Date
Wang Qing
c5c1c700e2 doc: admin-guide: remove explanation of "watchdog/%u"
"watchdog/%u" threads has be replaced by cpu_stop_work,
which will mislead the reader.

Signed-off-by: Wang Qing <wangqing@vivo.com>
Link: https://lore.kernel.org/r/1615801744-31548-1-git-send-email-wangqing@vivo.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 14:32:02 -06:00
Mark O'Donovan
abb9c07885 Documentation: Add leading slash to some paths
Change multiple sys/xyz to /sys/xyz

Signed-off-by: Mark O'Donovan <shiftee@posteo.net>
Link: https://lore.kernel.org/r/20210328152837.73347-1-shiftee@posteo.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:49:19 -06:00
Thorsten Leemhuis
58c539453b docs: reporting-issues: reduce quoting and assorted fixes
A pile of small fixes:

- don't quote terms like vanilla, mainline, and stable, unless in they
  occur in places where readers new to the kernel might see them for the
  first time

- make people rule out that vendor patches are interfering if they face
  a regression in a stable or longterm kernel they saw in a vendor
  kernel for the first time

- s/bugs/issues/ in a selected spots

- exchange two headlines that got mixed up somehow

- add a few links to some of the steps in the guide

- Greg mentioned sending reports to the stable mailing list is
  sufficient, so remove the "CC stable maintainers" bits

- fix a few typos and mistakes in the text, with a few very small
  improvements along the way

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/07bca15d8465b8e234537feb8841dd2ff20243bc.1617113469.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:47:07 -06:00
Thorsten Leemhuis
4d2f46a8cd docs: reporting-issues.rst: reshuffle and improve TLDR
Make the TLDR a bit shorter while improving it at the same time by going
straight to the aspects readers are more interested it. The change makes
the process especially more straight-forward for people that hit a
regression in a stable or longterm kernel. Due to the changes the TLDR
now also matches the step by step guide better.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/762ccd7735315d2fdaa79612fccc1f474881118b.1617113469.git.linux@leemhuis.info
[ jc: fixed transposed _` as noted by Thorsten ]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:46:33 -06:00
Thorsten Leemhuis
d2ce285378 docs: make reporting-issues.rst official and delete reporting-bugs.rst
Remove the WIP and two FIXME notes in the text to make it official, as
it's now considered fully ready for consumption. To make sure this
step is okay for people the intent of this change and the latest version
of the text were posted to ksummit-discuss; nobody complained, thus
lets move ahead.

Add a footer to point out people can contact Thorsten directly in case
they find something to improve in the text.

Dear reporting-bugs.rst, I'm sorry to tell you, but that makes you fully
obsolete and we thus have to let you go now. Thank you very much for
your service, you in one form or another have been around for a long
time. I'm sure over the years you got read a lot and helped quite a few
people. But it's time to retire now. Rest in peace.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Harry Wei <harryxiyou@gmail.com>
CC: Alex Shi <alex.shi@linux.alibaba.com>
CC: Federico Vaga <federico.vaga@vaga.pv.it>
CC: Greg KH <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/49c674c2d304d87e6259063580fda05267e8c348.1617113469.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-31 13:33:17 -06:00
Mukesh Ojha
9d843e8faf pstore: Add mem_type property DT parsing support
There could be a scenario where we define some region
in normal memory and use them store to logs which is later
retrieved by bootloader during warm reset.

In this scenario, we wanted to treat this memory as normal
cacheable memory instead of default behaviour which
is an overhead. Making it cacheable could improve
performance.

This commit gives control to change mem_type from Device
tree, and also documents the value for normal memory.

Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/1616438537-13719-1-git-send-email-mojha@codeaurora.org
2021-03-31 10:06:23 -07:00
Qi Liu
b88f5e9792 docs: perf: Address some html build warnings
Fix following html build warnings:
Documentation/admin-guide/perf/hisi-pmu.rst:61: WARNING: Unexpected indentation.
Documentation/admin-guide/perf/hisi-pmu.rst:62: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/admin-guide/perf/hisi-pmu.rst:69: WARNING: Unexpected indentation.
Documentation/admin-guide/perf/hisi-pmu.rst:70: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/admin-guide/perf/hisi-pmu.rst:83: WARNING: Unexpected indentation.

Fixes: 9b86b1b41e0f ("docs: perf: Add new description on HiSilicon uncore PMU v2")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Qi Liu <liuqi115@huawei.com>
Link: https://lore.kernel.org/r/1617021121-31450-1-git-send-email-liuqi115@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-03-30 11:39:09 +01:00
Fenghua Yu
ebca17707e Documentation/admin-guide: Change doc for split_lock_detect parameter
Since #DB for bus lock detect changes the split_lock_detect parameter,
update the documentation for the changes.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210322135325.682257-4-fenghua.yu@intel.com
2021-03-28 22:52:16 +02:00
Andy Shevchenko
81dd500b1c gpio: mockup: Adjust documentation to the code
First of all one of the parameter missed 'mockup' in its name,
Second, the semantics of the integer pairs depends on the sign
of the base (the first value in the pair).

Update documentation to reflect the real code behaviour.

Fixes: 2fd1abe99e5f ("Documentation: gpio: add documentation for gpio-mockup")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2021-03-26 14:56:19 +01:00
Dmitry Vyukov
6c996e1994 net: change netdev_unregister_timeout_secs min value to 1
netdev_unregister_timeout_secs=0 can lead to printing the
"waiting for dev to become free" message every jiffy.
This is too frequent and unnecessary.
Set the min value to 1 second.

Also fix the merge issue introduced by
"net: make unregister netdev warning timeout configurable":
it changed "refcnt != 1" to "refcnt".

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Fixes: 5aa3afe107d9 ("net: make unregister netdev warning timeout configurable")
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-25 17:24:06 -07:00
Darrick J. Wong
3fef46fc43 xfs: rename the blockgc workqueue
Since we're about to start using the blockgc workqueue to dispose of
inactivated inodes, strip the "block" prefix from the name; now it's
merely the general garbage collection (gc) workqueue.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2021-03-25 16:47:50 -07:00
Thorsten Leemhuis
4b9d49d1ec docs: reporting-issues.rst: improved process esp. for stable regressions
Provide a shorter and easier process for users that deal with
regressions in stable and longterm kernels, as those should be reported
quickly.

To realize this in the least-confusing way and without having steps
multiple times in different places, split the 'search for existing
reports' into two. That has the additinal benefit that users will search
for them quickly when going through the step by step guide and thus will
save them trouble if the find reports.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
CC: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/d934c15e536bceeff5c40a126930ddf803548e08.1616181657.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25 12:16:46 -06:00
Thorsten Leemhuis
9bc4430db5 docs: reporting-issues.rst: duplicate sections for reviewing purposes
This duplicates two section to make the diff in the next patch a bit
easier to gasp for humans.

Straight copy, no content changes.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/ef85edc8466f035eb243dd6629429ad4fd0565d8.1616181657.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25 12:16:46 -06:00
Thorsten Leemhuis
4f08d7ab90 docs: reporting-issues.rst: reorder some steps
Reorder some steps where the order in which the readers perform them is
not crucial. This is a preparation for a later change that would make
the text much more complex otherwise.

Content just moved, not changed at all in the process.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/8dfc58efde25a05ccf9bf85929826c4b1b9e09c5.1616181657.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25 12:16:46 -06:00
Thorsten Leemhuis
2dfa9eb0ff docs: reporting-issues.rst: tone down 'test vanilla mainline' a little
Tell users that reporting bugs with vendor kernels which are only
slightly patched can be okay in some situations, but point out there's a
risk in doing so.

Adjust some related sections to make them compatible and a bit clearer.
At the same time make them less daunting: we want users to report bugs,
even if they can't test vanilla mainline kernel.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
CC: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/652ee20eb36228f5d7ca842299faa4cb472feedb.1616181657.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25 12:16:46 -06:00
Thorsten Leemhuis
613f969117 docs: reporting-issues.rst: fix small typos and style issues
Fix a typo and change "head over" to "scroll down", as suggested by Jon
when reviewing another patch that used the phrase the same way.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/fb845d2f1db6138337203bbfac419c04b5f28053.1616181657.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-25 12:16:46 -06:00
Shaokun Zhang
9b86b1b41e docs: perf: Add new description on HiSilicon uncore PMU v2
Some news functions are added on HiSilicon uncore PMUs. Document them
to provide guidance on how to use them.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Co-developed-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Link: https://lore.kernel.org/r/1615186237-22263-10-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-03-25 13:03:46 +00:00
Paul E. McKenney
ab6ad3dbdd Merge branches 'bitmaprange.2021.03.08a', 'fixes.2021.03.15a', 'kvfree_rcu.2021.03.08a', 'mmdumpobj.2021.03.08a', 'nocb.2021.03.15a', 'poll.2021.03.24a', 'rt.2021.03.08a', 'tasks.2021.03.08a', 'torture.2021.03.08a' and 'torturescript.2021.03.22a' into HEAD
bitmaprange.2021.03.08a:  Allow 3-N for bitmap ranges.
fixes.2021.03.15a:  Miscellaneous fixes.
kvfree_rcu.2021.03.08a:  kvfree_rcu() updates.
mmdumpobj.2021.03.08a:  mem_dump_obj() updates.
nocb.2021.03.15a:  RCU NOCB CPU updates, including limited deoffloading.
poll.2021.03.24a:  Polling grace-period interfaces for RCU.
rt.2021.03.08a:  Realtime-related RCU changes.
tasks.2021.03.08a:  Tasks-RCU updates.
torture.2021.03.08a:  Torture-test updates.
torturescript.2021.03.22a:  Torture-test scripting updates.
2021-03-24 17:20:18 -07:00
Dmitry Vyukov
5aa3afe107 net: make unregister netdev warning timeout configurable
netdev_wait_allrefs() issues a warning if refcount does not drop to 0
after 10 seconds. While 10 second wait generally should not happen
under normal workload in normal environment, it seems to fire falsely
very often during fuzzing and/or in qemu emulation (~10x slower).
At least it's not possible to understand if it's really a false
positive or not. Automated testing generally bumps all timeouts
to very high values to avoid flake failures.
Add net.core.netdev_unregister_timeout_secs sysctl to make
the timeout configurable for automated testing systems.
Lowering the timeout may also be useful for e.g. manual bisection.
The default value matches the current behavior.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=211877
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-23 17:22:50 -07:00
Nitin Joshi
3feb52a2b8 platform/x86: thinkpad_acpi: sysfs interface to get wwan antenna type
On some newer Thinkpads we need to set SAR value based on antenna type.
This patch provides a sysfs interface that userspace can use to get
antenna type and set corresponding SAR value, as is required for FCC
certification.

Reviewed-by: Mark Pearson <markpearson@lenovo.com>
Signed-off-by: Nitin Joshi <njoshi1@lenovo.com>
Link: https://lore.kernel.org/r/20210317024636.356175-1-njoshi1@lenovo.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2021-03-21 18:04:19 +01:00
Robin Murphy
3542dcb15c iommu/dma: Resurrect the "forcedac" option
In converting intel-iommu over to the common IOMMU DMA ops, it quietly
lost the functionality of its "forcedac" option. Since this is a handy
thing both for testing and for performance optimisation on certain
platforms, reimplement it under the common IOMMU parameter namespace.

For the sake of fixing the inadvertent breakage of the Intel-specific
parameter, remove the dmar_forcedac remnants and hook it up as an alias
while documenting the transition to the new common parameter.

Fixes: c588072bba6b ("iommu/vt-d: Convert intel iommu driver to the iommu ops")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/7eece8e0ea7bfbe2cd0e30789e0d46df573af9b0.1614961776.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-03-18 10:55:23 +01:00
Gao Xiang
a8f2a68e42 Documentation: sysrq: update description about sysrq crash
After commit 8341f2f222d7 ("sysrq: Use panic() to force a crash"),
a crash was not generated by dereferencing a NULL pointer anymore.

Let's update documentation as well to make it less misleading.

Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Zefan Li <lizefan.x@bytedance.com>
Link: https://lore.kernel.org/r/20210309191550.3955601-1-hsiangkao@redhat.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-15 14:23:21 -06:00
Jiele zhao
0860b72d53 security/loadpin: Update the changing interface in the source code.
Loadpin cmdline interface "enabled" has been renamed to "enforce"
for a long time, but the User Description Document was not updated.
(Meaning unchanged)

And kernel_read_file* were moved from linux/fs.h to its own
linux/kernel_read_file.h include file. So update that change here.

Signed-off-by: Jiele zhao <unclexiaole@gmail.com>
Link: https://lore.kernel.org/r/20210308020358.102836-1-unclexiaole@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-15 13:32:32 -06:00
Bhaskar Chowdhury
fdebeae0d7 docs: admin-guide: cgroup-v1: Fix typos in the file memory.rst
s/overcommited/overcommitted/
s/Overcommiting/Overcommitting/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210313061029.28024-1-unixbhaskar@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-15 13:03:25 -06:00
Jiri Slaby
67b1544a55 tty: isicom, remove this orphan
The Isicom driver was orphaned by commit d86b3001a1a6 (MAINTAINERS:
orphan isicom) 10 years ago. Noone stepped up to take care of them and
to fix all the issues the driver has.

So it's time to drop the driver with all its traces.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:34:06 +01:00
Jiri Slaby
f76edd8f7c tty: cyclades, remove this orphan
The Cyclades driver was orphaned by commit d459883e6c54 (MAINTAINERS:
remove two dead e-mail) 13 years ago. Noone stepped up to take care of
them and to fix all the issues the driver has.

On the top of that, there is no way to obtain the firmware for Z cards
from the vendor as cyclades.com ceased to exist.

So it's time to drop the driver with all its traces.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:34:06 +01:00
Kefeng Wang
f6e5aedf47
riscv: Add support for memtest
The riscv [rv32_]defconfig enabled CONFIG_MEMTEST,
but memtest feature is not supported in RISCV.

Add early_memtest() to support for memtest.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-09 18:09:46 -08:00
Barry Song
00b072c011 Documentation/admin-guide: kernel-parameters: correct the architectures for numa_balancing
X86 isn't the only architecture supporting NUMA_BALANCING. ARM64, PPC,
S390 and RISCV also support it:

arch$ git grep NUMA_BALANCING
arm64/Kconfig:  select ARCH_SUPPORTS_NUMA_BALANCING
arm64/configs/defconfig:CONFIG_NUMA_BALANCING=y
arm64/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING
powerpc/configs/powernv_defconfig:CONFIG_NUMA_BALANCING=y
powerpc/configs/ppc64_defconfig:CONFIG_NUMA_BALANCING=y
powerpc/configs/pseries_defconfig:CONFIG_NUMA_BALANCING=y
powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING
powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING
powerpc/include/asm/book3s/64/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */
powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING
powerpc/include/asm/book3s/64/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */
powerpc/include/asm/nohash/pgtable.h:#ifdef CONFIG_NUMA_BALANCING
powerpc/include/asm/nohash/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */
powerpc/platforms/Kconfig.cputype:      select ARCH_SUPPORTS_NUMA_BALANCING
riscv/Kconfig:  select ARCH_SUPPORTS_NUMA_BALANCING
riscv/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING
s390/Kconfig:   select ARCH_SUPPORTS_NUMA_BALANCING
s390/configs/debug_defconfig:CONFIG_NUMA_BALANCING=y
s390/configs/defconfig:CONFIG_NUMA_BALANCING=y
s390/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING
x86/Kconfig:    select ARCH_SUPPORTS_NUMA_BALANCING     if X86_64
x86/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING
x86/include/asm/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */

On the other hand, setup_numabalancing() is implemented in mm/mempolicy.c
which doesn't depend on architectures.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210302084159.33688-1-song.bao.hua@hisilicon.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-08 17:19:05 -07:00
Martin Kepplinger
e85d92b3bc Documentation: dynamic-debug-howto: fix example
dynamic debug is "expecting pairs of match-spec <value>" so the example
for all files of which the paths include "usb" there is "file" missing.

Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Link: https://lore.kernel.org/r/20210303091646.773111-1-martin.kepplinger@puri.sm
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-08 17:09:26 -07:00
Uladzislau Rezki (Sony)
686fe1bf6b rcuscale: Add kfree_rcu() single-argument scale test
The single-argument variant of kfree_rcu() is currently not
tested by any member of the rcutoture test suite.  This
commit therefore adds rcuscale code to test it.  This
testing is controlled by two new boolean module parameters,
kfree_rcu_test_single and kfree_rcu_test_double.  If one
is set and the other not, only the corresponding variant
is tested, otherwise both are tested, with the variant to
be tested determined randomly on each invocation.

Both of these module parameters are initialized to false,
so setting either to true will test only that variant.

Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-08 14:18:07 -08:00
Paul Gortmaker
3e70df91f9 rcu: deprecate "all" option to rcu_nocbs=
With the core bitmap support now accepting "N" as a placeholder for
the end of the bitmap, "all" can be represented as "0-N" and has the
advantage of not being specific to RCU (or any other subsystem).

So deprecate the use of "all" by removing documentation references
to it.  The support itself needs to remain for now, since we don't
know how many people out there are using it currently, but since it
is in an __init area anyway, it isn't worth losing sleep over.

Cc: Yury Norov <yury.norov@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-08 14:16:58 -08:00
Paul Gortmaker
2c4885d24e lib: bitmap: support "N" as an alias for size of bitmap
While this is done for all bitmaps, the original use case in mind was
for CPU masks and cpulist_parse() as described below.

It seems that a common configuration is to use the 1st couple cores for
housekeeping tasks.  This tends to leave the remaining ones to form a
pool of similarly configured cores to take on the real workload of
interest to the user.

So on machine A - with 32 cores, it could be 0-3 for "system" and then
4-31 being used in boot args like nohz_full=, or rcu_nocbs= as part of
setting up the worker pool of CPUs.

But then newer machine B is added, and it has 48 cores, and so while
the 0-3 part remains unchanged, the pool setup cpu list becomes 4-47.

Multiple deployment becomes easier when we can just simply replace 31
and 47 with "N" and let the system substitute in the actual number at
boot; a number that it knows better than we do.

Cc: Yury Norov <yury.norov@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Yury Norov <yury.norov@gmail.com> # move it from CPU code
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-08 14:16:58 -08:00
Rafael J. Wysocki
866d6cdf35 ACPI: PCI: Drop ACPI_PCI_COMPONENT that is not used any more
After dropping all of the code using ACPI_PCI_COMPONENT drop the
definition of it too and update the documentation to remove all
ACPI_PCI_COMPONENT references from it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
2021-03-08 16:51:09 +01:00
Thorsten Leemhuis
315c4e45f1 docs: reporting-issues.rst: explain how to decode stack traces
Replace placeholder text about decoding stack traces with a section that
properly describes what a typical user should do these days. To make
it works for them, add a paragraph in an earlier section to ensure
people build their kernels with everything that's needed to decode stack
traces later.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: Qais Yousef <qais.yousef@arm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20210215172857.382285-1-linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-06 17:36:52 -07:00
Yang Shi
1eff491fc4 doc: memcontrol: add description for oom_kill
When debugging an oom issue, I found the oom_kill counter of memcg is
confusing.  At the first glance without checking document, I thought it
just counts for memcg oom, but it turns out it counts both global and
memcg oom.

The cgroup v2 documents it, but the description is missed for cgroup v1.

Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Chris Down <chris@chrisdown.name>
Link: https://lore.kernel.org/r/20210226021254.3980-1-shy828301@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-06 17:36:50 -07:00
Juergen Gross
a5aabace5f locking/csd_lock: Add more data to CSD lock debugging
In order to help identifying problems with IPI handling and remote
function execution add some more data to IPI debugging code.

There have been multiple reports of CPUs looping long times (many
seconds) in smp_call_function_many() waiting for another CPU executing
a function like tlb flushing. Most of these reports have been for
cases where the kernel was running as a guest on top of KVM or Xen
(there are rumours of that happening under VMWare, too, and even on
bare metal).

Finding the root cause hasn't been successful yet, even after more than
2 years of chasing this bug by different developers.

Commit:

  35feb60474bf4f7 ("kernel/smp: Provide CSD lock timeout diagnostics")

tried to address this by adding some debug code and by issuing another
IPI when a hang was detected. This helped mitigating the problem
(the repeated IPI unlocks the hang), but the root cause is still unknown.

Current available data suggests that either an IPI wasn't sent when it
should have been, or that the IPI didn't result in the target CPU
executing the queued function (due to the IPI not reaching the CPU,
the IPI handler not being called, or the handler not seeing the queued
request).

Try to add more diagnostic data by introducing a global atomic counter
which is being incremented when doing critical operations (before and
after queueing a new request, when sending an IPI, and when dequeueing
a request). The counter value is stored in percpu variables which can
be printed out when a hang is detected.

The data of the last event (consisting of sequence counter, source
CPU, target CPU, and event type) is stored in a global variable. When
a new event is to be traced, the data of the last event is stored in
the event related percpu location and the global data is updated with
the new event's data. This allows to track two events in one data
location: one by the value of the event data (the event before the
current one), and one by the location itself (the current event).

A typical printout with a detected hang will look like this:

csd: Detected non-responsive CSD lock (#1) on CPU#1, waiting 5000000003 ns for CPU#06 scf_handler_1+0x0/0x50(0xffffa2a881bb1410).
	csd: CSD lock (#1) handling prior scf_handler_1+0x0/0x50(0xffffa2a8813823c0) request.
        csd: cnt(00008cc): ffff->0000 dequeue (src cpu 0 == empty)
        csd: cnt(00008cd): ffff->0006 idle
        csd: cnt(0003668): 0001->0006 queue
        csd: cnt(0003669): 0001->0006 ipi
        csd: cnt(0003e0f): 0007->000a queue
        csd: cnt(0003e10): 0001->ffff ping
        csd: cnt(0003e71): 0003->0000 ping
        csd: cnt(0003e72): ffff->0006 gotipi
        csd: cnt(0003e73): ffff->0006 handle
        csd: cnt(0003e74): ffff->0006 dequeue (src cpu 0 == empty)
        csd: cnt(0003e7f): 0004->0006 ping
        csd: cnt(0003e80): 0001->ffff pinged
        csd: cnt(0003eb2): 0005->0001 noipi
        csd: cnt(0003eb3): 0001->0006 queue
        csd: cnt(0003eb4): 0001->0006 noipi
        csd: cnt now: 0003f00

The idea is to print only relevant entries. Those are all events which
are associated with the hang (so sender side events for the source CPU
of the hanging request, and receiver side events for the target CPU),
and the related events just before those (for adding data needed to
identify a possible race). Printing all available data would be
possible, but this would add large amounts of data printed on larger
configurations.

Signed-off-by: Juergen Gross <jgross@suse.com>
[ Minor readability edits. Breaks col80 but is far more readable. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20210301101336.7797-4-jgross@suse.com
2021-03-06 12:49:48 +01:00
Juergen Gross
8d0968cc6b locking/csd_lock: Add boot parameter for controlling CSD lock debugging
Currently CSD lock debugging can be switched on and off via a kernel
config option only. Unfortunately there is at least one problem with
CSD lock handling pending for about 2 years now, which has been seen
in different environments (mostly when running virtualized under KVM
or Xen, at least once on bare metal). Multiple attempts to catch this
issue have finally led to introduction of CSD lock debug code, but
this code is not in use in most distros as it has some impact on
performance.

In order to be able to ship kernels with CONFIG_CSD_LOCK_WAIT_DEBUG
enabled even for production use, add a boot parameter for switching
the debug functionality on. This will reduce any performance impact
of the debug coding to a bare minimum when not being used.

Signed-off-by: Juergen Gross <jgross@suse.com>
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210301101336.7797-2-jgross@suse.com
2021-03-06 12:49:48 +01:00
Linus Torvalds
03dc748bf1 More new code for 5.12:
- Restore a disused sysctl control knob that was inadvertently dropped
   during the merge window to avoid fstests regressions.
 - Don't speculatively release freed blocks from the busy list until
   we're actually allocating them, which fixes a rare log recovery
   regression.
 - Don't nest transactions when scanning for free space.
 - Add an idiot^Wmaintainer light to detect nested transactions. ;)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAmA3zW8ACgkQ+H93GTRK
 tOtT4xAAmZ5BdQ6V3yUeT/N++L6Ax62T2VzEryZvVK/ZFyVBRYKi9LOL1exq1cja
 HXINPuYWAD8TbGVU9/lZR1yUX/y1VvJR0EPly8EN6WpGFeErSxLs++YzP1Q8iv5i
 ZtniscpGE6JvCcDeRH5kBfklGpyzTf3t6Xe8x+6+/aawf34ChNlM/gQcAyKvYYU5
 Jb9j7BqbRAnhvPEfa554yxIIoZhmTDYY7Wx7VMKCMcOP1lfriC+I1iuiZIMONIQJ
 mMgz9XnHVo256+YvkvwRKp294r+MEkuJL5EBXrs01r3PwVdaigo13qTk8l1ZC3zS
 VYkC/sRoiyMwnJvKEUNtnM3/8Zu/DvPp9iqXiWc60UBGqpBkm8Jgv+W6H7u1FinP
 0M0Wt2wHC7e51uW5G/8QwUXZv+n8IZHyZkkYbjyXRkhfyFlexYwTVchZz9q/RB/A
 HEZ9jcIke8Rwkav4f0kJ00Y/7FQSPn6ItapXf92rl00z3Z5S2sqBaT5kIotsW0Ke
 634yPknkLuBDQg4j8l3A88ik2SNFRQQfBXsjt27He/s2wV0Dj8RjDnLWfoV7P5to
 Sc2lx3HhL4OCojAXXAFP3MDKz0nqcuUTPoPCeS6QKQGcjTzVvoI7ZutXODcxi67k
 Q7AK+gIqHRWA8F+4wciYDwAHMES1rRAa7/iuYmtCtT1sBdXp9NU=
 =g9K3
 -----END PGP SIGNATURE-----

Merge tag 'xfs-5.12-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull more xfs updates from Darrick Wong:
 "The most notable fix here prevents premature reuse of freed metadata
  blocks, and adding the ability to detect accidental nested
  transactions, which are not allowed here.

   - Restore a disused sysctl control knob that was inadvertently
     dropped during the merge window to avoid fstests regressions.

   - Don't speculatively release freed blocks from the busy list until
     we're actually allocating them, which fixes a rare log recovery
     regression.

   - Don't nest transactions when scanning for free space.

   - Add an idiot^Wmaintainer light to detect nested transactions. ;)"

* tag 'xfs-5.12-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: use current->journal_info for detecting transaction recursion
  xfs: don't nest transactions when scanning for eofblocks
  xfs: don't reuse busy extents on extent trim
  xfs: restore speculative_cow_prealloc_lifetime sysctl
2021-02-28 11:45:25 -08:00
Linus Torvalds
3fb6d0e00e A handful of late-arriving documentation fixes, nothing all that notable.
-----BEGIN PGP SIGNATURE-----
 
 iQFDBAABCAAtFiEEIw+MvkEiF49krdp9F0NaE2wMflgFAmA5Qu8PHGNvcmJldEBs
 d24ubmV0AAoJEBdDWhNsDH5Yiz0H/jTF+JcYstvGINx7jLZH4j9Pa4b/IZ3RO5uR
 OpjkzhTNangk2pSS4nuoQGjDRz1miBRaY1yE923Wxk1T1Nk+DA6aYJbVTqpn962S
 Z5IyQWzMIHFTAhSle0GeuTBk9Qx46ONhBJH1qsHCraAUtsQrxSUoF95ZftKD54gz
 Eg+eFQscHen9on2ZlqypauZebVbAa3zq1JCyohK5URiXLXpNq7ASCcOZ6v1OJb76
 thgxOQgb1/TQ+ZNEeRs8Bv5g6kcTlWhapIrnsYPrmCEYaj2ghvGbbSlWyAmJRPqT
 PH+ucFCyjZqGcPmM5zerhVI+scQOLAJigAQa/B6HhRfmCyI1kkE=
 =ZKHc
 -----END PGP SIGNATURE-----

Merge tag 'docs-5.12-2' of git://git.lwn.net/linux

Pull documentation fixes from Jonathan Corbet:
 "A handful of late-arriving documentation fixes, nothing all that
  notable"

* tag 'docs-5.12-2' of git://git.lwn.net/linux:
  docs: proc.rst: fix indentation warning
  Documentation: cgroup-v2: fix path to example BPF program
  docs: powerpc: Fix tables in syscall64-abi.rst
  Documentation: features: refresh feature list
  Documentation: features: remove c6x references
  docs: ABI: testing: ima_policy: Fixed missing bracket
  Fix unaesthetic indentation
  scripts: kernel-doc: fix array element capture in pointer-to-func parsing
  doc: use KCFLAGS instead of EXTRA_CFLAGS to pass flags from command line
  Documentation: proc.rst: add more about the 6 fields in loadavg
2021-02-26 14:21:18 -08:00
Linus Torvalds
c19798af2e cifs/smb3 fixes including improvements to mode bit conversion when using cifsacl mount option, new mount options for controlling attribute caching, improvements to crediting and reconnect, improved debugging
-----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEE6fsu8pdIjtWE/DpLiiy9cAdyT1EFAmA4bocACgkQiiy9cAdy
 T1HuMwv/bmZ53ilDwhCph/UKoLJm/bRyvCp+GBECtLLS/C/4qz5IBLpPPr2yhOyH
 gmkeCZZWhj0nzGAYxhVDAdBz9IPEA7bae503IaOuk5uXaCXC8htsq/Cd7qpJmHlf
 5vCdBTmHBiUt02dUcZ9A3bm855xJLEINHH9YdJM157ysqLgttIibLQB0F/gJ49DR
 QIIdq7sZNJXcTgRsUzJZNnrWLDi2oVIoUlq5M6d8ypmZC0ArPNfrSafjW6h5rqpj
 UYBwtUDNwQiS0lgwR4mji4PCen0GGwMFtyVDOpdJLJq3fO995yse2BRk0BFHVH1i
 xfAskQjkxAHEcfzQC1cM4ouT/WYu8nHaLK1vp/1lVr93mo8KqSX+SW/bLsXfpQkm
 w//xMy94HdM2pgyM6J1pYnKPb7s/DG19RYPktQ5oYn0fR5qYlqALAmd02JRjO3xV
 cbjbmWXXzFFsFJc5MJmM6wVLJzRb4a50SN1W37aHNXWi8ktpsaNzz33LGw1pF2OT
 K6P2DqJe
 =RQo/
 -----END PGP SIGNATURE-----

Merge tag '5.12-smb3-part1' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs updates from Steve French:

 - improvements to mode bit conversion, chmod and chown when using
   cifsacl mount option

 - two new mount options for controlling attribute caching

 - improvements to crediting and reconnect, improved debugging

 - reconnect fix

 - add SMB3.1.1 dialect to default dialects for vers=3

* tag '5.12-smb3-part1' of git://git.samba.org/sfrench/cifs-2.6: (27 commits)
  cifs: update internal version number
  cifs: use discard iterator to discard unneeded network data more efficiently
  cifs: introduce helper for finding referral server to improve DFS target resolution
  cifs: check all path components in resolved dfs target
  cifs: fix DFS failover
  cifs: fix nodfs mount option
  cifs: fix handling of escaped ',' in the password mount argument
  cifs: Add new parameter "acregmax" for distinct file and directory metadata timeout
  cifs: convert revalidate of directories to using directory metadata cache timeout
  cifs: Add new mount parameter "acdirmax" to allow caching directory metadata
  cifs: If a corrupted DACL is returned by the server, bail out.
  cifs: minor simplification to smb2_is_network_name_deleted
  TCON Reconnect during STATUS_NETWORK_NAME_DELETED
  cifs: cleanup a few le16 vs. le32 uses in cifsacl.c
  cifs: Change SIDs in ACEs while transferring file ownership.
  cifs: Retain old ACEs when converting between mode bits and ACL.
  cifs: Fix cifsacl ACE mask for group and others.
  cifs: clarify hostname vs ip address in /proc/fs/cifs/DebugData
  cifs: change confusing field serverName (to ip_addr)
  cifs: Fix inconsistent IS_ERR and PTR_ERR
  ...
2021-02-26 14:09:41 -08:00
Vijayanand Jitta
e1fdc40334 lib: stackdepot: add support to disable stack depot
Add a kernel parameter stack_depot_disable to disable stack depot.  So
that stack hash table doesn't consume any memory when stack depot is
disabled.

The use case is CONFIG_PAGE_OWNER without page_owner=on.  Without this
patch, stackdepot will consume the memory for the hashtable.  By default,
it's 8M which is never trivial.

With this option, in CONFIG_PAGE_OWNER configured system, page_owner=off,
stack_depot_disable in kernel command line, we could save the wasted
memory for the hashtable.

[akpm@linux-foundation.org: fix CONFIG_STACKDEPOT=n build]

Link: https://lkml.kernel.org/r/1611749198-24316-2-git-send-email-vjitta@codeaurora.org
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yogesh Lal <ylal@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:41:04 -08:00
Miguel Ojeda
c131bd0b54 treewide: Miguel has moved
Update contact info.

Link: https://lkml.kernel.org/r/20210206162524.GA11520@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:41:03 -08:00
David Hildenbrand
a89107c047 Documentation: sysfs/memory: clarify some memory block device properties
In commit 53cdc1cb29e8 ("drivers/base/memory.c: indicate all memory blocks
as removable") we changed the output of the "removable" property of memory
devices to return "1" if and only if the kernel supports memory offlining.

Let's update documentation, stating that the interface is legacy.  Also
update documentation of the "state" property and "valid_zones" properties.

Link: https://lkml.kernel.org/r/20210201181347.13262-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:41:00 -08:00
David Hildenbrand
e9a2e48e87 drivers/base/memory: don't store phys_device in memory blocks
No need to store the value for each and every memory block, as we can
easily query the value at runtime.  Reshuffle the members to optimize the
memory layout.  Also, let's clarify what the interface once was used for
and why it's legacy nowadays.

"phys_device" was used on s390x in older versions of lsmem[2]/chmem[3],
back when they were still part of s390x-tools.  They were later replaced
by the variants in linux-utils.  For example, RHEL6 and RHEL7 contain
lsmem/chmem from s390-utils.  RHEL8 switched to versions from util-linux
on s390x [4].

"phys_device" was added with sysfs support for memory hotplug in commit
3947be1969a9 ("[PATCH] memory hotplug: sysfs and add/remove functions") in
2005.  It always returned 0.

s390x started returning something != 0 on some setups (if sclp.rzm is set
by HW) in 2010 via commit 57b552ba0b2f ("memory hotplug/s390: set
phys_device").

For s390x, it allowed for identifying which memory block devices belong to
the same storage increment (RZM).  Only if all memory block devices
comprising a single storage increment were offline, the memory could
actually be removed in the hypervisor.

Since commit e5d709bb5fb7 ("s390/memory hotplug: provide
memory_block_size_bytes() function") in 2013 a memory block device spans
at least one storage increment - which is why the interface isn't really
helpful/used anymore (except by old lsmem/chmem tools).

There were once RFC patches to make use of "phys_device" in ACPI context;
however, the underlying problem could be solved using different interfaces
[1].

[1] https://patchwork.kernel.org/patch/2163871/
[2] https://github.com/ibm-s390-tools/s390-tools/blob/v2.1.0/zconf/lsmem
[3] https://github.com/ibm-s390-tools/s390-tools/blob/v2.1.0/zconf/chmem
[4] https://bugzilla.redhat.com/show_bug.cgi?id=1504134

Link: https://lkml.kernel.org/r/20210201181347.13262-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Tom Rix <trix@redhat.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:41:00 -08:00
Antonio Terceiro
43c4f657c8 Documentation: cgroup-v2: fix path to example BPF program
This file has been moved into the "progs" subdirectory, together with all
test BPF programs.

Fixes: bd4aed0ee73c ("selftests: bpf: centre kernel bpf objects under new subdir "progs"")
Signed-off-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jiong Wang <jiong.wang@netronome.com>
Link: https://lore.kernel.org/r/20210224131631.349287-1-antonio.terceiro@linaro.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-02-25 13:07:31 -07:00
Linus Torvalds
4c48faba5b Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "A few small subsystems and some of MM.

  172 patches.

  Subsystems affected by this patch series: hexagon, scripts, ntfs,
  ocfs2, vfs, and mm (slab-generic, slab, slub, debug, pagecache, swap,
  memcg, pagemap, mprotect, mremap, page-reporting, vmalloc, kasan,
  pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
  mempolicy, oom-kill, hugetlbfs, and migration)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (172 commits)
  mm/migrate: remove unneeded semicolons
  hugetlbfs: remove unneeded return value of hugetlb_vmtruncate()
  hugetlbfs: fix some comment typos
  hugetlbfs: correct some obsolete comments about inode i_mutex
  hugetlbfs: make hugepage size conversion more readable
  hugetlbfs: remove meaningless variable avoid_reserve
  hugetlbfs: correct obsolete function name in hugetlbfs_read_iter()
  hugetlbfs: use helper macro default_hstate in init_hugetlbfs_fs
  hugetlbfs: remove useless BUG_ON(!inode) in hugetlbfs_setattr()
  hugetlbfs: remove special hugetlbfs_set_page_dirty()
  mm/hugetlb: change hugetlb_reserve_pages() to type bool
  mm, oom: fix a comment in dump_task()
  mm/mempolicy: use helper range_in_vma() in queue_pages_test_walk()
  numa balancing: migrate on fault among multiple bound nodes
  mm, compaction: make fast_isolate_freepages() stay within zone
  mm/compaction: fix misbehaviors of fast_find_migrateblock()
  mm/compaction: correct deferral logic for proactive compaction
  mm/compaction: remove duplicated VM_BUG_ON_PAGE !PageLocked
  mm/compaction: remove rcu_read_lock during page compaction
  z3fold: simplify the zhdr initialization code in init_z3fold_page()
  ...
2021-02-24 16:20:38 -08:00
Dave Hansen
519983645a mm/vmscan: restore zone_reclaim_mode ABI
I went to go add a new RECLAIM_* mode for the zone_reclaim_mode sysctl.
Like a good kernel developer, I also went to go update the
documentation.  I noticed that the bits in the documentation didn't
match the bits in the #defines.

The VM never explicitly checks the RECLAIM_ZONE bit.  The bit is,
however implicitly checked when checking 'node_reclaim_mode==0'.  The
RECLAIM_ZONE #define was removed in a cleanup.  That, by itself is fine.

But, when the bit was removed (bit 0) the _other_ bit locations also got
changed.  That's not OK because the bit values are documented to mean
one specific thing.  Users surely do not expect the meaning to change
from kernel to kernel.

The end result is that if someone had a script that did:

	sysctl vm.zone_reclaim_mode=1

it would have gone from enabling node reclaim for clean unmapped pages
to writing out pages during node reclaim after the commit in question.
That's not great.

Put the bits back the way they were and add a comment so something like
this is a bit harder to do again.  Update the documentation to make it
clear that the first bit is ignored.

Link: https://lkml.kernel.org/r/20210219172555.FF0CDF23@viggo.jf.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Fixes: 648b5cf368e0 ("mm/vmscan: remove unused RECLAIM_OFF/RECLAIM_ZONE")
Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Daniel Wagner <dwagner@suse.de>
Cc: "Tobin C. Harding" <tobin@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:34 -08:00
Shakeel Butt
b603894248 mm: memcg: add swapcache stat for memcg v2
This patch adds swapcache stat for the cgroup v2.  The swapcache
represents the memory that is accounted against both the memory and the
swap limit of the cgroup.  The main motivation behind exposing the
swapcache stat is for enabling users to gracefully migrate from cgroup
v1's memsw counter to cgroup v2's memory and swap counters.

Cgroup v1's memsw limit allows users to limit the memory+swap usage of a
workload but without control on the exact proportion of memory and swap.
Cgroup v2 provides separate limits for memory and swap which enables more
control on the exact usage of memory and swap individually for the
workload.

With some little subtleties, the v1's memsw limit can be switched with the
sum of the v2's memory and swap limits.  However the alternative for memsw
usage is not yet available in cgroup v2.  Exposing per-cgroup swapcache
stat enables that alternative.  Adding the memory usage and swap usage and
subtracting the swapcache will approximate the memsw usage.  This will
help in the transparent migration of the workloads depending on memsw
usage and limit to v2' memory and swap counters.

The reasons these applications are still interested in this approximate
memsw usage are: (1) these applications are not really interested in two
separate memory and swap usage metrics.  A single usage metric is more
simple to use and reason about for them.

(2) The memsw usage metric hides the underlying system's swap setup from
the applications.  Applications with multiple instances running in a
datacenter with heterogeneous systems (some have swap and some don't) will
keep seeing a consistent view of their usage.

[akpm@linux-foundation.org: fix CONFIG_SWAP=n build]

Link: https://lkml.kernel.org/r/20210108155813.2914586-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:29 -08:00
Vlastimil Babka
fe2cce15d6 mm, slub: remove slub_memcg_sysfs boot param and CONFIG_SLUB_MEMCG_SYSFS_ON
The boot param and config determine the value of memcg_sysfs_enabled,
which is unused since commit 10befea91b61 ("mm: memcg/slab: use a single
set of kmem_caches for all allocations") as there are no per-memcg kmem
caches anymore.

Link: https://lkml.kernel.org/r/20210127124745.7928-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24 13:38:27 -08:00
Linus Torvalds
c4fbde84fe Simple Firmware Interface (SFI) support removal for v5.12-rc1
Drop support for depercated platforms using SFI, drop the entire
 support for SFI that has been long deprecated too and make some
 janitorial changes on top of that (Andy Shevchenko).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAmA2ZukSHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRxKcAP/RAkbRVFndhQIZYTCu74O64v86FjTBcS
 3vvcKevVkBJiPJL1l10Yo3UMEYAbJIRZY00jkUjX7pq4eurELu6LwdMtJlHwh0p5
 ZP5QeSdq1xN+9UGwBGXlnka2ypmD8fjbQyxHKErYgvmOl4ltFm40PyUC9GCVFLnW
 /1o83t/dcmTtaOGPYWTW3HuCsbYqANG/x8PYAFeAk5dBxoSaNV69gAEuCYr1JC5N
 Nie4x2m2I5v9egJFhy6rmRrpHPBvocCho+FipJFagSKWHPCI2rBSKESVOj23zWt2
 eIWhK5T/ZR3OqQb9tZN6uAPJmBAerc3l7ZHZ1oFBP68MjUJJJhduQ+hNxljOyLLw
 CVx0UhuancIWZdyJon5f7E9S9STZLIZ/3usx3K+7AZK+PSmH8d/UEIeXfkC0FcAr
 eO3gwalB9KuhhXbVvihW79RkfkV5pTaMvVS7l1BffN4WE1dB9PKtJ8/MKFbGaTUF
 4Rev6BdAEDqJrw6OIARvNcI6TAEhbKe5yIghzhQWn+fZ7oEm6f6fvFObBzD0KvQP
 4RwYJhXU0gtK5yo/Ib1sUqjVQn8Jgqb7Xq46WZsP07Yc6O2Ws/86qCpX1GSCv5FU
 1CZEJLGLGTbjDYOyMaUDfO/tI5kXG11e0Ss7Q+snWH4Iyhg0aNEYChKjOAFIxIxg
 JJYOH8O5p2IP
 =jlPz
 -----END PGP SIGNATURE-----

Merge tag 'sfi-removal-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull Simple Firmware Interface (SFI) support removal from Rafael Wysocki:
 "Drop support for depercated platforms using SFI, drop the entire
  support for SFI that has been long deprecated too and make some
  janitorial changes on top of that (Andy Shevchenko)"

* tag 'sfi-removal-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  x86/platform/intel-mid: Update Copyright year and drop file names
  x86/platform/intel-mid: Remove unused header inclusion in intel-mid.h
  x86/platform/intel-mid: Drop unused __intel_mid_cpu_chip and Co.
  x86/platform/intel-mid: Get rid of intel_scu_ipc_legacy.h
  x86/PCI: Describe @reg for type1_access_ok()
  x86/PCI: Get rid of custom x86 model comparison
  sfi: Remove framework for deprecated firmware
  cpufreq: sfi-cpufreq: Remove driver for deprecated firmware
  media: atomisp: Remove unused header
  mfd: intel_msic: Remove driver for deprecated platform
  x86/apb_timer: Remove driver for deprecated platform
  x86/platform/intel-mid: Remove unused leftovers (vRTC)
  x86/platform/intel-mid: Remove unused leftovers (msic)
  x86/platform/intel-mid: Remove unused leftovers (msic_thermal)
  x86/platform/intel-mid: Remove unused leftovers (msic_power_btn)
  x86/platform/intel-mid: Remove unused leftovers (msic_gpio)
  x86/platform/intel-mid: Remove unused leftovers (msic_battery)
  x86/platform/intel-mid: Remove unused leftovers (msic_ocd)
  x86/platform/intel-mid: Remove unused leftovers (msic_audio)
  platform/x86: intel_scu_wdt: Drop mistakenly added const
2021-02-24 10:35:29 -08:00