Commit Graph

2659 Commits

Author SHA1 Message Date
Jonathan Corbet
e4624435f3 docs: arm64: Move arm64 documentation under Documentation/arch/
Architecture-specific documentation is being moved into Documentation/arch/
as a way of cleaning up the top-level documentation directory and making
the docs hierarchy more closely match the source hierarchy.  Move
Documentation/arm64 into arch/ (along with the Chinese equvalent
translations) and fix up documentation references.

Cc: Will Deacon <will@kernel.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Hu Haowen <src.res@email.cn>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Yantengsi <siyanteng@loongson.cn>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-06-21 08:51:51 -06:00
SeongJae Park
ff71f26f97 Docs/admin-guide/mm/damon/usage: update the ways for getting monitoring results
The recommended ways for getting DAMON monitoring results are using
tried_regions sysfs directory for partial snapshot of the results, and
DAMON tracepoint for full record of the results.  However, the
tried_regions sysfs directory usage has not sufficiently updated on some
sections of the DAMON usage document.  Update those.

Link: https://lkml.kernel.org/r/20230616191742.87531-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:37 -07:00
SeongJae Park
67c34f6c6a Docs/admin-guide/mm/damon/usage: clarify quotas and watermarks sysfs interface
Explanation of DAMOS quotas and watermarks are not clearly explaining the
meaning and expectation of each file.  Add more clarification for those.

Link: https://lkml.kernel.org/r/20230616191742.87531-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:37 -07:00
SeongJae Park
01e08737da Docs/admin-guide/mm/damon/usage: link design document for DAMOS
The background and concept of DAMOS is redundantly documented, in the
design document and the usage document.  Replace the duplicated ones in
usage document with links to the design document.

Link: https://lkml.kernel.org/r/20230616191742.87531-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:36 -07:00
SeongJae Park
ddb7d012b1 Docs/admin-guide/mm/damon/usage: remove unnecessary sentences about supported address spaces
Brief explanation of DAMON user space tool and sysfs interface are
unnecessarily and repeatedly mentioning the list of address spaces that
DAMON is supporting.  Remove those.

Link: https://lkml.kernel.org/r/20230616191742.87531-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:36 -07:00
SeongJae Park
cc5ece5979 Docs/admin-guide/mm/damon/usage: fix typos in references and commas
Fix typos including a unnecessary comma and incomplete ':ref:' keywords.

Link: https://lkml.kernel.org/r/20230616191742.87531-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:36 -07:00
SeongJae Park
60eb644b01 Docs/admin-guide/mm/damon/start: update DAMOS example command
DAMON user-space tool, damo, has deprecated[1] its old DAMOS schemes
specification format.  However, an example of DAMON documentation is still
using it.  Update the example to use one of the alternative options.

[1] https://github.com/awslabs/damo/commit/e9950ae68f6c

Link: https://lkml.kernel.org/r/20230616191742.87531-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:36 -07:00
Kefeng Wang
6c77b607ee mm: kill lock|unlock_page_memcg()
Since commit c7c3dec1c9 ("mm: rmap: remove lock_page_memcg()"),
no more user, kill lock_page_memcg() and unlock_page_memcg().

Link: https://lkml.kernel.org/r/20230614143612.62575-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:33 -07:00
Will Deacon
dea0f4146f docs: perf: Fix warning from 'make htmldocs' in hisi-pmu.rst
Building the 'htmldocs' target results in the following warning when
processing 'hisi-pmu.rst':

 | Documentation/admin-guide/perf/hisi-pmu.rst:107: ERROR: Unexpected indentation.

Fix the warning by converting all of the register bitfield lists into
proper bulleted lists and adjusting the indentation of the wrapping line
accordingly. At the same time, use an enumerated list to describe the
new PMUv2 functions.

Fixes: ea8d1c062a ("docs: perf: Add new description for HiSilicon UC PMU")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Will Deacon <will@kernel.org>
2023-06-19 11:02:18 +01:00
Joerg Roedel
a7a334076d Merge branches 'iommu/fixes', 'arm/smmu', 'ppc/pamu', 'virtio', 'x86/vt-d', 'core' and 'x86/amd' into next 2023-06-19 10:12:42 +02:00
Mikulas Patocka
4c2c845bdc dm flakey: introduce random_read_corrupt and random_write_corrupt options
The random_read_corrupt and random_write_corrupt options corrupt a
random byte in a bio with the provided probability. The corruption
only happens in the "down" interval.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-06-16 18:24:13 -04:00
Junhao He
ea8d1c062a docs: perf: Add new description for HiSilicon UC PMU
A new function is added on HiSilicon uncore UC PMU.

The UC PMU support to filter statistical information based on
the specified tx request uring channel. Make user configuration
through "uring_channel" parameter.
Document them to provide guidance on how to use them.

Signed-off-by: Junhao He <hejunhao3@huawei.com>
Reviewed-by: Jonathan Cameron <Jonthan.Cameron@huawei.com>
Reviewed-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230615125926.29832-4-hejunhao3@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
2023-06-16 12:27:38 +01:00
Jakub Kicinski
173780ff18 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

include/linux/mlx5/driver.h
  617f5db1a6 ("RDMA/mlx5: Fix affinity assignment")
  dc13180824 ("net/mlx5: Enable devlink port for embedded cpu VF vports")
https://lore.kernel.org/all/20230613125939.595e50b8@canb.auug.org.au/

tools/testing/selftests/net/mptcp/mptcp_join.sh
  47867f0a7e ("selftests: mptcp: join: skip check if MIB counter not supported")
  425ba80312 ("selftests: mptcp: join: support RM_ADDR for used endpoints or not")
  45b1a1227a ("mptcp: introduces more address related mibs")
  0639fa230a ("selftests: mptcp: add explicit check for new mibs")
https://lore.kernel.org/netdev/20230609-upstream-net-20230610-mptcp-selftests-support-old-kernels-part-3-v1-0-2896fe2ee8a3@tessares.net/

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-15 22:19:41 -07:00
Andrea Tomassetti
ccb8c3bd6d bcache: Remove dead references to cache_readaheads
The cache_readaheads stat counter is not used anymore and should be
removed.

Signed-off-by: Andrea Tomassetti <andrea.tomassetti-opensource@devo.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230615121223.22502-4-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-15 07:30:11 -06:00
Lars R. Damerow
e0e0b4126c mm/memcontrol: export memcg.swap watermark via sysfs for v2 memcg
This patch is similar to commit 8e20d4b332 ("mm/memcontrol: export
memcg->watermark via sysfs for v2 memcg"), but exports the swap counter's
watermark.

We allocate jobs to our compute farm using heuristics determined by memory
and swap usage from previous jobs.  Tracking the peak swap usage for new
jobs is important for determining when jobs are exceeding their expected
bounds, or when our baseline metrics are getting outdated.

Our toolset was written to use the "memory.memsw.max_usage_in_bytes" file
in cgroups v1, and altering it to poll cgroups v2's "memory.swap.current"
would give less accurate results as well as add complication to the code. 
Having this watermark exposed in sysfs is much preferred.

Link: https://lkml.kernel.org/r/20230524181734.125696-1-lars@pixar.com
Signed-off-by: Lars R. Damerow <lars@pixar.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:43 -07:00
Suravee Suthikulpanit
66419036f6 iommu/amd: Introduce Disable IRTE Caching Support
An Interrupt Remapping Table (IRT) stores interrupt remapping configuration
for each device. In a normal operation, the AMD IOMMU caches the table
to optimize subsequent data accesses. This requires the IOMMU driver to
invalidate IRT whenever it updates the table. The invalidation process
includes issuing an INVALIDATE_INTERRUPT_TABLE command following by
a COMPLETION_WAIT command.

However, there are cases in which the IRT is updated at a high rate.
For example, for IOMMU AVIC, the IRTE[IsRun] bit is updated on every
vcpu scheduling (i.e. amd_iommu_update_ga()). On system with large
amount of vcpus and VFIO PCI pass-through devices, the invalidation
process could potentially become a performance bottleneck.

Introducing a new kernel boot option:

    amd_iommu=irtcachedis

which disables IRTE caching by setting the IRTCachedis bit in each IOMMU
Control register, and bypass the IRT invalidation process.

Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Co-developed-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20230530141137.14376-4-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-06-09 14:47:09 +02:00
Mauro Carvalho Chehab
be9aac1874 Merge tag 'v6.4-rc5' into media_stage
Linux 6.4-rc5

* tag 'v6.4-rc5': (919 commits)
  Linux 6.4-rc5
  leds: qcom-lpg: Fix PWM period limits
  selftests/ftrace: Choose target function for filter test from samples
  KVM: selftests: Add test for race in kvm_recalculate_apic_map()
  KVM: x86: Bail from kvm_recalculate_phys_map() if x2APIC ID is out-of-bounds
  KVM: x86: Account fastpath-only VM-Exits in vCPU stats
  KVM: SVM: vNMI pending bit is V_NMI_PENDING_MASK not V_NMI_BLOCKING_MASK
  KVM: x86/mmu: Grab memslot for correct address space in NX recovery worker
  tpm, tpm_tis: correct tpm_tis_flags enumeration values
  Revert "ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits"
  media: uvcvideo: Don't expose unsupported formats to userspace
  media: v4l2-subdev: Fix missing kerneldoc for client_caps
  media: staging: media: imx: initialize hs_settle to avoid warning
  media: v4l2-mc: Drop subdev check in v4l2_create_fwnode_links_to_pad()
  riscv: Implement missing huge_ptep_get
  riscv: Fix huge_ptep_set_wrprotect when PTE is a NAPOT
  module/decompress: Fix error checking on zstd decompression
  fork, vhost: Use CLONE_THREAD to fix freezer/ps regression
  dt-bindings: serial: 8250_omap: add rs485-rts-active-high
  selinux: don't use make's grouped targets feature yet
  ...
2023-06-09 10:12:41 +01:00
Jiaxun Yang
975fd3c26f MIPS: Select CONFIG_GENERIC_IDLE_POLL_SETUP
hlt,nohlt paramaters are useful when debugging cpuidle
related issues.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2023-06-09 10:34:26 +02:00
Jiaxun Yang
96cb8ae28c MIPS: Rework smt cmdline parameters
Provide a generic smt parameters interface aligned with s390
to allow users to limit smt usage and threads per core.

It replaced previous undocumented "nothreads" parameter for
smp-cps which is ambiguous and does not cover smp-mt.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2023-06-09 10:34:14 +02:00
Linus Torvalds
9cd6357f10 Merge tag 'cgroup-for-6.4-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:

 - Fix css_set reference leaks on fork failures

 - Fix CPU hotplug locking in cgroup_transfer_tasks() which is used by
   cgroup1 cpuset

 - Doc update

* tag 'cgroup-for-6.4-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Documentation: Clarify usage of memory limits
  cgroup: always put cset in cgroup_css_set_put_fork
  cgroup: fix missing cpus_read_{lock,unlock}() in cgroup_transfer_tasks()
2023-06-08 18:52:54 -07:00
Paul E. McKenney
2e31da752c Merge branches 'doc.2023.05.10a', 'fixes.2023.05.11a', 'kvfree.2023.05.10a', 'nocb.2023.05.11a', 'rcu-tasks.2023.05.10a', 'torture.2023.05.15a' and 'rcu-urgent.2023.06.06a' into HEAD
doc.2023.05.10a: Documentation updates
fixes.2023.05.11a: Miscellaneous fixes
kvfree.2023.05.10a: kvfree_rcu updates
nocb.2023.05.11a: Callback-offloading updates
rcu-tasks.2023.05.10a: Tasks RCU updates
torture.2023.05.15a: Torture-test updates
rcu-urgent.2023.06.06a: Urgent SRCU fix
2023-06-07 13:44:06 -07:00
Hou Tao
ddf63516d8 blk-ioprio: Introduce promote-to-rt policy
Since commit a78418e6a0 ("block: Always initialize bio IO priority on
submit"), bio->bi_ioprio will never be IOPRIO_CLASS_NONE when calling
blkcg_set_ioprio(), so there will be no way to promote the io-priority
of one cgroup to IOPRIO_CLASS_RT, because bi_ioprio will always be
greater than or equals to IOPRIO_CLASS_RT.

It seems possible to call blkcg_set_ioprio() first then try to
initialize bi_ioprio later in bio_set_ioprio(), but this doesn't work
for bio in which bi_ioprio is already initialized (e.g., direct-io), so
introduce a new promote-to-rt policy to promote the iopriority of bio to
IOPRIO_CLASS_RT if the ioprio is not already RT.

For none-to-rt policy, although it doesn't work now, but considering
that its purpose was also to override the io-priority to RT and allowing
for a smoother transition, just keep it and treat it as an alias of
the promote-to-rt policy.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20230428074404.280532-1-houtao@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-06 22:26:26 -06:00
Dan Schatzberg
5647e53f78 cgroup: Documentation: Clarify usage of memory limits
The existing documentation refers to memory.high as the "main mechanism
to control memory usage." This seems incorrect to me - memory.high can
result in reclaim pressure which simply leads to stalls unless some
external component observes and actions on it (e.g. systemd-oomd can be
used for this purpose). While this is feasible, users are unaware of
this interaction and are led to believe that memory.high alone is an
effective mechanism for limiting memory.

The documentation should recommend the use of memory.max as the
effective way to enforce memory limits - it triggers reclaim and results
in OOM kills by itself.

Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-06-05 14:08:12 -10:00
Christoph Hellwig
702f3189e4 block: move the code to do early boot lookup of block devices to block/
Create a new block/early-lookup.c to keep the early block device lookup
code instead of having this code sit with the early mount code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-05 10:57:40 -06:00
Christoph Hellwig
cf056a4312 init: improve the name_to_dev_t interface
name_to_dev_t has a very misleading name, that doesn't make clear
it should only be used by the early init code, and also has a bad
calling convention that doesn't allow returning different kinds of
errors.  Rename it to early_lookup_bdev to make the use case clear,
and return an errno, where -EINVAL means the string could not be
parsed, and -ENODEV means it the string was valid, but there was
no device found for it.

Also stub out the whole call for !CONFIG_BLOCK as all the non-block
root cases are always covered in the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-14-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-05 10:56:46 -06:00
Christoph Hellwig
c0c1a7dcb6 init: move the nfs/cifs/ram special cases out of name_to_dev_t
The nfs/cifs/ram special case only needs to be parsed once, and only in
the boot code.  Move them out of name_to_dev_t and into
prepare_namespace.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-05 10:55:20 -06:00
Kristina Martsenko
3e1dedb29d arm64: mops: allow disabling MOPS from the kernel command line
Make it possible to disable the MOPS extension at runtime using the
kernel command line. This can be useful for testing or working around
hardware issues. For example it could be used to test new memory copy
routines that do not use MOPS instructions (e.g. from Arm Optimized
Routines).

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20230509142235.3284028-11-kristina.martsenko@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-06-05 17:05:42 +01:00
Jakub Kicinski
a03a91bd68 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/sfc/tc.c
  622ab65634 ("sfc: fix error unwinds in TC offload")
  b6583d5e9e ("sfc: support TC decap rules matching on enc_src_port")

net/mptcp/protocol.c
  5b825727d0 ("mptcp: add annotations around msk->subflow accesses")
  e76c8ef5cc ("mptcp: refactor mptcp_stream_accept()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-01 15:38:26 -07:00
Sunil V L
724f4c0df7 RISC-V: Add ACPI initialization in setup_arch()
Initialize the ACPI core for RISC-V during boot.

ACPI tables and interpreter are initialized based on
the information passed from the firmware and the value of
the kernel parameter 'acpi'.

With ACPI support added for RISC-V, the kernel parameter 'acpi'
is also supported on RISC-V. Hence, update the documentation.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230515054928.2079268-9-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-01 08:45:03 -07:00
Juergen Gross
a431660353 x86/mtrr: Add mtrr=debug command line option
Add a new command line option "mtrr=debug" for getting debug output
after building the new cache mode map. The output will include MTRR
register values and the resulting map.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230502120931.20719-13-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2023-06-01 15:04:33 +02:00
Jakub Kicinski
d6f1e0bfe5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-25 20:56:43 -07:00
Jack Zhu
a73206f33b media: admin-guide: Update rkisp1.rst
Update Rockchip ISP1 driver file path

Signed-off-by: Jack Zhu <jack.zhu@starfivetech.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
2023-05-25 16:21:21 +02:00
Antoine Tenart
7016eb7386 Documentation: net: net.core.txrehash is not specific to listening sockets
The net.core.txrehash documentation mentions this knob is for listening
sockets only, while sk_rethink_txhash can be called on SYN and RTO
retransmits on all TCP sockets.

Remove the listening socket part.

Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-05-25 13:20:45 +02:00
Steve French
bf8a352d49 cifs: correct references in Documentation to old fs/cifs path
The fs/cifs directory has moved to fs/smb/client, correct mentions
of this in Documentation and comments.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-24 16:29:21 -05:00
Yan-Jie Wang
f41dd67da6 docs: clarify KVM related kernel parameters' descriptions
The descriptions of certain KVM related kernel parameters can be
confusing. They state "Disable ...," which may make people think that
setting them to 1 will disable the associated feature when in fact the
opposite is true.

This commit addresses this issue by revising the descriptions of these
parameters by using "Control..." rather than "Enable/Disable...".
1==enabled or 0==disabled can be communicated by the description of
default value such as "1 (enabled)" or "0 (disabled)".

Also update the description of KVM's default value for kvm-intel.nested
as it is enabled by default.

Signed-off-by: Yan-Jie Wang <yanjiewtw@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230503081530.19956-1-yanjiewtw@gmail.com
2023-05-19 08:56:30 -06:00
Natesh Sharma
f02c20d9f1 docs: admin-guide: Add information about intel_pstate active mode
Information about intel_pstate active mode is added in the doc.
This operation mode could be used to set on the hardware when it's
not activated. Status of the mode could be checked from sysfs file
i.e., /sys/devices/system/cpu/intel_pstate/status.
The information is already available in cpu-freq/intel-pstate.txt
documentation.

Signed-off-by: Natesh Sharma <nsharma@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
[jc: reformatted for width ]
Link: https://lore.kernel.org/r/20230427083706.49882-1-nsharma@redhat.com
2023-05-19 08:33:27 -06:00
Tejun Heo
6363845005 workqueue: Report work funcs that trigger automatic CPU_INTENSIVE mechanism
Workqueue now automatically marks per-cpu work items that hog CPU for too
long as CPU_INTENSIVE, which excludes them from concurrency management and
prevents stalling other concurrency-managed work items. If a work function
keeps running over the thershold, it likely needs to be switched to use an
unbound workqueue.

This patch adds a debug mechanism which tracks the work functions which
trigger the automatic CPU_INTENSIVE mechanism and report them using
pr_warn() with exponential backoff.

v3: Documentation update.

v2: Drop bouncing to kthread_worker for printing messages. It was to avoid
    introducing circular locking dependency through printk but not effective
    as it still had pool lock -> wci_lock -> printk -> pool lock loop. Let's
    just print directly using printk_deferred().

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
2023-05-17 17:02:08 -10:00
Tejun Heo
616db8779b workqueue: Automatically mark CPU-hogging work items CPU_INTENSIVE
If a per-cpu work item hogs the CPU, it can prevent other work items from
starting through concurrency management. A per-cpu workqueue which intends
to host such CPU-hogging work items can choose to not participate in
concurrency management by setting %WQ_CPU_INTENSIVE; however, this can be
error-prone and difficult to debug when missed.

This patch adds an automatic CPU usage based detection. If a
concurrency-managed work item consumes more CPU time than the threshold
(10ms by default) continuously without intervening sleeps, wq_worker_tick()
which is called from scheduler_tick() will detect the condition and
automatically mark it CPU_INTENSIVE.

The mechanism isn't foolproof:

* Detection depends on tick hitting the work item. Getting preempted at the
  right timings may allow a violating work item to evade detection at least
  temporarily.

* nohz_full CPUs may not be running ticks and thus can fail detection.

* Even when detection is working, the 10ms detection delays can add up if
  many CPU-hogging work items are queued at the same time.

However, in vast majority of cases, this should be able to detect violations
reliably and provide reasonable protection with a small increase in code
complexity.

If some work items trigger this condition repeatedly, the bigger problem
likely is the CPU being saturated with such per-cpu work items and the
solution would be making them UNBOUND. The next patch will add a debug
mechanism to help spot such cases.

v4: Documentation for workqueue.cpu_intensive_thresh_us added to
    kernel-parameters.txt.

v3: Switch to use wq_worker_tick() instead of hooking into preemptions as
    suggested by Peter.

v2: Lai pointed out that wq_worker_stopping() also needs to be called from
    preemption and rtlock paths and an earlier patch was updated
    accordingly. This patch adds a comment describing the risk of infinte
    recursions and how they're avoided.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
2023-05-17 17:02:08 -10:00
Thorsten Leemhuis
0d8aa3212e docs: quickly-build-trimmed-linux: various small fixes and improvements
* improve the short description of localmodconfig in the step-by-step
  guide while fixing its broken first sentence

* briefly mention immutable Linux distributions

* use '--shallow-exclude=v6.0' throughout the document

* instead of "git reset --hard; git checkout ..." use "git checkout
  --force ..." in the step-by-step guide: this matches the TLDR and is
  one command less to execute. This led to a few small adjustments to
  the text and the flow in the surrounding area.

* fix two thinkos in the section explaining full git clones

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/6f4684b9a5d11d3adb04e0af3cfc60db8b28eeb2.1684140700.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-05-16 12:50:05 -06:00
Josh Poimboeuf
89da5a69a8 x86/unwind/orc: Add 'unwind_debug' cmdline option
Sometimes the one-line ORC unwinder warnings aren't very helpful.  Add a
new 'unwind_debug' cmdline option which will dump the full stack
contents of the current task when an error condition is encountered.

Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/6afb9e48a05fd2046bfad47e69b061b43dfd0e0e.1681331449.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-05-16 06:31:50 -07:00
Zqiang
9e5d61c013 doc/rcutorture: Add description of rcutorture.stall_cpu_block
If you build a kernel with CONFIG_PREEMPTION=n and CONFIG_PREEMPT_COUNT=y,
then run the rcutorture tests specifying stalls as follows:

runqemu kvm slirp nographic qemuparams="-m 1024 -smp 4" \
	bootparams="console=ttyS0 rcutorture.stall_cpu=30 \
	rcutorture.stall_no_softlockup=1 rcutorture.stall_cpu_block=1" -d

The tests will produce the following splat:

[   10.841071] rcu-torture: rcu_torture_stall begin CPU stall
[   10.841073] rcu_torture_stall start on CPU 3.
[   10.841077] BUG: scheduling while atomic: rcu_torture_sta/66/0x0000000
....
[   10.841108] Call Trace:
[   10.841110]  <TASK>
[   10.841112]  dump_stack_lvl+0x64/0xb0
[   10.841118]  dump_stack+0x10/0x20
[   10.841121]  __schedule_bug+0x8b/0xb0
[   10.841126]  __schedule+0x2172/0x2940
[   10.841157]  schedule+0x9b/0x150
[   10.841160]  schedule_timeout+0x2e8/0x4f0
[   10.841192]  schedule_timeout_uninterruptible+0x47/0x50
[   10.841195]  rcu_torture_stall+0x2e8/0x300
[   10.841199]  kthread+0x175/0x1a0
[   10.841206]  ret_from_fork+0x2c/0x50

This is because the rcutorture.stall_cpu_block=1 module parameter causes
rcu_torture_stall() to invoke schedule_timeout_uninterruptible() within
an RCU read-side critical section.  This in turn results in a quiescent
state (which prevents the stall) and a sleep in an atomic context (which
produces the above splat).

Although this code is operating as designed, the design has proven to
be counterintuitive to many.  This commit therefore updates the description
in kernel-parameters.txt accordingly.

[ paulmck: Apply Joel Fernandes feedback. ]

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-05-15 12:23:22 -07:00
Thomas Gleixner
18415f33e2 cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE
There is often significant latency in the early stages of CPU bringup, and
time is wasted by waking each CPU (e.g. with SIPI/INIT/INIT on x86) and
then waiting for it to respond before moving on to the next.

Allow a platform to enable parallel setup which brings all to be onlined
CPUs up to the CPUHP_BP_KICK_AP state. While this state advancement on the
control CPU (BP) is single-threaded the important part is the last state
CPUHP_BP_KICK_AP which wakes the to be onlined CPUs up.

This allows the CPUs to run up to the first sychronization point
cpuhp_ap_sync_alive() where they wait for the control CPU to release them
one by one for the full onlining procedure.

This parallelism depends on the CPU hotplug core sync mechanism which
ensures that the parallel brought up CPUs wait for release before touching
any state which would make the CPU visible to anything outside the hotplug
control mechanism.

To handle the SMT constraints of X86 correctly the bringup happens in two
iterations when CONFIG_HOTPLUG_SMT is enabled. The control CPU brings up
the primary SMT threads of each core first, which can load the microcode
without the need to rendevouz with the thread siblings. Once that's
completed it brings up the secondary SMT threads.

Co-developed-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://lore.kernel.org/r/20230512205257.240231377@linutronix.de
2023-05-15 13:45:02 +02:00
Thomas Gleixner
e59e74dc48 x86/topology: Remove CPU0 hotplug option
This was introduced together with commit e1c467e690 ("x86, hotplug: Wake
up CPU0 via NMI instead of INIT, SIPI, SIPI") to eventually support
physical hotplug of CPU0:

 "We'll change this code in the future to wake up hard offlined CPU0 if
  real platform and request are available."

11 years later this has not happened and physical hotplug is not officially
supported. Remove the cruft.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://lore.kernel.org/r/20230512205255.715707999@linutronix.de
2023-05-15 13:44:49 +02:00
Paul E. McKenney
fb6112497b doc: Document the rcutree.rcu_resched_ns module parameter
This commit adds kernel-parameters.txt documentation for the
rcutree.rcu_resched_ns module parameter.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-05-09 17:24:20 -07:00
Paul E. McKenney
51823ca651 doc: Get rcutree module parameters back into alpha order
This commit puts the rcutree module parameters back into proper
alphabetical order.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2023-05-09 17:24:20 -07:00
Srinivas Pandruvada
9b8dea80e3 platform/x86/intel-uncore-freq: Support for cluster level controls
An SoC can contain multiple power domains with individual or collection
of mesh partitions. This partition is called fabric cluster.

Certain type of meshes will need to run at the same frequency, they will
be placed in the same fabric cluster. Benefit of fabric cluster is that
it offers a scalable mechanism to deal with partitioned fabrics in a SoC.

The current sysfs interface supports control at package and die level.
This interface is not enough to support more granular control at
fabric cluster level.

SoCs with the support of TPMI (Topology Aware Register and PM Capsule
Interface), can have multiple power domains. Each power domain can
contain one or more fabric clusters.

To support such granular controls, enhance uncore common to optionally
create new directories to provide controls at fabric cluster level. It
is also important to have flexibility to change granularity for future
version of SoCs. If the directory name contains scope like:
"package_*_die_*_power_domain_*_cluster_*", then this is not expandable.

The cpufreq policies also have different scopes. There the scope of the
policy (affected_cpus) specified by attributes inside each policy.
So, follow the same model for uncore frequency scaling sysfs as:
"sys/devices/system/cpu/cpufreq/policy*"

Allow client drivers to optionally support granular control for each
fabric cluster. Here, the directory name will be "uncore" suffixed with
an unique instance number. For example: uncore00, uncore01 etc.
Attributes in the directory identify package id, power domain and
fabric cluster id. This interface is expandable even if some new level
of granularity is introduced. A new sysfs attribute can identify new
level.

For compatibility with the existing sysfs and provide easy way to set
limits for each fabric cluster in the package/die, the existing control
at package/die levels are still provided. For majority of users, this is
an easy approach.

For example: On a single package/die system, with three power domains
and one fabric cluster per power domain:

$tree -L 2 /sys/devices/system/cpu/intel_uncore_frequency/
/sys/devices/system/cpu/intel_uncore_frequency/
├── package_00_die_00
│   ├── current_freq_khz
│   ├── initial_max_freq_khz
│   ├── initial_min_freq_khz
│   ├── max_freq_khz
│   └── min_freq_khz
├── uncore00
│   ├── current_freq_khz
│   ├── domain_id
│   ├── fabric_cluster_id
│   ├── initial_max_freq_khz
│   ├── initial_min_freq_khz
│   ├── max_freq_khz
│   ├── min_freq_khz
│   └── package_id
├── uncore01
│   ├── current_freq_khz
│   ├── domain_id
│   ├── fabric_cluster_id
│   ├── initial_max_freq_khz
│   ├── initial_min_freq_khz
│   ├── max_freq_khz
│   ├── min_freq_khz
│   └── package_id
└── uncore02
    ├── current_freq_khz
    ├── domain_id
    ├── fabric_cluster_id
    ├── initial_max_freq_khz
    ├── initial_min_freq_khz
    ├── max_freq_khz
    ├── min_freq_khz
    └── package_id

The attribute for cluster id is "fabric_cluster_id" instead of just
"cluster_id" is to avoid confusion with usage of term clusters in
other part of the Linux kernel.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wendy Wang <wendy.wang@intel.com>
Link: https://lore.kernel.org/r/20230418171340.681662-3-srinivas.pandruvada@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2023-05-09 11:54:42 +02:00
Linus Torvalds
a3b111b046 Merge tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux
Pull more block updates from Jens Axboe:

 - MD pull request via Song:
      - Improve raid5 sequential IO performance on spinning disks, which
        fixes a regression since v6.0 (Jan Kara)
      - Fix bitmap offset types, which fixes an issue introduced in this
        merge window (Jonathan Derrick)

 - Cleanup of hweight type used for cgroup writeback (Maxim)

 - Fix a regression with the "has_submit_bio" changes across partitions
   (Ming)

 - Cleanup of QUEUE_FLAG_ADD_RANDOM clearing.

   We used to set this flag on queues non blk-mq queues, and hence some
   drivers clear it unconditionally. Since all of these have since been
   converted to true blk-mq drivers, drop the useless clear as the bit
   is not set (Chaitanya)

 - Fix the flags being set in a bio for a flush for drbd (Christoph)

 - Cleanup and deduplication of the code handling setting block device
   capacity (Damien)

 - Fix for ublk handling IO timeouts (Ming)

 - Fix for a regression in blk-cgroup teardown (Tao)

 - NBD documentation and code fixes (Eric)

 - Convert blk-integrity to using device_attributes rather than a second
   kobject to manage lifetimes (Thomas)

* tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux:
  ublk: add timeout handler
  drbd: correctly submit flush bio on barrier
  mailmap: add mailmap entries for Jens Axboe
  block: Skip destroyed blkg when restart in blkg_destroy_all()
  writeback: fix call of incorrect macro
  md: Fix bitmap offset type in sb writer
  md/raid5: Improve performance for sequential IO
  docs nbd: userspace NBD now favors github over sourceforge
  block nbd: use req.cookie instead of req.handle
  uapi nbd: add cookie alias to handle
  uapi nbd: improve doc links to userspace spec
  blk-integrity: register sysfs attributes on struct device
  blk-integrity: convert to struct device_attribute
  blk-integrity: use sysfs_emit
  block/drivers: remove dead clear of random flag
  block: sync part's ->bd_has_submit_bio with disk's
  block: Cleanup set_capacity()/bdev_set_nr_sectors()
2023-05-06 08:28:58 -07:00
Linus Torvalds
647681bfa6 Merge tag 'docs-6.4-2' of git://git.lwn.net/linux
Pull more documentation updates from Jonathan Corbet:
 "A handful of late-arriving documentation fixes, plus one Spanish
  translation that has been ready for some time but got applied late"

* tag 'docs-6.4-2' of git://git.lwn.net/linux:
  docs/sp_SP: Add translation of process/adding-syscalls
  CREDITS: Update email address for Mat Martineau
  Documentation: update kernel stack for x86_64
  docs: Remove unnecessary unicode character
  docs: fix "Reviewd" typo
  Documentation: timers: hrtimers: Make hybrid union historical
  docs/admin-guide/mm/ksm.rst fix intraface -> interface typo
  doc:it_IT: fix some typos
2023-05-05 13:16:42 -07:00
Linus Torvalds
56c455b38d Merge tag 'xfs-6.4-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Dave Chinner:
 "This consists mainly of online scrub functionality and the design
  documentation for the upcoming online repair functionality built on
  top of the scrub code:

   - Added detailed design documentation for the upcoming online repair
     feature

   - major update to online scrub to complete the reverse mapping
     cross-referencing infrastructure enabling us to fully validate
     allocated metadata against owner records. This is the last piece of
     scrub infrastructure needed before we can start merging online
     repair functionality.

   - Fixes for the ascii-ci hashing issues

   - deprecation of the ascii-ci functionality

   - on-disk format verification bug fixes

   - various random bug fixes for syzbot and other bug reports"

* tag 'xfs-6.4-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (107 commits)
  xfs: fix livelock in delayed allocation at ENOSPC
  xfs: Extend table marker on deprecated mount options table
  xfs: fix duplicate includes
  xfs: fix BUG_ON in xfs_getbmap()
  xfs: verify buffer contents when we skip log replay
  xfs: _{attr,data}_map_shared should take ILOCK_EXCL until iread_extents is completely done
  xfs: remove WARN when dquot cache insertion fails
  xfs: don't consider future format versions valid
  xfs: deprecate the ascii-ci feature
  xfs: test the ascii case-insensitive hash
  xfs: stabilize the dirent name transformation function used for ascii-ci dir hash computation
  xfs: cross-reference rmap records with refcount btrees
  xfs: cross-reference rmap records with inode btrees
  xfs: cross-reference rmap records with free space btrees
  xfs: cross-reference rmap records with ag btrees
  xfs: introduce bitmap type for AG blocks
  xfs: convert xbitmap to interval tree
  xfs: drop the _safe behavior from the xbitmap foreach macro
  xfs: don't load local xattr values during scrub
  xfs: remove the for_each_xbitmap_ helpers
  ...
2023-04-29 10:44:27 -07:00
Linus Torvalds
86e98ed15b Merge tag 'cgroup-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:

 - cpuset changes including the fix for an incorrect interaction with
   CPU hotplug and an optimization

 - Other doc and cosmetic changes

* tag 'cgroup-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  docs: cgroup-v1/cpusets: update libcgroup project link
  cgroup/cpuset: Minor updates to test_cpuset_prs.sh
  cgroup/cpuset: Include offline CPUs when tasks' cpumasks in top_cpuset are updated
  cgroup/cpuset: Skip task update if hotplug doesn't affect current cpuset
  cpuset: Clean up cpuset_node_allowed
  cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers
2023-04-29 10:05:22 -07:00