Commit Graph

3216 Commits

Author SHA1 Message Date
SeongJae Park
57e88e86a1 Docs/admin-guide/mm/damon/usage: document quota goal metric file
Update DAMON usage document for the quota goal target_metric file.

[sj@kernel.org: fix a typo on the auto-tuning design reference link]
  Link: https://lkml.kernel.org/r/20240221170852.55529-3-sj@kernel.org
Link: https://lkml.kernel.org/r/20240219194431.159606-18-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23 17:48:29 -08:00
SeongJae Park
a6068d6dfa Docs/admin-guide/mm/damon/usage: document effective_bytes file
Update DAMON usage document for the effective quota file of the DAMON
sysfs interface.

Link: https://lkml.kernel.org/r/20240219194431.159606-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23 17:48:26 -08:00
Baoquan He
55c49fee57 mm/vmalloc: remove vmap_area_list
Earlier, vmap_area_list is exported to vmcoreinfo so that makedumpfile get
the base address of vmalloc area.  Now, vmap_area_list is empty, so export
VMALLOC_START to vmcoreinfo instead, and remove vmap_area_list.

[urezki@gmail.com: fix a warning in the crash_save_vmcoreinfo_init()]
  Link: https://lkml.kernel.org/r/20240111192329.449189-1-urezki@gmail.com
Link: https://lkml.kernel.org/r/20240102184633.748113-6-urezki@gmail.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Kazuhito Hagio <k-hagio-ab@nec.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23 17:48:19 -08:00
Feng Tang
2e3fc6ca52 panic: add option to dump blocked tasks in panic_print
For debugging kernel panics and other bugs, there is already an option of
panic_print to dump all tasks' call stacks.  On today's large servers
running many containers, there could be thousands of tasks or more, and
this will print out huge amount of call stacks, taking a lot of time (for
serial console which is main target user case of panic_print).

And in many cases, only those several tasks being blocked are key for the
panic, so add an option to only dump blocked tasks' call stacks.

[akpm@linux-foundation.org: clarify documentation a little]
Link: https://lkml.kernel.org/r/20240202132042.3609657-1-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:38:55 -08:00
Alexey Gladkov
9220066ea8 docs: add information about ipc sysctls limitations
After 25b21cb2f6 ("[PATCH] IPC namespace core") and 4e9823111b
("[PATCH] IPC namespace - shm") the shared memory page count stopped being
global and started counting per ipc namespace.  The documentation and
shmget(2) still says that shmall is a global option.

shmget(2):

SHMALL System-wide limit on the total amount of shared memory, measured in
units of the system page size.  On Linux, this limit can be read and
modified via /proc/sys/kernel/shmall.

I think the changes made in 2006 should be documented.

Link: https://lkml.kernel.org/r/09e99911071766958af488beb4e8a728a4f12135.1705333426.git.legion@kernel.org
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lkml.kernel.org/r/ede20ddf7be48b93e8084c3be2e920841ee1a641.1663756794.git.legion@kernel.org
Cc: Christian Brauner <brauner@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Joel Granados <joel.granados@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:38:52 -08:00
SeongJae Park
7d8cebb963 Docs/admin-guide/mm/damon/usage: fix wrong quotas diabling condition
After the introduction of DAMOS quotas, DAMOS quotas is not disabled if
both size and time quotas are zero but the quota goal is set.  The new
rule is also applied to DAMON sysfs interface, but the usage doc is not
updated.  Update it.

Link: https://lkml.kernel.org/r/20240217005842.87348-6-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>
2024-02-22 15:27:20 -08:00
SeongJae Park
2d89957c93 Docs/mm/damon: move monitoring target regions setup detail from the usage to the design document
Design doc is aimed to have all concept level details, while the usage doc
is focused on only how the features can be used.  Some details about
monitoring target regions construction is on the usage doc.  Move the
details about the monitoring target regions construction differences for
DAMON operations set from the usage to the design doc.

Link: https://lkml.kernel.org/r/20240217005842.87348-5-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>
2024-02-22 15:27:20 -08:00
SeongJae Park
669971b406 Docs/mm/damon: move DAMON operation sets list from the usage to the design document
The list of DAMON operation sets and their explanation, which may better
to be on design document, is written on the usage document.  Move the
detail to design document and make the usage document only reference the
design document.

[sj@kernel.org: fix a typo on a reference link]
  Link: https://lkml.kernel.org/r/20240221170852.55529-2-sj@kernel.org
Link: https://lkml.kernel.org/r/20240217005842.87348-4-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>
2024-02-22 15:27:20 -08:00
SeongJae Park
5b7708e6a8 Docs/mm/damon: move the list of DAMOS actions to design doc
DAMOS operation actions are explained nearly twice on the DAMON usage
document, once for the sysfs interface, and then again for the debugfs
interface.  Duplication is bad.  Also it would better to keep this kind of
concept level details in design document and keep the usage document small
and focus on only the usage.  Move the list to design document and update
usage document to reference it.

Link: https://lkml.kernel.org/r/20240217005842.87348-3-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>
2024-02-22 15:27:20 -08:00
Nikhil V
3fec6e5961 PM: hibernate: Support to select compression algorithm
Currently the default compression algorithm is selected based on
compile time options. Introduce a module parameter "hibernate.compressor"
to override this behaviour.

Different compression algorithms have different characteristics and
hibernation may benefit when it uses any of these algorithms, especially
when a secondary algorithm(LZ4) offers better decompression speeds over
a default algorithm(LZO), which in turn reduces hibernation image
restore time.

Users can override the default algorithm in two ways:

 1) Passing "hibernate.compressor" as kernel command line parameter.
    Usage:
    	LZO: hibernate.compressor=lzo
    	LZ4: hibernate.compressor=lz4

 2) Specifying the algorithm at runtime.
    Usage:
	LZO: echo lzo > /sys/module/hibernate/parameters/compressor
	LZ4: echo lz4 > /sys/module/hibernate/parameters/compressor

Currently LZO and LZ4 are the supported algorithms. LZO is the default
compression algorithm used with hibernation.

Signed-off-by: Nikhil V <quic_nprakash@quicinc.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-02-22 20:03:21 +01:00
Gregory Price
fa3bea4e1f mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted interleaving
When a system has multiple NUMA nodes and it becomes bandwidth hungry,
using the current MPOL_INTERLEAVE could be an wise option.

However, if those NUMA nodes consist of different types of memory such as
socket-attached DRAM and CXL/PCIe attached DRAM, the round-robin based
interleave policy does not optimally distribute data to make use of their
different bandwidth characteristics.

Instead, interleave is more effective when the allocation policy follows
each NUMA nodes' bandwidth weight rather than a simple 1:1 distribution.

This patch introduces a new memory policy, MPOL_WEIGHTED_INTERLEAVE,
enabling weighted interleave between NUMA nodes.  Weighted interleave
allows for proportional distribution of memory across multiple numa nodes,
preferably apportioned to match the bandwidth of each node.

For example, if a system has 1 CPU node (0), and 2 memory nodes (0,1),
with bandwidth of (100GB/s, 50GB/s) respectively, the appropriate weight
distribution is (2:1).

Weights for each node can be assigned via the new sysfs extension:
/sys/kernel/mm/mempolicy/weighted_interleave/

For now, the default value of all nodes will be `1`, which matches the
behavior of standard 1:1 round-robin interleave.  An extension will be
added in the future to allow default values to be registered at kernel and
device bringup time.

The policy allocates a number of pages equal to the set weights.  For
example, if the weights are (2,1), then 2 pages will be allocated on node0
for every 1 page allocated on node1.

The new flag MPOL_WEIGHTED_INTERLEAVE can be used in set_mempolicy(2)
and mbind(2).

Some high level notes about the pieces of weighted interleave:

current->il_prev:
    Tracks the node previously allocated from.

current->il_weight:
    The active weight of the current node (current->il_prev)
    When this reaches 0, current->il_prev is set to the next node
    and current->il_weight is set to the next weight.

weighted_interleave_nodes:
    Counts the number of allocations as they occur, and applies the
    weight for the current node.  When the weight reaches 0, switch
    to the next node.  Operates only on task->mempolicy.

weighted_interleave_nid:
    Gets the total weight of the nodemask as well as each individual
    node weight, then calculates the node based on the given index.
    Operates on VMA policies.

bulk_array_weighted_interleave:
    Gets the total weight of the nodemask as well as each individual
    node weight, then calculates the number of "interleave rounds" as
    well as any delta ("partial round").  Calculates the number of
    pages for each node and allocates them.

    If a node was scheduled for interleave via interleave_nodes, the
    current weight will be allocated first.

    Operates only on the task->mempolicy.

One piece of complexity is the interaction between a recent refactor which
split the logic to acquire the "ilx" (interleave index) of an allocation
and the actually application of the interleave.  If a call to
alloc_pages_mpol() were made with a weighted-interleave policy and ilx set
to NO_INTERLEAVE_INDEX, weighted_interleave_nodes() would operate on a VMA
policy - violating the description above.

An inspection of all callers of alloc_pages_mpol() shows that all external
callers set ilx to `0`, an index value, or will call get_vma_policy() to
acquire the ilx.

For example, mm/shmem.c may call into alloc_pages_mpol.  The call stacks
all set (pgoff_t ilx) or end up in `get_vma_policy()`.  This enforces the
`weighted_interleave_nodes()` and `weighted_interleave_nid()` policy
requirements (task/vma respectively).

Link: https://lkml.kernel.org/r/20240202170238.90004-4-gregory.price@memverge.com
Suggested-by: Hasan Al Maruf <Hasan.Maruf@amd.com>
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Co-developed-by: Rakie Kim <rakie.kim@sk.com>
Signed-off-by: Rakie Kim <rakie.kim@sk.com>
Co-developed-by: Honggyu Kim <honggyu.kim@sk.com>
Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
Co-developed-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Co-developed-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>
Signed-off-by: Srinivasulu Thanneeru <sthanneeru.opensrc@micron.com>
Co-developed-by: Ravi Jonnalagadda <ravis.opensrc@micron.com>
Signed-off-by: Ravi Jonnalagadda <ravis.opensrc@micron.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 10:24:46 -08:00
SeongJae Park
ec28cf530c Docs/admin-guide/mm/damon/usage: update for monitor_on renaming
Update DAMON debugfs interface sections on the usage document to reflect
the fact that 'monitor_on' file has renamed to 'monitor_on_DEPRECATED'.

Link: https://lkml.kernel.org/r/20240130013549.89538-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 10:24:46 -08:00
SeongJae Park
cf3810cc31 Docs/admin-guide/mm/damon/usage: document 'DEPRECATED' file of DAMON debugfs interface
Document the newly added DAMON debugfs interface deprecation notice file
on the usage document.

Link: https://lkml.kernel.org/r/20240130013549.89538-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 10:24:45 -08:00
SeongJae Park
5af28560fe Docs/admin-guide/mm/damon/usage: use sysfs interface for tracepoints example
Patch series "mm/damon: make DAMON debugfs interface deprecation
unignorable".

DAMON debugfs interface is deprecated in February 2023, by commit
5445fcbc4c ("Docs/admin-guide/mm/damon/usage: add DAMON debugfs
interface deprecation notice").  Make the fact unable to be easily ignored
by removing an example usage from the document (patch 1), renaming the
config (patch 2), adding a deprecation notice file to the debugfs
directory (patches 3-5), and renaming the debugfs file that essnetial to
be used for real use of DAMON (patches 6-9).


This patch (of 9):

DAMON tracepoints example on the DAMON usage document is using DAMON
debugfs interface, which is deprecated.  Use its alternative, DAMON sysfs
interface.

Link: https://lkml.kernel.org/r/20240130013549.89538-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20240130013549.89538-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 10:24:45 -08:00
Xuewen Yan
ccdec92198 workqueue: Control intensive warning threshold through cmdline
When CONFIG_WQ_CPU_INTENSIVE_REPORT is set, the kernel will report
the work functions which violate the intensive_threshold_us repeatedly.
And now, only when the violate times exceed 4 and is a power of 2,
the kernel warning could be triggered.

However, sometimes, even if a long work execution time occurs only once,
it may cause other work to be delayed for a long time. This may also
cause some problems sometimes.

In order to freely control the threshold of warninging, a boot argument
is added so that the user can control the warning threshold to be printed.
At the same time, keep the exponential backoff to prevent reporting too much.

By default, the warning threshold is 4.

tj: Updated kernel-parameters.txt description.

Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-02-22 07:50:45 -10:00
Carlos Bilbao
23764f18f7 docs: Correct formatting of title in admin-guide/index.rst
Adjust the title of "The Linux kernel user's and administrator's guide" to
adhere to the expected reStructuredText (rst) formatting, using double
equal signs for the main header.

Signed-off-by: Carlos Bilbao <carlos.bilbao@amd.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240109155643.3489369-2-carlos.bilbao@amd.com
2024-02-21 13:44:21 -07:00
Feng Tang
2ed08e4bc5 clocksource: Scale the watchdog read retries automatically
On a 8-socket server the TSC is wrongly marked as 'unstable' and disabled
during boot time on about one out of 120 boot attempts:

    clocksource: timekeeping watchdog on CPU227: wd-tsc-wd excessive read-back delay of 153560ns vs. limit of 125000ns,
    wd-wd read-back delay only 11440ns, attempt 3, marking tsc unstable
    tsc: Marking TSC unstable due to clocksource watchdog
    TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
    sched_clock: Marking unstable (119294969739, 159204297)<-(125446229205, -5992055152)
    clocksource: Checking clocksource tsc synchronization from CPU 319 to CPUs 0,99,136,180,210,542,601,896.
    clocksource: Switched to clocksource hpet

The reason is that for platform with a large number of CPUs, there are
sporadic big or huge read latencies while reading the watchog/clocksource
during boot or when system is under stress work load, and the frequency and
maximum value of the latency goes up with the number of online CPUs.

The cCurrent code already has logic to detect and filter such high latency
case by reading the watchdog twice and checking the two deltas. Due to the
randomness of the latency, there is a low probabilty that the first delta
(latency) is big, but the second delta is small and looks valid. The
watchdog code retries the readouts by default twice, which is not
necessarily sufficient for systems with a large number of CPUs.

There is a command line parameter 'max_cswd_read_retries' which allows to
increase the number of retries, but that's not user friendly as it needs to
be tweaked per system. As the number of required retries is proportional to
the number of online CPUs, this parameter can be calculated at runtime.

Scale and enlarge the number of retries according to the number of online
CPUs and remove the command line parameter completely.

[ tglx: Massaged change log and comments ]

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jin Wang <jin1.wang@intel.com>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240221060859.1027450-1-feng.tang@intel.com
2024-02-21 12:00:42 +01:00
Matthew Sakai
512039b41b dm vdo: add vio life cycle details to design doc
Add more documentation details for most aspects of the data_vio
read and write processes. Also correct a few minor errors and
rewrite some text for clarity.

Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2024-02-20 13:43:18 -05:00
Matthew Sakai
a03652238d dm vdo: add vdo documentation to device-mapper index
Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2024-02-20 13:43:18 -05:00
Matthew Sakai
04bf7ac646 dm: add documentation for dm-vdo target
This adds the admin-guide documentation for dm-vdo.

vdo.rst is the guide to using dm-vdo. vdo-design is an overview of the
design of dm-vdo.

Co-developed-by: J. corwin Coburn <corwin@hurlbutnet.net>
Signed-off-by: J. corwin Coburn <corwin@hurlbutnet.net>
Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2024-02-20 13:43:13 -05:00
Detlev Casanova
ce7e79acb6 doc: media: visl: Document tpg_verbose parameter
Also document stable frames and what it means for testing tools.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil: add media: prefix to Subject]
2024-02-16 11:46:33 +01:00
Thomas Gleixner
5c5682b9f8 x86/cpu: Detect real BSP on crash kernels
When a kdump kernel is started from a crashing CPU then there is no
guarantee that this CPU is the real boot CPU (BSP). If the kdump kernel
tries to online the BSP then the INIT sequence will reset the machine.

There is a command line option to prevent this, but in case of nested kdump
kernels this is wrong.

But that command line option is not required at all because the real
BSP is enumerated as the first CPU by firmware. Support for the only
known system which was different (Voyager) got removed long ago.

Detect whether the boot CPU APIC ID is the first APIC ID enumerated by
the firmware. If the first APIC ID enumerated is not matching the boot
CPU APIC ID then skip registering it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.348542071@linutronix.de
2024-02-15 22:07:43 +01:00
Hunter Chasens
3a5f1c3d83 docs: admin-guide: Update bootloader and installation instructions
Updates the bootloader and installation instructions in
admin-guide/README.rst to align with modern practices.

Details of Changes:

 - Added guidance on using EFISTUB for UEFI/EFI systems.
 - Noted that LILO is no longer in active development and provides
   alternatives.
 - Kept LILO instructions but marked as Legacy LILO Instructions.
   Suggest removal in future patch.

Signed-off-by: Hunter Chasens <hunter.chasens18@ncf.edu>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
[jc: repaired added whitespace warnings]
Link: https://lore.kernel.org/r/20240207171007.45405-1-hunter.chasens18@ncf.edu
2024-02-14 15:46:34 -07:00
Borislav Petkov (AMD)
0e4fd816b0 Documentation: Move RAS section to admin-guide
This is where this stuff should be.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/87a5pes8jy.fsf@meer.lwn.net
2024-02-14 17:10:06 +01:00
Qais Yousef
7f66f099de rcu: Provide a boot time parameter to control lazy RCU
To allow more flexible arrangements while still provide a single kernel
for distros, provide a boot time parameter to enable/disable lazy RCU.

Specify:

	rcutree.enable_rcu_lazy=[y|1|n|0]

Which also requires

	rcu_nocbs=all

at boot time to enable/disable lazy RCU.

To disable it by default at build time when CONFIG_RCU_LAZY=y, the new
CONFIG_RCU_LAZY_DEFAULT_OFF can be used.

Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io>
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
2024-02-14 08:00:57 -08:00
Paul E. McKenney
600716592a doc: Add EARLY flag to early-parsed kernel boot parameters
Kernel boot parameters declared with early_param() are parsed before
embedded parameters are extracted from initrd, and early_param()
parameters are not helpful when embedded in initrd.  Therefore,
mark early_param() kernel boot parameters with "EARLY" in
kernel-parameters.txt.

The following early_param() calls declare kernel boot parameters that
are undocumented:

early_param("atmel.pm_modes", at91_pm_modes_select);
early_param("mem_fclk_21285", early_fclk);
early_param("ecc", early_ecc);
early_param("cachepolicy", early_cachepolicy);
early_param("nodebugmon", early_debug_disable);
early_param("kfence.sample_interval", parse_kfence_early_init);
early_param("additional_cpus", setup_additional_cpus);
early_param("stram_pool", atari_stram_setup);
early_param("disable_octeon_edac", disable_octeon_edac);
early_param("rd_start", rd_start_early);
early_param("rd_size", rd_size_early);
early_param("coherentio", setcoherentio);
early_param("nocoherentio", setnocoherentio);
early_param("fadump", early_fadump_param);
early_param("fadump_reserve_mem", early_fadump_reserve_mem);
early_param("no_stf_barrier", handle_no_stf_barrier);
early_param("no_rfi_flush", handle_no_rfi_flush);
early_param("smt-enabled", early_smt_enabled);
early_param("ppc_pci_reset_phbs", pci_reset_phbs_setup);
early_param("ps3fb", early_parse_ps3fb);
early_param("ps3flash", early_parse_ps3flash);
early_param("novx", disable_vector_extension);
early_param("nobp", nobp_setup_early);
early_param("nospec", nospec_setup_early);
early_param("possible_cpus", _setup_possible_cpus);
early_param("stp", early_parse_stp);
early_param("nopfault", nopfault);
early_param("nmi_mode", nmi_mode_setup);
early_param("sh_mv", early_parse_mv);
early_param("pmb", early_pmb);
early_param("hvirq", early_hvirq_major);
early_param("cfi", cfi_parse_cmdline);
early_param("disableapic", setup_disableapic);
early_param("noapictimer", parse_disable_apic_timer);
early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
early_param("uv_memblksize", parse_mem_block_size);
early_param("retbleed", retbleed_parse_cmdline);
early_param("no-kvmclock-vsyscall", parse_no_kvmclock_vsyscall);
early_param("update_mptable", update_mptable_setup);
early_param("alloc_mptable", parse_alloc_mptable_opt);
early_param("possible_cpus", _setup_possible_cpus);
early_param("lsmsi", early_parse_ls_scfg_msi);
early_param("nokgdbroundup", opt_nokgdbroundup);
early_param("kgdbcon", opt_kgdb_con);
early_param("kasan", early_kasan_flag);
early_param("kasan.mode", early_kasan_mode);
early_param("kasan.vmalloc", early_kasan_flag_vmalloc);
early_param("kasan.page_alloc.sample", early_kasan_flag_page_alloc_sample);
early_param("kasan.page_alloc.sample.order", early_kasan_flag_page_alloc_sample_order);
early_param("kasan.fault", early_kasan_fault);
early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
early_param("kasan.stack_ring_size", early_kasan_flag_stack_ring_size);
early_param("accept_memory", accept_memory_parse);
early_param("page_table_check", early_page_table_check_param);
sh_early_platform_init("earlytimer", &sh_cmt_device_driver);
early_param_on_off("gbpages", "nogbpages", direct_gbpages, CONFIG_X86_DIRECT_GBPAGES);

These are not necessarily bugs, given that some kernel boot parameters
are intended for deep debugging rather than general use.

This work does not cover all of the kernel boot parameters declared using
cmdline_find_option() and cmdline_find_option_bool().  If these are in
fact guaranteed to be early (which appears to be the case), they can be
added in a later version of this patch.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Petr Malat <oss@malat.biz>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: <linux-doc@vger.kernel.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
2024-02-14 07:53:50 -08:00
Ingo Molnar
4589f199eb Merge branch 'x86/bugs' into x86/core, to pick up pending changes before dependent patches
Merge in pending alternatives patching infrastructure changes, before
applying more patches.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-02-14 10:49:37 +01:00
Meng Li
4c7dbd8521 Documentation: PM: amd-pstate: Fix section title underline
Title under line too short

Signed-off-by: Meng Li <li.meng@amd.com>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-02-12 14:40:32 +01:00
Bartosz Golaszewski
104e00bbc7 Merge tag 'v6.8-rc4' into gpio/for-next
Linux 6.8-rc4

Pulling this for a bugfix upstream with which the gpio/for-next branch
conflicts.
2024-02-12 10:12:41 +01:00
Thorsten Blum
f9197538d7 Documentation: admin-guide: tainted-kernels.rst: Add missing article and comma
- Add missing article "the"
- s/above example/example above/
- Add missing comma after introductory clause to improve readability

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240205132409.1957-1-thorsten.blum@toblux.com
2024-02-05 10:25:58 -07:00
Guilherme G. Piccoli
3e3ede49ce docs: Document possible_cpus parameter
The number of possible CPUs is set be kernel in early boot time through
some discovery mechanisms, like ACPI in x86. We have a parameter both
in x86 and S390 to override that - there are some cases of BIOSes exposing
more possible CPUs than the available ones, so this parameter is a good
testing mechanism, but for some reason wasn't mentioned so far in the
kernel parameters guide - let's fix that.

Cc: Changwoo Min <changwoo@igalia.com>
Signed-off-by: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240203152208.1461293-1-gpiccoli@igalia.com
2024-02-05 10:21:08 -07:00
Dorcas Anono Litunya
e76681afdc documentation: media: vivid: Modify typo in documentation
Correct the default value of node_type vivid parameter to 0xe1d3d.

Signed-off-by: Dorcas Anono Litunya <anonolitunya@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
2024-02-05 12:57:46 +01:00
Borislav Petkov (AMD)
2995674833 x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
It was meant well at the time but nothing's using it so get rid of it.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240202163510.GDZb0Zvj8qOndvFOiZ@fat_crate.local
2024-02-03 11:38:17 +01:00
Meng Li
dfddf34a3f Documentation: introduce amd-pstate preferrd core mode kernel command line options
amd-pstate driver support enable/disable preferred core.
Default enabled on platforms supporting amd-pstate preferred core.
Disable amd-pstate preferred core with
"amd_prefcore=disable" added to the kernel command line.

Signed-off-by: Meng Li <li.meng@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-01-31 14:54:50 +01:00
Meng Li
3a004e1fee Documentation: amd-pstate: introduce amd-pstate preferred core
Introduce amd-pstate preferred core.

check preferred core state set by the kernel parameter:
$ cat /sys/devices/system/cpu/amd-pstate/prefcore

Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Meng Li <li.meng@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-01-31 14:54:50 +01:00
Xin Li
3810da1271 x86/fred: Add a fred= cmdline param
Let command line option "fred" accept multiple options to make it
easier to tweak its behavior.

Currently, two options 'on' and 'off' are allowed, and the default
behavior is to disable FRED. To enable FRED, append "fred=on" to the
kernel command line.

  [ bp: Use cpu_feature_enabled(), touch ups. ]

Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-9-xin3.li@intel.com
2024-01-30 18:19:20 +01:00
Mark Pearson
0959afbafa platform/x86: Support for mode FN key
New Thinkpads have added a 'Mode' Function key that on Windows allows
you to choose the active profile (low-power, balanced, performance)

Added suppoort for this hotkey (F8), and have it cycle through the
options available.

Tested on X1 Carbon G12.

Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240120232949.317337-1-mpearson-lenovo@squebb.ca
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2024-01-24 12:40:55 +02:00
Lukas Bulwahn
d546978e0c docs: admin-guide: remove obsolete advice related to SLAB allocator
Commit 1db9d06aaa55 ("mm/slab: remove CONFIG_SLAB from all Kconfig and
Makefile") removes the config SLAB and makes the SLUB allocator the only
default allocator in the kernel. Hence, the advice on reducing OS jitter
due to kworker kernel threads to build with CONFIG_SLUB instead of
CONFIG_SLAB is obsolete.

Remove the obsolete advice to build with SLUB instead of SLAB.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20231130095515.21586-1-lukas.bulwahn@gmail.com
2024-01-23 14:52:37 -07:00
Vegard Nossum
ea7dcd8a48 doc: admin-guide/kernel-parameters: remove useless comment
This comment about DRM drivers has been there since the first git
commit. It simply doesn't belong in kernel-parameters; remove it.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240111085220.3693059-1-vegard.nossum@oracle.com
2024-01-23 14:46:52 -07:00
Xinyu Li
8d4c171f45 docs: cgroup-v1: add missing code-block tags
Hugetlb.rst lacks two code-block tags, causing a formatting issue.

Signed-off-by: Xinyu Li <lixinyu20s@ict.ac.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
2024-01-23 10:49:24 -10:00
Borislav Petkov (AMD)
49527ca264 Documentation/kernel-parameters: Add spec_rstack_overflow to mitigations=off
mitigations=off disables the SRSO mitigation too. Add it to the list.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240118163600.17857-1-bp@alien8.de
2024-01-23 19:52:53 +01:00
Kent Gibson
c055f7ed97 Documentation: gpio: move gpio-mockup into obsolete section
The gpio-mockup has been obsoleted by the gpio-sim, so relocate its
documentation into the obsolete section of the admin-guide book.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22 10:49:07 +01:00
Kent Gibson
c3d336cae7 Documentation: gpio: document gpio-mockup as obsoleted by gpio-sim
Update the gpio-mockup documentation to note that is has been
obsoleted by the gpio-sim.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22 10:49:07 +01:00
Kent Gibson
f1ccbe9aae Documentation: gpio: capitalize GPIO in index title
Capitalise the title of the GPIO documentation page to match other
subsystems.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22 10:49:07 +01:00
Kent Gibson
16b2bb7fe5 Documentation: gpio: add chardev v1 userspace API documentation
Add documentation for v1 of the GPIO character device userspace API
to the obsolete section of both the admin-guide and userspace-api
books.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22 10:49:07 +01:00
Kent Gibson
5054626a9b Documentation: gpio: move sysfs into an obsolete section
The GPIO sysfs API is long obsolete, so highlight this even further
by moving it into an obsolete APIs section in both the admin-guide
and userspace-api books.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22 10:49:06 +01:00
Kent Gibson
32a0a0da53 Documentation: gpio: add chardev userspace API documentation
Add documentation for the GPIO character device userspace API.

Added to the userspace-api book, but also provide a link from the
admin-guide book, as historically the GPIO documentation has been
there.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2024-01-22 10:47:14 +01:00
Xiongwei Song
671776b32b mm/slub: unify all sl[au]b parameters with "slab_$param"
Since the SLAB allocator has been removed, so we can clean up the
sl[au]b_$params. With only one slab allocator left, it's better to use the
generic "slab" term instead of "slub" which is an implementation detail,
which is pointed out by Vlastimil Babka. For more information please see
[1]. Hence, we are going to use "slab_$param" as the primary prefix.

This patch is changing the following slab parameters
- slub_max_order
- slub_min_order
- slub_min_objects
- slub_debug
to
- slab_max_order
- slab_min_order
- slab_min_objects
- slab_debug
as the primary slab parameters for all references of them in docs and
comments. But this patch won't change variables and functions inside
slub as we will have wider slub/slab change.

Meanwhile, "slub_$params" can also be passed by command line, which is
to keep backward compatibility. Also mark all "slub_$params" as legacy.

Remove the separate descriptions for slub_[no]merge, append legacy tip
for them at the end of descriptions of slab_[no]merge.

[1] https://lore.kernel.org/linux-mm/7512b350-4317-21a0-fab3-4101bc4d8f7a@suse.cz/

Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-01-22 10:31:08 +01:00
Xiongwei Song
f1868165d2 Documentation: kernel-parameters: remove noaliencache
Since slab allocator has already been removed. There is no users of
the noaliencache parameter, so let's remove it.

Suggested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-01-22 10:31:08 +01:00
Linus Torvalds
7a39682022 Merge tag 'v6.8-rc-part2-smb-client' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client updates from Steve French:
 "Various smb client fixes, including multichannel and for SMB3.1.1
  POSIX extensions:

   - debugging improvement (display start time for stats)

   - two reparse point handling fixes

   - various multichannel improvements and fixes

   - SMB3.1.1 POSIX extensions open/create parsing fix

   - retry (reconnect) improvement including new retrans mount parm, and
     handling of two additional return codes that need to be retried on

   - two minor cleanup patches and another to remove duplicate query
     info code

   - two documentation cleanup, and one reviewer email correction"

* tag 'v6.8-rc-part2-smb-client' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update iface_last_update on each query-and-update
  cifs: handle servers that still advertise multichannel after disabling
  cifs: new mount option called retrans
  cifs: reschedule periodic query for server interfaces
  smb: client: don't clobber ->i_rdev from cached reparse points
  smb: client: get rid of smb311_posix_query_path_info()
  smb: client: parse owner/group when creating reparse points
  smb: client: fix parsing of SMB3.1.1 POSIX create context
  cifs: update known bugs mentioned in kernel docs for cifs
  cifs: new nt status codes from MS-SMB2
  cifs: pick channel for tcon and tdis
  cifs: open_cached_dir should not rely on primary channel
  smb3: minor documentation updates
  Update MAINTAINERS email address
  cifs: minor comment cleanup
  smb3: show beginning time for per share stats
  cifs: remove redundant variable tcon_exist
2024-01-20 16:48:07 -08:00