kernel test robot reported htmldocs warning:
Documentation/admin-guide/pm/amd-pstate.rst:343: WARNING: duplicate label admin-guide/pm/amd-pstate:user space interface in ``sysfs``, other instance in Documentation/admin-guide/pm/amd-pstate.rst
The documentation contains two sections with the same "User Space Interface
in ``sysfs``" title. The first one deals with per-policy sysfs and the
second one is about general attributes (currently only global attributes
are documented).
Disambiguate title text of both sections to fix the warning.
Link: https://lore.kernel.org/linux-doc/202302151041.0SWs1RHK-lkp@intel.com/
Fixes: b9e6a2d47b2565 ("Documentation: amd-pstate: introduce new global sysfs attributes")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The following warning:
Documentation/admin-guide/hw-vuln/cross-thread-rsb.rst:92: ERROR: Unexpected indentation.
was introduced by commit 493a2c2d23ca. Fix it by placing everything in
the same paragraph and also use a monospace font.
Fixes: 493a2c2d23ca ("Documentation/hw-vuln: Add documentation for Cross-Thread Return Predictions")
Reported-by: Stephen Rothwell <sfr@canb@auug.org.au>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
predictions bug. When running in SMT mode and one of the sibling threads
transitions out of C0 state, the other thread gets access to twice as many
entries in the RSB, but unfortunately the predictions of the now-halted
logical processor are not purged. Therefore, the executing processor
could speculatively execute from locations that the now-halted processor
had trained the RSB on.
The Spectre v2 mitigations cover the Linux kernel, as it fills the RSB
when context switching to the idle thread. However, KVM allows a VMM to
prevent exiting guest mode when transitioning out of C0 using the
KVM_CAP_X86_DISABLE_EXITS capability can be used by a VMM to change this
behavior. To mitigate the cross-thread return address predictions bug,
a VMM must not be allowed to override the default behavior to intercept
C0 transitions.
These patches introduce a KVM module parameter that, if set, will prevent
the user from disabling the HLT, MWAIT and CSTATE exits.
-----BEGIN PGP SIGNATURE-----
iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmPrvAAUHHBib256aW5p
QHJlZGhhdC5jb20ACgkQv/vSX3jHroMQAgf8CirL+yrngzQ+39UTFQgXj3IS1UyR
o2mF39w3bVlQhLNf5MBHF965FUeOV/8A16x73hJGjhiiuisphtQWS/6xKR6uYbq7
0Qi821skqN6XpRsWTWqFHMsdY+n0skr8QeXG4k/GJu7Ghb3tqs4eTGgnf2WBfI8/
K1UgTmjd9+ikM5gKZoVLpcqZnti0gx3lM+cvZGdfrIUaXB+i+hNd2NfRTiGsTOiK
fX7vZtLvOeje2TPoKLhzekTbh8kTU07HRWID9aVXT8bLy6Zd6tg2CHlv11noKpwv
DFVV+RsJ1SiAQYSwT+4IvWfIG4oq4onBQ972g2a27pP2cxF+38GXzt4NQw==
=xscg
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Certain AMD processors are vulnerable to a cross-thread return address
predictions bug. When running in SMT mode and one of the sibling
threads transitions out of C0 state, the other thread gets access to
twice as many entries in the RSB, but unfortunately the predictions of
the now-halted logical processor are not purged. Therefore, the
executing processor could speculatively execute from locations that
the now-halted processor had trained the RSB on.
The Spectre v2 mitigations cover the Linux kernel, as it fills the RSB
when context switching to the idle thread. However, KVM allows a VMM
to prevent exiting guest mode when transitioning out of C0 using the
KVM_CAP_X86_DISABLE_EXITS capability can be used by a VMM to change
this behavior. To mitigate the cross-thread return address predictions
bug, a VMM must not be allowed to override the default behavior to
intercept C0 transitions.
These patches introduce a KVM module parameter that, if set, will
prevent the user from disabling the HLT, MWAIT and CSTATE exits"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
Documentation/hw-vuln: Add documentation for Cross-Thread Return Predictions
KVM: x86: Mitigate the cross-thread return address predictions bug
x86/speculation: Identify processors vulnerable to SMT RSB predictions
Patch series "mm/damon: deprecate DAMON debugfs interface".
DAMON debugfs interface has announced to be deprecated after >v5.15 LTS
kernel is released. And v6.1.y has been announced to be an LTS[1].
Though the announcement was there for a while, some people might not have
noticed that so far. Also, some users could depend on it and have
problems at movng to the alternative (DAMON sysfs interface).
For such cases, keep the code and documents with warning messages and
contacts to ask helps for the deprecation.
[1] https://git.kernel.org/pub/scm/docs/kernel/website.git/commit/?id=332e9121320bc7461b2d3a79665caf153e51732c
This patch (of 3):
DAMON debugfs interface has announced to be deprecated after >v5.15 LTS
kernel is released. And, v6.1.y has announced to be an LTS[1].
Though the announcement was there for a while, some people might not
noticed that so far. Also, some users could depend on it and have
problems at movng to the alternative (DAMON sysfs interface).
For such cases, note DAMON debugfs interface as deprecated, and contacts
to ask helps on the document.
[1] https://git.kernel.org/pub/scm/docs/kernel/website.git/commit/?id=332e9121320bc7461b2d3a79665caf153e51732c
Link: https://lkml.kernel.org/r/20230209192009.7885-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230209192009.7885-2-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>
Texts in numbered lists are rendered as continous paragraph when there
should have been breaks between first line text in the beginning of list
item and the description. Fix this by adding appropriate line breaks and
indent the rest of lines to match the first line of numbered list item.
Fixes: d6d71ee4a14ae6 ("PM: Introduce Intel PowerClamp Driver")
Fixes: 6bbe6f5732faea ("docs: thermal: convert to ReST")
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
kernel test robot reported htmldocs warning:
Documentation/admin-guide/thermal/intel_powerclamp.rst:328: WARNING: Inline emphasis start-string without end-string.
The mistaken asterisk in /proc/irq/*/smp_affinity is rendered as hyperlink
as the result.
Escape the asterisk to fix above warning.
Link: https://lore.kernel.org/linux-doc/202302122247.N4S791c4-lkp@intel.com/
Fixes: ebf51971021881 ("thermal: intel: powerclamp: Add two module parameters")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a new ARM64_HAS_NESTED_VIRT feature to indicate that the
CPU has the ARMv8.3 nested virtualization capability, together
with the 'kvm-arm.mode=nested' command line option.
This will be used to support nested virtualization in KVM.
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[maz: moved the command-line option to kvm-arm.mode]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Add new kernel parameter cgroup.memory=nobpf to allow user disable bpf
memory accounting. This is a preparation for the followup patch.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Link: https://lore.kernel.org/r/20230210154734.4416-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add the admin guide for the Cross-Thread Return Predictions vulnerability.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <60f9c0b4396956ce70499ae180cb548720b25c7e.1675956146.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
xfs will not allow combining other panic masks with
XFS_PTAG_VERIFIER_ERROR.
# sysctl fs.xfs.panic_mask=511
sysctl: setting key "fs.xfs.panic_mask": Invalid argument
fs.xfs.panic_mask = 511
Update to the maximum value that can be set to allow the full range of
masks. Do this using a mask of possible values to prevent this happening
again as suggested by Darrick.
Fixes: d519da41e2b7 ("xfs: Introduce XFS_PTAG_VERIFIER_ERROR panic mask")
Signed-off-by: Donald Douwsma <ddouwsma@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
If RPS is enabled, this allows configuring a default rps
mask, which is effective since receive queue creation time.
A default RPS mask allows the system admin to ensure proper
isolation, avoiding races at network namespace or device
creation time.
The default RPS mask is initially empty, and can be
modified via a newly added sysctl entry.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In some use cases, it is desirable to only inject idle on certain set
of CPUs. For example on Alder Lake systems, it is possible that we force
idle only on P-Cores for thermal reasons. Also the idle percent can be
more than 50% if we only choose partial set of CPUs in the system.
Introduce 2 new module parameters for this purpose. They can be only
changed when the cooling device is inactive.
cpumask (Read/Write): A bit mask of CPUs to inject idle. The format of
this bitmask is same as used in other subsystems like in
/proc/irq/*/smp_affinity. The mask is comma separated 32 bit groups.
Each CPU is one bit. For example for 256 CPU system the full mask is:
ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff,ffffffff
The rightmost mask is for CPU 0-32.
max_idle (Read/Write): Maximum injected idle time to the total CPU time
ratio in percent range from 1 to 100. Even if the cooling device max_state
is always 100 (100%), this parameter allows to add a max idle percent
limit. The default is 50, to match the current implementation of powerclamp
driver. Also doesn't allow value more than 75, if the cpumask includes
every CPU present in the system.
Also when the cpumask doesn't include every CPU, there is no use of
compensation using package C-state idle counters. Hence don't start
package C-state polling thread even for a single package or a single die
system in this case.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Create a folder "thermal" under Documentation/admin-guide and move
intel_powerclamp documentation to this folder.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-----BEGIN PGP SIGNATURE-----
iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmPgG/geHHRvcnZhbGRz
QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGidAH/j0pUbmniNM3aft8
5O1XxltlOZgqxju8OQhkiuX9VnQuuSeTNhAuj6jfcQOLpXDvlKsVfrpBxEfXalML
yead9QAy/OT3hNGQxifMQzGbsmaWH1kgxxnv2lKo2eNP5KYZ+rec+IgtQhgX9quN
q/N/ymd2/ju9AEOVRYwG1PD1EiIwTd3xPfBZl4Z35J+Ym+6NRrlXmN6J9LwslXmJ
/P4cwgdf9/TuYAB96EshRHsZ4Tk/Gxkn15uyhLaWBmrZ/LAF5JGbClEfFlCWgjwv
F5SGv3F+O6HSv49W9a24XtenE+3tw78AbCdqKZyzbb2whhv1eY99vKSbGnCahc/y
O0VBP/g=
=YoPk
-----END PGP SIGNATURE-----
Merge tag 'v6.2-rc7' into media_tree
Linux 6.2-rc7
* tag 'v6.2-rc7': (1549 commits)
Linux 6.2-rc7
fbcon: Check font dimension limits
efi: fix potential NULL deref in efi_mem_reserve_persistent
kernel/irq/irqdomain.c: fix memory leak with using debugfs_lookup()
HV: hv_balloon: fix memory leak with using debugfs_lookup()
mtk_sgmii: enable PCS polling to allow SFP work
net: mediatek: sgmii: fix duplex configuration
net: mediatek: sgmii: ensure the SGMII PHY is powered down on configuration
MAINTAINERS: update SCTP maintainers
MAINTAINERS: ipv6: retire Hideaki Yoshifuji
mailmap: add John Crispin's entry
MAINTAINERS: bonding: move Veaceslav Falico to CREDITS
net: openvswitch: fix flow memory leak in ovs_flow_cmd_new
net: ethernet: mtk_eth_soc: disable hardware DSA untagging for second MAC
virtio-net: Keep stop() to follow mirror sequence of open()
efi: Accept version 2 of memory attributes table
ceph: blocklist the kclient when receiving corrupted snap trace
ceph: move mount state enum to super.h
selftests: net: udpgso_bench_tx: Cater for pending datagrams zerocopy benchmarking
selftests: net: udpgso_bench: Fix racing bug between the rx/tx programs
...
Add to ftrace_boot_snapshot, "=<instance>" name, where the instance will
get a snapshot buffer, and will take a snapshot at the end of boot (which
will save the boot traces).
Link: https://lkml.kernel.org/r/20230207173026.792774721@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add the format of:
trace_instance=foo,sched:sched_switch,irq_handler_entry,initcall
That will create the "foo" instance and enable the sched_switch event
(here were the "sched" system is explicitly specified), the
irq_handler_entry event, and all events under the system initcall.
Link: https://lkml.kernel.org/r/20230207173026.386114535@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add kernel command line to add tracing instances. This only creates
instances at boot but still does not enable any events to them. Later
changes will extend this command line to add enabling of events, filters,
and triggers. As well as possibly redirecting trace_printk()!
Link: https://lkml.kernel.org/r/20230207173026.186210158@goodmis.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Unconditionally enabling TSC watchdog checking of the HPET and PMTMR
clocksources can degrade latency and performance. Therefore, provide
a new "watchdog" option to the tsc= boot parameter that opts into such
checking. Note that tsc=watchdog is overridden by a tsc=nowatchdog
regardless of their relative positions in the list of boot parameters.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Waiman Long <longman@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
The amd-pstate driver supports switching working modes at runtime.
Users can view and change modes by interacting with the "status" sysfs
attribute.
1) check driver mode:
$ cat /sys/devices/system/cpu/amd-pstate/status
2) switch mode:
`# echo "passive" | sudo tee /sys/devices/system/cpu/amd-pstate/status`
or
`# echo "active" | sudo tee /sys/devices/system/cpu/amd-pstate/status`
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
AMD Pstate driver support another firmware based autonomous mode
with "amd_pstate=active" added to the kernel command line.
In autonomous mode SMU firmware decides frequencies at runtime
based on workload utilization, usage in other IPs, infrastructure
limits such as power, thermals and so on.
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The amd-pstate driver has two operation modes supported:
* CPPC Autonomous (active) mode
* CPPC non-autonomous (passive) mode.
active mode and passive mode can be chosen by different kernel parameters.
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The amd-pstate driver supports a feature called energy performance
preference (EPP). Add information to the documentation to explain
how users can interact with the sysfs files for this feature.
1) See all EPP profiles
$ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_available_preferences
default performance balance_performance balance_power power
2) Check current EPP profile
$ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference
performance
3) Set new EPP profile
$ sudo bash -c "echo power > /sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference"
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
kexec allows replacing the current kernel with a different one. This is
usually a source of concerns for sysadmins that want to harden a system.
Linux already provides a way to disable loading new kexec kernel via
kexec_load_disabled, but that control is very coard, it is all or nothing
and does not make distinction between a panic kexec and a normal kexec.
This patch introduces new sysctl parameters, with finer tuning to specify
how many times a kexec kernel can be loaded. The sysadmin can set
different limits for kexec panic and kexec reboot kernels. The value can
be modified at runtime via sysctl, but only with a stricter value.
With these new parameters on place, a system with loadpin and verity
enabled, using the following kernel parameters:
sysctl.kexec_load_limit_reboot=0 sysct.kexec_load_limit_panic=1 can have a
good warranty that if initrd tries to load a panic kernel, a malitious
user will have small chances to replace that kernel with a different one,
even if they can trigger timeouts on the disk where the panic kernel
lives.
Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-3-6a8531a09b9a@chromium.org
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "kexec: Add new parameter to limit the access to kexec", v6.
Add two parameter to specify how many times a kexec kernel can be loaded.
These parameter allow hardening the system.
While we are at it, fix a documentation issue and refactor some code.
This patch (of 3):
kexec_load_disabled affects both ``kexec_load`` and ``kexec_file_load``
syscalls. Make it explicit.
Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-0-6a8531a09b9a@chromium.org
Link: https://lkml.kernel.org/r/20221114-disable-kexec-reset-v6-1-6a8531a09b9a@chromium.org
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Guilherme G. Piccoli <gpiccoli@igalia.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Supports of each DAMOS action and filters are up to DAMON operations set
implementation, but it's not mentioned in detail on the documentation.
Update the information on the usage document.
Link: https://lkml.kernel.org/r/20230110190400.119388-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The kernel assumes that the TSC frequency which is provided by the
hardware / firmware via MSRs or CPUID(0x15) is correct after applying
a few basic consistency checks. This disables the TSC recalibration
against HPET or PM timer.
As a result there is no mechanism to validate that frequency in cases
where a firmware or hardware defect is suspected. And there was case
that some user used atomic clock to measure the TSC frequency and
reported an inaccuracy issue, which was later fixed in firmware.
Add an option 'recalibrate' for 'tsc' kernel parameter to force the
tsc freq recalibration with HPET or PM timer, and warn if the
deviation from previous value is more than about 500 PPM, which
provides a way to verify the data from hardware / firmware.
There is no functional change to existing work flow.
Recently there was a real-world case: "The 40ms/s divergence between
TSC and HPET was observed on hardware that is quite recent" [1], on
that platform the TSC frequence 1896 MHz was got from CPUID(0x15),
and the force-reclibration with HPET/PMTIMER both calibrated out
value of 1975 MHz, which also matched with check from software
'chronyd', indicating it's a problem of BIOS or firmware.
[Thanks tglx for helping improving the commit log]
[ paulmck: Wordsmith Kconfig help text. ]
[1]. https://lore.kernel.org/lkml/20221117230910.GI4001@paulmck-ThinkPad-P17-Gen-1/
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: <x86@kernel.org>
Cc: <linux-doc@vger.kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Document the fact that CONFIG_BOOT_PRINTK_DELAY must be enabled for the
"boot_delay" kernel parameter to work. Also mention that "lpj=" may be
necessary.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20230126225420.1320276-1-helgaas@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add a new section to the admin-guide with information of interest to
application developers and system integrators doing analysis of the
Linux kernel for safety critical applications.
This section will contain documents supporting analysis of kernel
interactions with applications, and key kernel subsystems expectations.
Add a new workload-tracing document to this new section.
Signed-off-by: Shefali Sharma <sshefali021@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230131221105.39216-1-skhan@linuxfoundation.org
[jc: tweaked the sphinx formatting a bit]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
It is enough to use a file name to cross-reference another rst document.
Jon says:
The right things will happen in the HTML output, readers of the
plain-text will know immediately where to go, and we don't have to add
the label clutter.
Drop reference markup and unnecessary labels and use plain file names.
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Link: https://lore.kernel.org/r/20230201094156.991542-4-rppt@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This reverts commit 12a5d3955227b0d7e04fb793ccceeb2a1dd275c5.
Although it is recognized that a finer grained pro-active reclaim is
something we need and want the semantic of this implementation is really
ambiguous.
In a follow up discussion it became clear that there are two essential
usecases here. One is to use memory.reclaim to pro-actively reclaim
memory and expectation is that the requested and reported amount of memory
is uncharged from the memcg. Another usecase focuses on pro-active
demotion when the memory is merely shuffled around to demotion targets
while the overall charged memory stays unchanged.
The current implementation considers demoted pages as reclaimed and that
break both usecases. [1] has tried to address the reporting part but
there are more issues with that summarized in [2] and follow up emails.
Let's revert the nodemask based extension of the memcg pro-active
reclaim for now until we settle with a more robust semantic.
[1] http://lkml.kernel.org/r/http://lkml.kernel.org/r/20221206023406.3182800-1-almasrymina@google.com
[2] http://lkml.kernel.org/r/Y5bsmpCyeryu3Zz1@dhcp22.suse.cz
Link: https://lkml.kernel.org/r/Y5xASNe1x8cusiTx@dhcp22.suse.cz
Fixes: 12a5d3955227b0d ("mm: add nodes= arg to memory.reclaim")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: zefan li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The canonical location for the tracefs filesystem is at /sys/kernel/tracing.
But, from Documentation/trace/ftrace.rst:
Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:
/sys/kernel/debug/tracing
Many parts of Documentation still reference this older debugfs path, so
let's update them to avoid confusion.
Signed-off-by: Ross Zwisler <zwisler@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230125213251.2013791-1-zwisler@google.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
%s/modules/module/
Signed-off-by: Hui Su <suhui_kernel@163.com>
Reviewed-by: Alex Shi <alexsshi@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Link: https://lore.kernel.org/r/Y9Tm1FiKBPKA2Tcx@localhost.localdomain
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
-----BEGIN PGP SIGNATURE-----
iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmPW7E8eHHRvcnZhbGRz
QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGf7MIAI0JnHN9WvtEukSZ
E6j6+cEGWxsvD6q0g3GPolaKOCw7hlv0pWcFJFcUAt0jebspMdxV2oUGJ8RYW7Lg
nCcHvEVswGKLAQtQSWw52qotW6fUfMPsNYYB5l31sm1sKH4Cgss0W7l2HxO/1LvG
TSeNHX53vNAZ8pVnFYEWCSXC9bzrmU/VALF2EV00cdICmfvjlgkELGXoLKJJWzUp
s63fBHYGGURSgwIWOKStoO6HNo0j/F/wcSMx8leY8qDUtVKHj4v24EvSgxUSDBER
ch3LiSQ6qf4sw/z7pqruKFthKOrlNmcc0phjiES0xwwGiNhLv0z3rAhc4OM2cgYh
SDc/Y/c=
=zpaD
-----END PGP SIGNATURE-----
Merge tag 'v6.2-rc6' into sched/core, to pick up fixes
Pick up fixes before merging another batch of cpuidle updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Remove PARIDE core and high level protocols, taking care not to break
low-level drivers (used by pata_parport). Also update documentation.
Signed-off-by: Ondrej Zary <linux@zary.sk>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
The pata_parport is a libata-based replacement of the old PARIDE
subsystem - driver for parallel port IDE devices.
It uses the original paride low-level protocol drivers but does not
need the high-level drivers (pd, pcd, pf, pt, pg). The IDE devices
behind parallel port adapters are handled by the ATA layer.
This will allow paride and its high-level drivers to be removed.
Unfortunately, libata drivers cannot sleep so pata_parport claims
parport before activating the ata host and keeps it claimed (and
protocol connected) until the ata host is removed. This means that
no devices can be chained (neither other pata_parport devices nor
a printer).
paride and pata_parport are mutually exclusive because the compiled
protocol drivers are incompatible.
Tested with:
- Imation SuperDisk LS-120 and HP C4381A (EPAT)
- Freecom Parallel CD (FRPW)
- Toshiba Mobile CD-RW 2793008 w/Freecom Parallel Cable rev.903 (FRIQ)
- Backpack CD-RW 222011 and CD-RW 19350 (BPCK6)
The following bugs in low-level protocol drivers were found and will
be fixed later:
Note: EPP-32 mode is buggy in EPAT - and also in all other protocol
drivers - they don't handle non-multiple-of-4 block transfers
correctly. This causes problems with LS-120 drive.
There is also another bug in EPAT: EPP modes don't work unless a 4-bit
or 8-bit mode is used first (probably some initialization missing?).
Once the device is initialized, EPP works until power cycle.
So after device power on, you have to:
echo "parport0 epat 0" >/sys/bus/pata_parport/new_device
echo pata_parport.0 >/sys/bus/pata_parport/delete_device
echo "parport0 epat 4" >/sys/bus/pata_parport/new_device
(autoprobe will initialize correctly as it tries the slowest modes
first but you'll get the broken EPP-32 mode)
Note: EPP modes are buggy in FRPW, only modes 0 and 1 work.
Signed-off-by: Ondrej Zary <linux@zary.sk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
The AMD Zen4 core supports a new feature called Automatic IBRS.
It is a "set-and-forget" feature that means that, like Intel's Enhanced IBRS,
h/w manages its IBRS mitigation resources automatically across CPL transitions.
The feature is advertised by CPUID_Fn80000021_EAX bit 8 and is enabled by
setting MSR C000_0080 (EFER) bit 21.
Enable Automatic IBRS by default if the CPU feature is present. It typically
provides greater performance over the incumbent generic retpolines mitigation.
Reuse the SPECTRE_V2_EIBRS spectre_v2_mitigation enum. AMD Automatic IBRS and
Intel Enhanced IBRS have similar enablement. Add NO_EIBRS_PBRSB to
cpu_vuln_whitelist, since AMD Automatic IBRS isn't affected by PBRSB-eIBRS.
The kernel command line option spectre_v2=eibrs is used to select AMD Automatic
IBRS, if available.
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Sean Christopherson <seanjc@google.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/r/20230124163319.2277355-8-kim.phillips@amd.com
The tm6000 driver does not use the vb2 framework for streaming
video, instead it uses the old vb1 framework and nobody stepped in to
convert this driver to vb2.
The hardware is very old, so the decision was made to remove it
altogether since we want to get rid of the old vb1 framework.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
The zr364xx driver does not use the vb2 framework for streaming
video, instead it uses the old vb1 framework and nobody stepped in to
convert this driver to vb2.
The hardware is very old, so the decision was made to remove it
altogether since we want to get rid of the old vb1 framework.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
The stkwebcam driver does not use the vb2 framework for streaming
video, instead it implements this in the driver. This is error prone,
and nobody stepped in to convert this driver to that framework.
The hardware is very old, so the decision was made to remove it
altogether.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
