Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-12-29 17:25:38 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
Linux kernel stable tree
1,323,400 Commits 106 Branches 5,179 Tags 6 GiB
C 97.5%
Assembly 1%
Shell 0.6%
Python 0.3%
Makefile 0.3%
9f3de72a0c
Go to file
Kan Liang 9f3de72a0c perf/x86/intel/ds: Unconditionally drain PEBS DS when changing PEBS_DATA_CFG 
The PEBS kernel warnings can still be observed with the below case.

when the below commands are running in parallel for a while.

  while true;
  do
	perf record --no-buildid -a --intr-regs=AX  \
		    -e cpu/event=0xd0,umask=0x81/pp \
		    -c 10003 -o /dev/null ./triad;
  done &

  while true;
  do
	perf record -e 'cpu/mem-loads,ldlat=3/uP' -W -d -- ./dtlb
  done

The commit b752ea0c28 ("perf/x86/intel/ds: Flush PEBS DS when changing
PEBS_DATA_CFG") intends to flush the entire PEBS buffer before the
hardware is reprogrammed. However, it fails in the above case.

The first perf command utilizes the large PEBS, while the second perf
command only utilizes a single PEBS. When the second perf event is
added, only the n_pebs++. The intel_pmu_pebs_enable() is invoked after
intel_pmu_pebs_add(). So the cpuc->n_pebs == cpuc->n_large_pebs check in
the intel_pmu_drain_large_pebs() fails. The PEBS DS is not flushed.
The new PEBS event should not be taken into account when flushing the
existing PEBS DS.

The check is unnecessary here. Before the hardware is reprogrammed, all
the stale records must be drained unconditionally.

For single PEBS or PEBS-vi-pt, the DS must be empty. The drain_pebs()
can handle the empty case. There is no harm to unconditionally drain the
PEBS DS.

Fixes: b752ea0c28 ("perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20241119135504.1463839-2-kan.liang@linux.intel.com
2024-12-02 12:01:33 +01:00
arch perf/x86/intel/ds: Unconditionally drain PEBS DS when changing PEBS_DATA_CFG 2024-12-02 12:01:33 +01:00
block block-6.13-20242901 2024-11-30 15:47:29 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto Random number generator updates for Linux 6.13-rc1. 2024-11-19 10:43:44 -08:00
Documentation - Move the ->select callback to the correct ops structure in irq-mvebu-sei to 2024-12-01 12:37:58 -08:00
drivers i2c-for-6.13-rc1-part3 2024-12-01 13:38:24 -08:00
fs This pull request contains the following changes for UML: 2024-11-30 10:34:54 -08:00
include i2c-for-6.13-rc1-part3 2024-12-01 13:38:24 -08:00
init - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
io_uring io_uring-6.13-20242901 2024-11-30 15:43:02 -08:00
ipc - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
kernel - Fix a case where posix timers with a thread-group-wide target would miss 2024-12-01 12:41:21 -08:00
lib vsnprintf: Removal of bprintf() 2024-12-01 13:10:51 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
net 9p update for 6.13-rc1 2024-11-30 10:28:14 -08:00
rust block-6.13-20242901 2024-11-30 15:47:29 -08:00
samples TTY / Serial driver updates for 6.13-rc1 2024-11-30 09:03:16 -08:00
scripts Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
security lsm/stable-6.13 PR 20241129 2024-11-30 18:14:56 -08:00
sound sound fixes for 6.13-rc1 2024-11-29 13:01:05 -08:00
tools turbostat version 2024.11.30 2024-11-30 18:30:22 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt VFIO updates for v6.13 2024-11-27 12:57:03 -08:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: enable Clippy's check-private-items 2024-10-07 21:39:57 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
.mailmap media updates for v6.13-rc1 2024-11-20 14:01:15 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS cgroup: Changes for v6.13 2024-11-20 09:54:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS i2c-for-6.13-rc1-part3 2024-12-01 13:38:24 -08:00
Makefile Linux 6.13-rc1 2024-12-01 14:28:56 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.