No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Sandipan Das 2492e5aba2 perf/x86/amd/uncore: Prevent UMC counters from saturating
Unlike L3 and DF counters, UMC counters (PERF_CTRs) set the Overflow bit
(bit 48) and saturate on overflow. A subsequent pmu->read() of the event
reports an incorrect accumulated count as there is no difference between
the previous and the current values of the counter.

To avoid this, inspect the current counter value and proactively reset
the corresponding PERF_CTR register on every pmu->read(). Combined with
the periodic reads initiated by the hrtimer, the counters never get a
chance saturate but the resolution reduces to 47 bits.

Fixes: 25e5684782 ("perf/x86/amd/uncore: Add memory controller support")
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/dee9c8af2c6d66814cf4c6224529c144c620cf2c.1744906694.git.sandipan.das@amd.com
History 2025-04-18 10:35:34 +02:00
arch perf/x86/amd/uncore: Prevent UMC counters from saturating 2025-04-18 10:35:34 +02:00
block treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes reverts the multibuffer hash testing as it is buggy. 2025-04-02 09:14:59 -07:00
Documentation A few more miscellaneous ext4 bug fixes and cleanups including some 2025-04-13 07:15:50 -07:00
drivers pwm: A set of fixes for pwm core and various drivers 2025-04-12 08:11:19 -07:00
fs Changes since last update: 2025-04-13 10:52:04 -07:00
include Merge branch 'perf/urgent' into perf/core, to pick up fixes 2025-04-17 14:20:57 +02:00
init Miscellaneous scheduler fixes/updates: 2025-04-06 10:44:58 -07:00
io_uring io_uring/kbuf: reject zero sized provided buffers 2025-04-07 07:51:23 -06:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel perf/core: Fix event timekeeping merge 2025-04-17 14:21:15 +02:00
lib CRC cleanups for 6.15 2025-04-08 12:09:28 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm Disable SLUB_TINY for build testing 2025-04-06 10:00:04 -07:00
net bpf-fixes 2025-04-12 12:48:10 -07:00
rust Kbuild updates for v6.15 2025-04-05 15:46:50 -07:00
samples treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
scripts Disable SLUB_TINY for build testing 2025-04-06 10:00:04 -07:00
security mseal sysmap: kernel config and header change 2025-04-01 15:17:14 -07:00
sound soundwire fix for 6.15-rc1 2025-04-06 12:04:53 -07:00
tools selftests/bpf: Add 5-byte NOP uprobe trigger benchmark 2025-04-18 09:03:45 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt ARM: 2025-04-08 13:47:55 -07:00
.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: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.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: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00
.mailmap mailmap: add an entry for Nicolas Schier 2025-04-01 15:20:45 -07:00
.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 Including fixes from netfilter. 2025-04-04 09:15:35 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS MAINTAINERS: add more keywords for the GPIO subsystem entry 2025-04-08 10:41:58 +02:00
Makefile Linux 6.15-rc2 2025-04-13 11:54:49 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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.