linux-kernel - [PATCH 0/2] membarrier: allow cpu

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Message-ID: <20250626155257.81256-1-dyudaken@gmail.com>
Date: Thu, 26 Jun 2025 16:52:55 +0100
From: Dylan Yudaken <dyudaken@...il.com>
To: mathieu.desnoyers@...icios.com,
	paulmck@...nel.org
Cc: mingo@...hat.com,
	peterz@...radead.org,
	juri.lelli@...hat.com,
	vincent.guittot@...aro.org,
	dietmar.eggemann@....com,
	rostedt@...dmis.org,
	bsegall@...gle.com,
	mgorman@...e.de,
	vschneid@...hat.com,
	shuah@...nel.org,
	linux-kernel@...r.kernel.org,
	linux-kselftest@...r.kernel.org,
	Dylan Yudaken <dyudaken@...il.com>
Subject: [PATCH 0/2] membarrier: allow cpu_id to be set on more commands

Hi,

I noticed that only the RSEQ membarrier command allows specifying a
specific cpu. I have a (extremely toy) lib I was playing around with [1] and
noticed this and that being able to specify the cpu would be useful to
me.

I'm by no means an expert in this code though - and so could be
totally missing something.

Additionally this seems really difficult to actually test. I added a
self test that just proces "some" interrupts are being sent, but
nothing more than that. I don't know what else can be done there.

Patch 1 is the main change
Patch 2 is the self-test. Which maybe you don't want at all.

[1]: https://github.com/DylanZA/rseqlock/commit/be7bc7214fd5aacec47e26126118f8bbdda0f0ea

Thanks,
Dylan

Dylan Yudaken (2):
  membarrier: allow cpu_id to be set on more commands
  membarrier: self test for cpu specific calls

 kernel/sched/membarrier.c                     |   6 +-
 tools/testing/selftests/membarrier/.gitignore |   1 +
 tools/testing/selftests/membarrier/Makefile   |   3 +-
 .../membarrier/membarrier_test_expedited.c    | 135 ++++++++++++++++++
 .../membarrier/membarrier_test_impl.h         |   5 +
 5 files changed, 148 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/membarrier/membarrier_test_expedited.c

base-commit: ee88bddf7f2f5d1f1da87dd7bedc734048b70e88
-- 
2.49.0