From: Beau Belgrave <beaub@linux.microsoft.com>
To: rostedt@goodmis.org, mhiramat@kernel.org
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
torvalds@linux-foundation.org, ast@kernel.org
Subject: [PATCH v3 0/4] tracing/user_events: Use non-RCU context for enabler writes
Date: Fri, 19 May 2023 16:07:37 -0700 [thread overview]
Message-ID: <20230519230741.669-1-beaub@linux.microsoft.com> (raw)
Currently when events are enabled/disabled a top level mm enumeration is
done in a non-RCU context, however, the enablers are still in a
RCU-context. Each enabler is updated via user_event_enabler_write() which
uses pin_user_pages_remote(). This function can reschedule and should not
be used from a RCU-context, which this series addresses.
There was also feedback given that some of the code was confusing and
needed further comments and field renames, especially for links. I think
having this feedback will help others contribute to this code easier, so
I am grouping this into a single series to address this together.
NOTE: Series is based on the for-next branch of the following tree:
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
Change history
V3:
Use Linus's patches to more completely solve this issue.
Added comments and renamed fields as suggested by Linus to ensure easier
reasoning over the code for everyone.
V2:
Remove break statement that prevents more than 1 enabler in MM for same
event (rare, but possible).
Beau Belgrave (2):
tracing/user_events: Rename link fields for clarity
tracing/user_events: Document user_event_mm one-shot list usage
Linus Torvalds (2):
tracing/user_events: Split up mm alloc and attach
tracing/user_events: Remove RCU lock while pinning pages
include/linux/user_events.h | 3 +-
kernel/trace/trace_events_user.c | 97 +++++++++++++++++++++-----------
2 files changed, 67 insertions(+), 33 deletions(-)
base-commit: 3862f86c1529fa0016de6344eb974877b4cd3838
--
2.25.1
next reply other threads:[~2023-05-19 23:08 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-19 23:07 Beau Belgrave [this message]
2023-05-19 23:07 ` [PATCH v3 1/4] tracing/user_events: Split up mm alloc and attach Beau Belgrave
2023-05-19 23:07 ` [PATCH v3 2/4] tracing/user_events: Remove RCU lock while pinning pages Beau Belgrave
2023-05-19 23:07 ` [PATCH v3 3/4] tracing/user_events: Rename link fields for clarity Beau Belgrave
2023-05-19 23:07 ` [PATCH v3 4/4] tracing/user_events: Document user_event_mm one-shot list usage Beau Belgrave
2023-05-20 2:15 ` [PATCH v3 0/4] tracing/user_events: Use non-RCU context for enabler writes Linus Torvalds
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