tracing/filters: Document cpumask filtering

Cpumask, scalar and CPU fields can now be filtered by a user-provided
cpumask, document the syntax.

Link: https://lkml.kernel.org/r/20230707172155.70873-10-vschneid@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Leonardo Bras <leobras@redhat.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Valentin Schneider 2023-07-07 18:21:55 +01:00 committed by Steven Rostedt (Google)
parent 38c6f68083
commit fa828efb9c
1 changed files with 14 additions and 0 deletions

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@ -219,6 +219,20 @@ the function "security_prepare_creds" and less than the end of that function.
The ".function" postfix can only be attached to values of size long, and can only
be compared with "==" or "!=".
Cpumask fields or scalar fields that encode a CPU number can be filtered using
a user-provided cpumask in cpulist format. The format is as follows::
CPUS{$cpulist}
Operators available to cpumask filtering are:
& (intersection), ==, !=
For example, this will filter events that have their .target_cpu field present
in the given cpumask::
target_cpu & CPUS{17-42}
5.2 Setting filters
-------------------