Commit 043da846 authored by Leo Yan's avatar Leo Yan Committed by Arnaldo Carvalho de Melo
Browse files

perf docs: Refine the description for the buffer size 



Current description for the AUX trace buffer size is misleading. When a
user specifies the option '-m,512M', it represents a size value in bytes
(512MiB) but not 512M pages (512M x 4KiB regard to a page of 4KiB).

Make the document clear that the normal buffer and the AUX tracing
buffer share the same semantics. Syncs the documents for consistent
text.

Reviewed-by: default avatarJames Clark <james.clark@linaro.org>
Signed-off-by: default avatarLeo Yan <leo.yan@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240812093459.2575278-1-leo.yan@arm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e6b56ae7

tools/perf/Documentation/perf-kvm.txt

+3 −3
Original line number Diff line number Diff line
@@ -116,8 +116,8 @@ STAT LIVE OPTIONS 
-m::

--mmap-pages=::

        Number of mmap data pages (must be a power of two) or size

    specification with appended unit character - B/K/M/G. The

    size is rounded up to have nearest pages power of two value.

        specification in bytes with appended unit character - B/K/M/G.

        The size is rounded up to the nearest power-of-two page value.



-a::

--all-cpus::

tools/perf/Documentation/perf-record.txt

+5 −4
Original line number Diff line number Diff line
@@ -273,10 +273,11 @@ OPTIONS 
-m::

--mmap-pages=::

	Number of mmap data pages (must be a power of two) or size

	specification with appended unit character - B/K/M/G. The

	size is rounded up to have nearest pages power of two value.

	Also, by adding a comma, the number of mmap pages for AUX

	area tracing can be specified.

	specification in bytes with appended unit character - B/K/M/G.

	The size is rounded up to the nearest power-of-two page value.

	By adding a comma, an additional parameter with the same

	semantics used for the normal mmap areas can be specified for

	AUX tracing area.



-g::

	Enables call-graph (stack chain/backtrace) recording for both

tools/perf/Documentation/perf-top.txt

+2 −2
Original line number Diff line number Diff line
@@ -83,8 +83,8 @@ Default is to monitor all CPUS. 
-m <pages>::

--mmap-pages=<pages>::

	Number of mmap data pages (must be a power of two) or size

	specification with appended unit character - B/K/M/G. The

	size is rounded up to have nearest pages power of two value.

	specification in bytes with appended unit character - B/K/M/G.

	The size is rounded up to the nearest power-of-two page value.



-p <pid>::

--pid=<pid>::

tools/perf/Documentation/perf-trace.txt

+2 −2
Original line number Diff line number Diff line
@@ -106,8 +106,8 @@ filter out the startup phase of the program, which is often very different. 
-m::

--mmap-pages=::

	Number of mmap data pages (must be a power of two) or size

	specification with appended unit character - B/K/M/G. The

	size is rounded up to have nearest pages power of two value.

	specification in bytes with appended unit character - B/K/M/G.

	The size is rounded up to the nearest power-of-two page value.



-C::

--cpu::