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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-12-17 05:40:34 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-12-17 10:42:52 +0100 |
| commit | 06d65bda75341485d32f33da474b0664819ad497 (patch) | |
| tree | 3b5edc58b9c5a6a9b5cff4b5886f54929b12863a /kernel/perf_event.c | |
| parent | perf events, x86/stacktrace: Make stack walking optional (diff) | |
| download | linux-06d65bda75341485d32f33da474b0664819ad497.tar.xz linux-06d65bda75341485d32f33da474b0664819ad497.zip | |
perf events, x86/stacktrace: Fix performance/softlockup by providing a special frame pointer-only stack walker
It's just wasteful for stacktrace users like perf to walk
through every entries on the stack whereas these only accept
reliable ones, ie: that the frame pointer validates.
Since perf requires pure reliable stacktraces, it needs a stack
walker based on frame pointers-only to optimize the stacktrace
processing.
This might solve some near-lockup scenarios that can be triggered
by call-graph tracing timer events.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1261024834-5336-2-git-send-regression-fweisbec@gmail.com>
[ v2: fix for modular builds and small detail tidyup ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_event.c')
0 files changed, 0 insertions, 0 deletions