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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 /arch/x86/include/asm/stacktrace.h | |
| parent | 61c1917f47f73c968e92d04d15370b1dc3ec4592 (diff) | |
| download | linux-0-day-06d65bda75341485d32f33da474b0664819ad497.tar.gz linux-0-day-06d65bda75341485d32f33da474b0664819ad497.tar.xz | |
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 'arch/x86/include/asm/stacktrace.h')
| -rw-r--r-- | arch/x86/include/asm/stacktrace.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h index 6c75151a3cca8..35e89122a42f5 100644 --- a/arch/x86/include/asm/stacktrace.h +++ b/arch/x86/include/asm/stacktrace.h @@ -22,6 +22,12 @@ print_context_stack(struct thread_info *tinfo, const struct stacktrace_ops *ops, void *data, unsigned long *end, int *graph); +extern unsigned long +print_context_stack_bp(struct thread_info *tinfo, + unsigned long *stack, unsigned long bp, + const struct stacktrace_ops *ops, void *data, + unsigned long *end, int *graph); + /* Generic stack tracer with callbacks */ struct stacktrace_ops { |