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authorFrederic Weisbecker <fweisbec@gmail.com>2009-12-17 05:40:34 +0100
committerIngo Molnar <mingo@elte.hu>2009-12-17 10:42:52 +0100
commit06d65bda75341485d32f33da474b0664819ad497 (patch)
tree3b5edc58b9c5a6a9b5cff4b5886f54929b12863a /arch/x86/include/asm/stacktrace.h
parent61c1917f47f73c968e92d04d15370b1dc3ec4592 (diff)
downloadblackbird-obmc-linux-06d65bda75341485d32f33da474b0664819ad497.tar.gz
blackbird-obmc-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 'arch/x86/include/asm/stacktrace.h')
-rw-r--r--arch/x86/include/asm/stacktrace.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h
index 6c75151a3cca..35e89122a42f 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 {
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