2012-06-06 16:03:21

by Arun Sharma

[permalink] [raw]
Subject: [tip:perf/core] perf: Limit callchains to 127

Commit-ID: 0b0d9cf6ec7bab91977da2d71c09157f110f7c2e
Gitweb: http://git.kernel.org/tip/0b0d9cf6ec7bab91977da2d71c09157f110f7c2e
Author: Arun Sharma <[email protected]>
AuthorDate: Fri, 20 Apr 2012 15:41:34 -0700
Committer: Ingo Molnar <[email protected]>
CommitDate: Wed, 6 Jun 2012 17:08:00 +0200

perf: Limit callchains to 127

Stack depth of 255 seems excessive, given that copy_from_user_nmi()
could be slow.

Signed-off-by: Arun Sharma <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: [email protected]
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
include/linux/perf_event.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 1817d40..45db49f 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -555,7 +555,7 @@ enum perf_event_type {
PERF_RECORD_MAX, /* non-ABI */
};

-#define PERF_MAX_STACK_DEPTH 255
+#define PERF_MAX_STACK_DEPTH 127

enum perf_callchain_context {
PERF_CONTEXT_HV = (__u64)-32,