Messages in this thread Patch in this message | | | Date | Wed, 25 Jul 2012 12:29:10 -0700 | From | tip-bot for Jovi Zhang <> | Subject | [tip:perf/core] perf tools: Make the breakpoint events sample period default to 1 |
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Commit-ID: 4a841d650ea435c69e60675537f158a620697290 Gitweb: http://git.kernel.org/tip/4a841d650ea435c69e60675537f158a620697290 Author: Jovi Zhang <bookjovi@gmail.com> AuthorDate: Sun, 15 Jul 2012 03:03:10 +0800 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitDate: Wed, 25 Jul 2012 11:37:46 -0300
perf tools: Make the breakpoint events sample period default to 1
There have one problem about hw_breakpoint perf event, as watched, the events reported to userspace is not correctly, sometime one trigger bp_event report several events, sometime bp_event cannot go through to user.
The root cause is attr->freq is 1 passed to kernel defaultly in bp events, this make kernel calculate event period not as expect, make sample period to 1 will change attr->freq to 0, to fix this problem.
This patch is similar with commit f92128 about tracepoint events: perf: Make the trace events sample period default to 1
Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/CACV3sbLF8taiCq_VYW-sgRJyupeMzg58C7ZXfMe3xZUiH_Mx6w@mail.gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/parse-events.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index a729945..74a5af4 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -490,6 +490,7 @@ int parse_events_add_breakpoint(struct list_head **list, int *idx, attr.bp_len = HW_BREAKPOINT_LEN_4; attr.type = PERF_TYPE_BREAKPOINT; + attr.sample_period = 1; return add_event(list, idx, &attr, NULL); }
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