Messages in this thread Patch in this message | | | Date | Thu, 2 Apr 2015 11:36:35 -0700 | From | tip-bot for Kan Liang <> | Subject | [tip:perf/core] perf/x86/intel: Filter branches for PEBS event |
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Commit-ID: 687805e4a60fe83a11556c041840161f8016a367 Gitweb: http://git.kernel.org/tip/687805e4a60fe83a11556c041840161f8016a367 Author: Kan Liang <kan.liang@intel.com> AuthorDate: Fri, 27 Mar 2015 10:38:25 -0400 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Thu, 2 Apr 2015 17:07:42 +0200
perf/x86/intel: Filter branches for PEBS event
For supporting Intel LBR branches filtering, Intel LBR sharing logic mechanism is introduced from commit b36817e88630 ("perf/x86: Add Intel LBR sharing logic"). It modifies __intel_shared_reg_get_constraints() to config lbr_sel, which is finally used to set LBR_SELECT.
However, the intel_shared_regs_constraints() function is called after intel_pebs_constraints(). The PEBS event will return immediately after intel_pebs_constraints(). So it's impossible to filter branches for PEBS events.
This patch moves intel_shared_regs_constraints() ahead of intel_pebs_constraints().
We can safely do that because the intel_shared_regs_constraints() function only returns empty constraint if its rejecting the event, otherwise it returns NULL such that we continue calling intel_pebs_constraints() and x86_get_event_constraint().
Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1427467105-9260-1-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/cpu/perf_event_intel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 498b6d9..40898ab 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1649,11 +1649,11 @@ intel_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event if (c) return c; - c = intel_pebs_constraints(event); + c = intel_shared_regs_constraints(cpuc, event); if (c) return c; - c = intel_shared_regs_constraints(cpuc, event); + c = intel_pebs_constraints(event); if (c) return c;
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