From: Kan Liang <kan.liang@intel.com>
To: a.p.zijlstra@chello.nl, eranian@google.com
Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, paulus@samba.org,
acme@kernel.org, jolsa@redhat.com, ak@linux.intel.com,
Kan Liang <kan.liang@intel.com>,
"Yan, Zheng" <zheng.z.yan@intel.com>
Subject: [PATCH V6 13/17] perf, x86: enable LBR callstack when recording callchain
Date: Sun, 19 Oct 2014 17:55:08 -0400 [thread overview]
Message-ID: <1413755712-8259-14-git-send-email-kan.liang@intel.com> (raw)
In-Reply-To: <1413755712-8259-1-git-send-email-kan.liang@intel.com>
Only enable LBR callstack when user requires fp callgraph. The feature
is not available when PERF_SAMPLE_BRANCH_STACK or PERF_SAMPLE_STACK_USER
is required.
Also, this feature only affects how to get user callchain. The kernel
callchain is always got by frame pointers.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
---
arch/x86/kernel/cpu/perf_event.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 9656b9e..b3256a3 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -424,10 +424,24 @@ int x86_pmu_hw_config(struct perf_event *event)
if (!event->attr.exclude_kernel)
*br_type |= PERF_SAMPLE_BRANCH_KERNEL;
}
- }
+ } else if (x86_pmu_has_lbr_callstack() &&
+ (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) &&
+ !(event->attr.sample_type & PERF_SAMPLE_STACK_USER) &&
+ !has_branch_stack(event) &&
+ !event->attr.exclude_user &&
+ (event->attach_state & PERF_ATTACH_TASK)) {
+ /*
+ * user did not specify branch_sample_type,
+ * try using the LBR call stack facility to
+ * record call chains of user program.
+ */
+ event->attr.branch_sample_type =
+ PERF_SAMPLE_BRANCH_USER |
+ PERF_SAMPLE_BRANCH_CALL_STACK;
- if (event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK)
+ /* needs PMU specific data to save LBR stack */
event->attach_state |= PERF_ATTACH_TASK_DATA;
+ }
/*
* Generate PMC IRQs:
--
1.8.3.2
next prev parent reply other threads:[~2014-10-19 22:07 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-19 21:54 [PATCH V6 00/17] perf, x86: Haswell LBR call stack support Kan Liang
2014-10-19 21:54 ` [PATCH V6 01/17] perf, x86: Reduce lbr_sel_map size Kan Liang
2014-10-24 9:39 ` Peter Zijlstra
2014-11-04 1:07 ` Liang, Kan
2014-11-04 7:14 ` Peter Zijlstra
2014-11-04 7:16 ` Peter Zijlstra
2014-10-19 21:54 ` [PATCH V6 02/17] perf, core: introduce pmu context switch callback Kan Liang
2014-10-19 21:54 ` [PATCH V6 03/17] perf, x86: use context switch callback to flush LBR stack Kan Liang
2014-10-19 21:54 ` [PATCH V6 04/17] perf, x86: Basic Haswell LBR call stack support Kan Liang
2014-10-19 21:55 ` [PATCH V6 05/17] perf, core: pmu specific data for perf task context Kan Liang
2014-10-19 21:55 ` [PATCH V6 06/17] perf, core: always switch pmu specific data during context switch Kan Liang
2014-10-19 21:55 ` [PATCH V6 07/17] perf, x86: allocate space for storing LBR stack Kan Liang
2014-10-19 21:55 ` [PATCH V6 08/17] perf, x86: track number of events that use LBR callstack Kan Liang
2014-10-19 21:55 ` [PATCH V6 09/17] perf, x86: Save/resotre LBR stack during context switch Kan Liang
2014-10-19 21:55 ` [PATCH V6 10/17] perf, core: simplify need branch stack check Kan Liang
2014-10-19 21:55 ` [PATCH V6 11/17] perf, core: expose LBR call stack to user perf tool Kan Liang
2014-10-19 21:55 ` [PATCH V6 12/17] perf, x86: re-organize code that implicitly enables LBR/PEBS Kan Liang
2014-10-19 21:55 ` Kan Liang [this message]
2014-10-24 13:39 ` [PATCH V6 13/17] perf, x86: enable LBR callstack when recording callchain Jiri Olsa
2014-10-24 14:49 ` Liang, Kan
2014-10-19 21:55 ` [PATCH V6 14/17] perf, x86: disable FREEZE_LBRS_ON_PMI when LBR operates in callstack mode Kan Liang
2014-10-19 21:55 ` [PATCH V6 15/17] perf, x86: Discard zero length call entries in LBR call stack Kan Liang
2014-10-19 21:55 ` [PATCH V6 16/17] perf tools: handle LBR call stack data Kan Liang
2014-10-19 21:55 ` [PATCH V6 17/17] perf tools: choose to dump callchain from LBR and FP Kan Liang
2014-10-24 13:36 ` Jiri Olsa
2014-10-24 13:55 ` Jiri Olsa
2014-10-24 15:20 ` Liang, Kan
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