[tip:perf/core] perf/x86: Add support for sampling PEBS machine state registers

From: tip-bot for Stephane Eranian
Date: Sun Nov 16 2014 - 07:36:34 EST


Commit-ID: aea48559ac454a065244d3eff0c94cc8af9c553e
Gitweb: http://git.kernel.org/tip/aea48559ac454a065244d3eff0c94cc8af9c553e
Author: Stephane Eranian <eranian@xxxxxxxxxx>
AuthorDate: Wed, 24 Sep 2014 13:48:38 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 16 Nov 2014 11:41:58 +0100

perf/x86: Add support for sampling PEBS machine state registers

PEBS can capture machine state regs at retiremnt of the sampled
instructions. When precise sampling is enabled on an event, PEBS
is used, so substitute the interrupted state with the PEBS state.
Note that not all registers are captured by PEBS. Those missing
are replaced by the interrupt state counter-parts.

Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1411559322-16548-3-git-send-email-eranian@xxxxxxxxxx
Cc: cebbert.lkml@xxxxxxxxx
Cc: jolsa@xxxxxxxxxx
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel_ds.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 3c5d5c1..495ae97 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -886,6 +886,29 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
regs.bp = pebs->bp;
regs.sp = pebs->sp;

+ if (sample_type & PERF_SAMPLE_REGS_INTR) {
+ regs.ax = pebs->ax;
+ regs.bx = pebs->bx;
+ regs.cx = pebs->cx;
+ regs.dx = pebs->dx;
+ regs.si = pebs->si;
+ regs.di = pebs->di;
+ regs.bp = pebs->bp;
+ regs.sp = pebs->sp;
+
+ regs.flags = pebs->flags;
+#ifndef CONFIG_X86_32
+ regs.r8 = pebs->r8;
+ regs.r9 = pebs->r9;
+ regs.r10 = pebs->r10;
+ regs.r11 = pebs->r11;
+ regs.r12 = pebs->r12;
+ regs.r13 = pebs->r13;
+ regs.r14 = pebs->r14;
+ regs.r15 = pebs->r15;
+#endif
+ }
+
if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format >= 2) {
regs.ip = pebs->real_ip;
regs.flags |= PERF_EFLAGS_EXACT;
--
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