From: "Yan, Zheng" <zheng.z.yan@intel.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, a.p.zijlstra@chello.nl, eranian@google.com,
andi@firstfloor.org, "Yan, Zheng" <zheng.z.yan@intel.com>
Subject: [PATCH v2 0/7] perf, x86: Haswell LBR call stack support
Date: Mon, 1 Jul 2013 15:23:00 +0800 [thread overview]
Message-ID: <1372663387-11754-1-git-send-email-zheng.z.yan@intel.com> (raw)
From: "Yan, Zheng" <zheng.z.yan@intel.com>
Haswell has a new feature that utilizes the existing Last Branch Record
facility to record call chains. When the feature is enabled, function
call will be collected as normal, but as return instructions are executed
the last captured branch record is popped from the on-chip LBR registers.
The LBR call stack facility can help perf to get call chains of progam
without frame pointer. When perf tool requests PERF_SAMPLE_CALLCHAIN +
PERF_SAMPLE_BRANCH_USER, this feature is dynamically enabled by default.
This feature can be disabled/enabled through an attribute file in the cpu
pmu sysfs directory.
The LBR call stack has following known limitations
1. Zero length calls are not filtered out by hardware
2. Exception handing such as setjmp/longjmp will have calls/returns
not match
3. Pushing different return address onto the stack will have
calls/returns not match
These patches are based upon tip/perf/core
Regards
Yan, Zheng
---
Changes since v1
- more comments for why FREEZE_LBRS_ON_PMI does not work
- don't save/restore LBR during context switches if LBR are used by
CPU events
- change mode of /sys/devices/cpu/lbr_callstack to 0644
next reply other threads:[~2013-07-01 7:23 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-01 7:23 Yan, Zheng [this message]
2013-07-01 7:23 ` [PATCH v2 1/7] perf, x86: Reduce lbr_sel_map size Yan, Zheng
2013-07-01 7:23 ` [PATCH v2 2/7] perf, x86: Basic Haswell LBR call stack support Yan, Zheng
2013-07-01 7:23 ` [PATCH v2 3/7] perf, x86: Introduce x86 special perf event context Yan, Zheng
2013-07-04 12:41 ` Peter Zijlstra
2013-07-05 3:19 ` Yan, Zheng
2013-07-05 12:45 ` Peter Zijlstra
2013-07-08 8:51 ` Yan, Zheng
2013-07-01 7:23 ` [PATCH v2 4/7] perf, x86: Save/resotre LBR stack during context switch Yan, Zheng
2013-07-04 9:57 ` Peter Zijlstra
2013-07-04 11:39 ` Yan, Zheng
2013-07-04 13:44 ` Andi Kleen
2013-07-04 14:00 ` Peter Zijlstra
2013-07-10 17:57 ` Andi Kleen
2013-07-04 12:44 ` Peter Zijlstra
2013-07-04 12:45 ` Peter Zijlstra
2013-07-05 5:36 ` Yan, Zheng
2013-07-05 8:15 ` Peter Zijlstra
2013-07-05 8:51 ` Yan, Zheng
2013-07-05 12:31 ` Peter Zijlstra
2013-08-08 6:18 ` Yan, Zheng
2013-07-01 7:23 ` [PATCH v2 5/7] perf, core: Pass perf_sample_data to perf_callchain() Yan, Zheng
2013-07-01 7:23 ` [PATCH v2 6/7] perf, x86: Use LBR call stack to get user callchain Yan, Zheng
2013-07-01 7:23 ` [PATCH v2 7/7] perf, x86: Discard zero length call entries in LBR call stack Yan, Zheng
-- strict thread matches above, loose matches on Subject: below --
2012-10-24 5:59 [PATCH V2 0/7] perf, x86: Haswell LBR call stack support Yan, Zheng
2012-10-24 8:49 ` Stephane Eranian
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