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From: "Yan, Zheng" <zheng.z.yan@intel.com>
To: mingo@kernel.org
Cc: linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl,
	akpm@linux-foundation.org, acme@redhat.com, eranian@google.com,
	namhyung@kernel.org, "Yan, Zheng" <zheng.z.yan@intel.com>
Subject: [PATCH 0/7] perf, x86: Haswell LBR call stack support
Date: Wed, 30 Jan 2013 14:30:50 +0800	[thread overview]
Message-ID: <1359527457-6837-1-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

The patch series depends on Andi's "Basic perf PMU support for Haswell v1" 

Available from
    https://github.com/ukernel/linux.git hws/pmu4

Regards
Yan, Zheng

             reply	other threads:[~2013-01-30  6:31 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-30  6:30 Yan, Zheng [this message]
2013-01-30  6:30 ` [PATCH 1/7] perf, x86: Reduce lbr_sel_map size Yan, Zheng
2013-01-30  6:30 ` [PATCH 2/7] perf, x86: Basic Haswell LBR call stack support Yan, Zheng
2013-01-30  6:30 ` [PATCH 3/7] perf, x86: Introduce x86 special perf event context Yan, Zheng
2013-01-30  6:30 ` [PATCH 4/7] perf, x86: Save/resotre LBR stack during context switch Yan, Zheng
2013-01-30  6:30 ` [PATCH 5/7] perf, core: Pass perf_sample_data to perf_callchain() Yan, Zheng
2013-01-30  6:30 ` [PATCH 6/7] perf, x86: Use LBR call stack to get user callchain Yan, Zheng
2013-01-30  6:30 ` [PATCH 7/7] perf, x86: Discard zero length call entries in LBR call stack Yan, Zheng
2013-06-25  8:47 [PATCH 0/7] perf, x86: Haswell LBR call stack support Yan, Zheng
2013-06-25 12:40 ` Stephane Eranian
2013-06-25 15:27   ` Andi Kleen
2013-06-25 15:30 ` Andi Kleen
2013-06-26 11:54 ` Peter Zijlstra
2013-06-26 16:40   ` Andi Kleen
2013-06-26 16:48   ` Stephane Eranian
2013-06-27  8:07     ` Yan, Zheng
2013-06-26 12:07 ` Peter Zijlstra
2013-06-26 16:59   ` Andi Kleen
2013-06-26 17:11     ` Peter Zijlstra

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