Messages in this thread | | | Date | Fri, 4 Oct 2013 12:55:35 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH 0/7] perf, x86: Reduce lbr_sel_map size |
| |
On Thu, Sep 26, 2013 at 04:28:06PM +0800, Yan, Zheng wrote: > 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 main change since previous patch series is: > Patch 3 introduces PMU context switch callback, and uses the callback to > unify the flush branch stack codeo. > > Patch 4 uses the context switch callback to save/restore the LBR stack.
From what I can tell this is the exact same drivel I rejected earlier.
Same shitty changelogs, same shitty code.
Do not waste my time like this.
| |