Messages in this thread | | | Subject | Re: [PATCH 09/12] perf_events: add hook to flush branch_stack on context switch (v2) | From | Peter Zijlstra <> | Date | Mon, 05 Dec 2011 22:37:54 +0100 |
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On Fri, 2011-10-14 at 14:37 +0200, Stephane Eranian wrote: > + /* > + * check if the context has at least one > + * event using PERF_SAMPLE_BRANCH_STACK > + */ > + if (cpuctx->ctx.nr_branch_stack > 0 > + && pmu->flush_branch_stack) { > + > + pmu = cpuctx->ctx.pmu; > + > + perf_ctx_lock(cpuctx, cpuctx->task_ctx); > + > + perf_pmu_disable(pmu); > + > + pmu->flush_branch_stack(); > + > + perf_pmu_enable(pmu); > + > + perf_ctx_unlock(cpuctx, cpuctx->task_ctx); > + } > + }
(what whitespace looks funny)
So all PMUs not supporting this branch stuff will fail to create a has_branch_stack() event, right? Thus all ctx with !0 nr_branch_stack support it. Doesn't this make the test for pmu->flush_branch_stack redundant?
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