Messages in this thread | | | Date | Fri, 3 Sep 2021 10:27:08 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v5 bpf-next 1/3] perf: enable branch record for software events |
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On Thu, Sep 02, 2021 at 09:57:04AM -0700, Song Liu wrote:
> +static int > +intel_pmu_snapshot_branch_stack(struct perf_branch_entry *entries, unsigned int cnt) > +{ > + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); > + > + intel_pmu_disable_all(); > + intel_pmu_lbr_read(); > + cnt = min_t(unsigned int, cnt, x86_pmu.lbr_nr); > + > + memcpy(entries, cpuc->lbr_entries, sizeof(struct perf_branch_entry) * cnt); > + intel_pmu_enable_all(0); > + return cnt; > +}
Given this disables the PMI from 'random' contexts, should we not add IRQ disabling around this to avoid really bad behaviour?
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