Messages in this thread Patch in this message | | | From | Alexandru Elisei <> | Subject | [PATCH v5 4/7] arm64: perf: Defer irq_work to IPI_IRQ_WORK | Date | Wed, 17 Jun 2020 12:38:48 +0100 |
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From: Julien Thierry <julien.thierry@arm.com>
perf_event_overflow() can queue an irq_work on the current PE, which is executed via an IPI. Move the processing of the irq_work from the PMU IRQ handler to the IPI handler, which gets executed immediately afterwards.
This also makes the IRQ handler NMI safe, because it removes the call to irq_work_run().
Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Julien Thierry <julien.thierry@arm.com> [Reworded commit] Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> --- arch/arm64/kernel/perf_event.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index a6195022be7d..cf1d92030790 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -750,20 +750,16 @@ static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu) if (!armpmu_event_set_period(event)) continue; + /* + * Perf event overflow will queue the processing of the event as + * an irq_work which will be taken care of in the handling of + * IPI_IRQ_WORK. + */ if (perf_event_overflow(event, &data, regs)) cpu_pmu->disable(event); } armv8pmu_start(cpu_pmu); - /* - * Handle the pending perf events. - * - * Note: this call *must* be run with interrupts disabled. For - * platforms that can have the PMU interrupts raised as an NMI, this - * will not work. - */ - irq_work_run(); - return IRQ_HANDLED; } -- 2.27.0
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