Messages in this thread | | | Subject | Re: [PATCH v5 2/9] coresight: tmc-etr: Add barrier after updating AUX ring buffer | From | Suzuki K Poulose <> | Date | Tue, 14 Sep 2021 10:08:49 +0100 |
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On 29/08/2021 11:55, Leo Yan wrote: > Hi Mathieu, Suzuki, > > On Mon, Aug 09, 2021 at 07:14:00PM +0800, Leo Yan wrote: >> Since a memory barrier is required between AUX trace data store and >> aux_head store, and the AUX trace data is filled with memcpy(), it's >> sufficient to use smp_wmb() so can ensure the trace data is visible >> prior to updating aux_head. >> >> Signed-off-by: Leo Yan <leo.yan@linaro.org> >> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> > > Could you pick up patches 02 and 03 in this series? Please note, > patch 02 has the review tag from Suzuki, but I didn't receive the > review tag for patch 03. > > If anything need to follow up, just let me know. Thanks!
I have picked up both the patches.
Thanks Suzuki
> >> --- >> drivers/hwtracing/coresight/coresight-tmc-etr.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c >> index acdb59e0e661..13fd1fc730ed 100644 >> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c >> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c >> @@ -1563,6 +1563,14 @@ tmc_update_etr_buffer(struct coresight_device *csdev, >> */ >> if (etr_perf->snapshot) >> handle->head += size; >> + >> + /* >> + * Ensure that the AUX trace data is visible before the aux_head >> + * is updated via perf_aux_output_end(), as expected by the >> + * perf ring buffer. >> + */ >> + smp_wmb(); >> + >> out: >> /* >> * Don't set the TRUNCATED flag in snapshot mode because 1) the >> -- >> 2.25.1 >>
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