linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Leo Yan <leo.yan@linaro.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mike Leach <mike.leach@linaro.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Kan Liang <kan.liang@linux.intel.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, Al Grant <al.grant@arm.com>
Subject: Re: [PATCH 1/2] perf cs-etm: Fix corrupt data after perf inject from
Date: Thu, 27 Aug 2020 14:53:54 -0600	[thread overview]
Message-ID: <20200827205354.GE22307@xps15> (raw)
In-Reply-To: <20200819084751.17686-1-leo.yan@linaro.org>

Hi Leo and Al,

On Wed, Aug 19, 2020 at 04:47:50PM +0800, Leo Yan wrote:
> From: Al Grant <al.grant@arm.com>
> 
> Commit 42bbabed09ce ("perf tools: Add hw_idx in struct branch_stack")
> changed the format of branch stacks in perf samples. When samples use
> this new format, a flag must be set in the corresponding event.
> Synthesized branch stacks generated from CoreSight ETM trace were using
> the new format, but not setting the event attribute, leading to
> consumers seeing corrupt data. This patch fixes the issue by setting the
> event attribute to indicate use of the new format.
> 
> Fixes: 42bbabed09ce ("perf tools: Add hw_idx in struct branch_stack")
> Signed-off-by: Al Grant <al.grant@arm.com>
> Reviewed-by: Andrea Brunato <andrea.brunato@arm.com>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> ---
>  tools/perf/util/cs-etm.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index c283223fb31f..a2a369e2fbb6 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -1344,8 +1344,15 @@ static int cs_etm__synth_events(struct cs_etm_auxtrace *etm,
>  		attr.sample_type &= ~(u64)PERF_SAMPLE_ADDR;
>  	}
>  
> -	if (etm->synth_opts.last_branch)
> +	if (etm->synth_opts.last_branch) {
>  		attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
> +		/*
> +		 * We don't use the hardware index, but the sample generation
> +		 * code uses the new format branch_stack with this field,
> +		 * so the event attributes must indicate that it's present.
> +		 */
> +		attr.branch_sample_type |= PERF_SAMPLE_BRANCH_HW_INDEX;
> +	}

I've see this patch before...  I thought it had been merged - what happened?

Thanks,
Mathieu

>  
>  	if (etm->synth_opts.instructions) {
>  		attr.config = PERF_COUNT_HW_INSTRUCTIONS;
> -- 
> 2.17.1
> 

  parent reply	other threads:[~2020-08-27 20:54 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-19  8:47 [PATCH 1/2] perf cs-etm: Fix corrupt data after perf inject from Leo Yan
2020-08-19  8:47 ` [PATCH 2/2] perf intel-pt: " Leo Yan
2020-08-24 12:41   ` Adrian Hunter
2020-08-31 20:38   ` Mathieu Poirier
2020-09-01 14:53     ` Arnaldo Carvalho de Melo
2020-08-27 20:53 ` Mathieu Poirier [this message]
2020-08-31  0:04   ` [PATCH 1/2] perf cs-etm: " Leo Yan
2020-09-01 14:54     ` Arnaldo Carvalho de Melo
2020-09-02  0:39       ` Leo Yan
2020-09-02  1:47         ` Arnaldo Carvalho de Melo
2020-09-02  2:12           ` Leo Yan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200827205354.GE22307@xps15 \
    --to=mathieu.poirier@linaro.org \
    --cc=acme@kernel.org \
    --cc=adrian.hunter@intel.com \
    --cc=ak@linux.intel.com \
    --cc=al.grant@arm.com \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=jolsa@redhat.com \
    --cc=kan.liang@linux.intel.com \
    --cc=leo.yan@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mike.leach@linaro.org \
    --cc=mingo@redhat.com \
    --cc=namhyung@kernel.org \
    --cc=peterz@infradead.org \
    --cc=suzuki.poulose@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).