Re: [PATCH v1 0/4] perf cs-etm: Fix synthesizing instruction samples

From: Leo Yan <leo.yan@linaro.org>
To: Mathieu Poirier <mathieu.poirier@linaro.org>,
	Mike Leach <mike.leach@linaro.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	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>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Coresight ML <coresight@lists.linaro.org>,
	Robert Walker <robert.walker@arm.com>
Subject: Re: [PATCH v1 0/4] perf cs-etm: Fix synthesizing instruction samples
Date: Fri, 1 Nov 2019 10:10:55 +0800	[thread overview]
Message-ID: <20191101021055.GA26019@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <CANLsYkzaB2kU20ibuDJVokYeEEuR8wd7MoHzX9+UKnM0jNV1Jg@mail.gmail.com>

On Thu, Oct 31, 2019 at 11:14:15AM -0600, Mathieu Poirier wrote:
> On Thu, 24 Oct 2019 at 09:15, Leo Yan <leo.yan@linaro.org> wrote:
> >
> > This patch series is to address the issue for synthesizing instruction
> > samples, especially when the instruction sample period is small enough,
> > the current logic cannot synthesize multiple instruction samples within
> > one instruction range packet.
> >
> > To fix this issue, patch 0001 avoids to reset the last branches for
> > every instruction sample; if reset the last branches when every time
> > generate instruction sample, then the later samples in the same range
> > packet cannot use the last branches anymore.
> >
> > Patch 0002 is the main patch to fix the logic for synthesizing
> > instruction samples; it allows to handle different instruction periods.
> >
> > Patch 0003 is an optimization for copying last branches; it only copies
> > last branches once if the instruction samples share the same last
> > branches.
> >
> > Patch 0004 is a minor fix for unsigned variable comparison to zero.
> >
> > To verify my changing for synthesizing instruction samples, I added
> > some logs in the code, and reviewed the output log manually for
> > instuctions samples.  The below commands are tested on DB410c board:
> >
> >   # perf script --itrace=i2
> >   # perf script --itrace=i2li16
> >   # perf inject --itrace=i2il16 -i perf.data -o perf.data.new
> >   # perf inject --itrace=i100il16 -i perf.data -o perf.data.new
> >
> >
> > Leo Yan (4):
> >   perf cs-etm: Continuously record last branches
> >   perf cs-etm: Correct synthesizing instruction samples
> >   perf cs-etm: Optimize copying last branches
> >   perf cs-etm: Fix unsigned variable comparison to zero
> 
> I have reviewed and agree with the changes in this set but won't move
> forward until Mike has looked at patch 2/4.

Thanks a lot for reviewing, Mathieu.

Sorry I forgot to loop Mike in this patch set, and respin patch for v2
and have sent to mailing list.  @Mike, please review patch set v2 as
you received, Thanks!

Thanks,
Leo Yan