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Date:   Thu, 23 Nov 2023 11:42:18 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Leo Yan <leo.yan@linaro.org>
Cc:     Adrian Hunter <adrian.hunter@intel.com>,
        James Clark <james.clark@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        John Garry <john.g.garry@oracle.com>,
        Will Deacon <will@kernel.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@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Ian Rogers <irogers@google.com>, coresight@lists.linaro.org,
        linux-arm-kernel@lists.infradead.org,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 1/2] perf auxtrace: Add 'T' itrace option for
 timestamp trace
Message-ID: <ZV9kypSaAZNvaP1X@kernel.org>
References: <20231014074513.1668000-1-leo.yan@linaro.org>
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 <ZUlgM8pgf19UeyM9@kernel.org>
 <2940af18-8bcd-4456-a8ed-e77cade1b160@intel.com>
 <20231107094852.GA656098@leoy-yangtze.lan>
 <6fc8bc4c-abc3-45d5-a8c8-045f91adfebf@intel.com>
 <20231107141808.GD656098@leoy-yangtze.lan>
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Em Tue, Nov 07, 2023 at 10:18:08PM +0800, Leo Yan escreveu:
> On Tue, Nov 07, 2023 at 12:16:25PM +0200, Adrian Hunter wrote:
> 
> [...]
> 
> > >>>> "If users know" <- how would users know?  Could the kernel
> > >>>> or tools also figure it out?
> > >>>
> > >>> Adrian, I'm trying to go all the outstanding patches, do you still have
> > >>> any issues with this series?
> > >>
> > >> No, although the question wasn't actually answered.  I presume users
> > >> just have to try the 'T' option and see if it helps.
> > > 
> > > Sometimes, users are software developers in SoC companies, they can
> > > know well for the hardware design but are confused why current
> > > implementation cannot use timestamp trace.  This is the main reason
> > > I sent this patch set.
> > > 
> > > An example hardware platform is DB410c [1], we know its CoreSight can
> > > support timestamp trace, but if without this adding option 'T', we
> > > have no chance to use it due to it its CPU arch is prior to Armv8.4.
> > 
> > perf config might be better than an itrace option, but you decide.
> 
> I understand perf config is a better approach due to users don't need
> to bother inputting options after set it once.  I will look at it and
> respin new patch set.
> 
> Thanks for suggestion!

Thanks, applied.

- Arnaldo