linux-kernel - Re: [PATCH v1] perf tests: Fix data symbol test with LTO builds

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Message-Id: <174145825623.807676.12586050400195682696.b4-ty@kernel.org>
Date: Sat, 08 Mar 2025 10:24:16 -0800
From: Namhyung Kim <namhyung@...nel.org>
To: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, 
 Arnaldo Carvalho de Melo <acme@...nel.org>, 
 Mark Rutland <mark.rutland@....com>, 
 Alexander Shishkin <alexander.shishkin@...ux.intel.com>, 
 Jiri Olsa <jolsa@...nel.org>, Adrian Hunter <adrian.hunter@...el.com>, 
 Kan Liang <kan.liang@...ux.intel.com>, James Clark <james.clark@...aro.org>, 
 linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org, 
 Ian Rogers <irogers@...gle.com>
Subject: Re: [PATCH v1] perf tests: Fix data symbol test with LTO builds

On Wed, 26 Feb 2025 15:01:09 -0800, Ian Rogers wrote:
> With LTO builds, although regular builds could also see this as
> all the code is in one file, the datasym workload can realize the
> buf1.reserved data is never accessed. The compiler moves the
> variable to bss and only keeps the data1 and data2 parts as
> separate variables. This causes the symbol check to fail in the
> test. Make the variable volatile to disable the more aggressive
> optimization. Rename the variable to make which buf1 in perf is
> being referred to.
> 
> [...]
Applied to perf-tools-next, thanks!

Best regards,
Namhyung