Re: [PATCH 2/2] perf tsc: Replace the compile-time TSC support check with a weak hook

[sashiko-bot@kernel.org]

> The "TSC support" subtest of the "Convert perf time to TSC" test decides
> whether the architecture is covered by matching compiler macros for
> x86_64, i386 and arm64.  That list has to be edited for every new
> architecture, and it can drift apart from the set of architectures that
> really provide a counter: util/tsc.c already ships a weak rdtsc() which
> an architecture overrides with a strong definition when it has one.
> 
> Add a weak arch__rdtsc_supported() next to the weak rdtsc(), let the
> test query it instead of the macros, and have x86, arm64 and riscv
> override it in the file where they implement rdtsc().  Support is then
> declared next to the counter it describes, and a caller can tell a stub
> apart from a real counter without keeping its own copy of the macro
> list.  This follows the pattern of the other optional per-architecture
> hooks in util/ such as get_cpuid_str().
> 
> x86 and arm64 keep the same behaviour, and riscv starts running the
> subtest because it gained rdtsc() in the previous patch.
> 
> Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260928094739.2605-1-cp0613@linux.alibaba.com?part=2