linux-kernel - Re: [PATCH v2 0/2] kselftest/arm64: fp-stress signal delivery interval improvements

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Message-ID: <20241107112407.GB15424@willie-the-truck>
Date: Thu, 7 Nov 2024 11:24:08 +0000
From: Will Deacon <will@...nel.org>
To: Mark Brown <broonie@...nel.org>
Cc: Catalin Marinas <catalin.marinas@....com>,
	Shuah Khan <shuah@...nel.org>, Mark Rutland <mark.rutland@....com>,
	linux-arm-kernel@...ts.infradead.org,
	linux-kselftest@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 0/2] kselftest/arm64: fp-stress signal delivery
 interval improvements

On Wed, Oct 30, 2024 at 12:02:01AM +0000, Mark Brown wrote:
> One of the things that fp-stress does to stress the floating point
> context switching is send signals to the test threads it spawns.
> Currently we do this once per second but as suggested by Mark Rutland if
> we increase this we can improve the chances of triggering any issues
> with context switching the signal handling code.  Do a quick change to 
> increase the rate of signal delivery, trying to avoid excessive impact
> on emulated platforms, and a further change to mitigate the impact that
> this creates during startup.
> 
> Signed-off-by: Mark Brown <broonie@...nel.org>
> ---
> Changes in v2:
> - Minor clarifications in commit message and log output.
> - Link to v1: https://lore.kernel.org/r/20241029-arm64-fp-stress-interval-v1-0-db540abf6dd5@kernel.org
> 
> ---
> Mark Brown (2):
>       kselftest/arm64: Increase frequency of signal delivery in fp-stress
>       kselftest/arm64: Poll less often while waiting for fp-stress children

With these changes, I was easily able to reproduce the SVCR=0 bug so:

Acked-by: Will Deacon <will@...nel.org>

for both.

Will