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@kernel.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

 tools/testing/selftests/arm64/fp/fp-stress.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)
---
base-commit: 8e929cb546ee42c9a61d24fae60605e9e3192354
change-id: 20241028-arm64-fp-stress-interval-8f5e62c06e12

Best regards,
-- 
Mark Brown <broonie@kernel.org>

On Wed, 30 Oct 2024 00:02:01 +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.
> 
> [...]

Applied to arm64 (for-next/kselftest), thanks!

[1/2] kselftest/arm64: Increase frequency of signal delivery in fp-stress
      https://git.kernel.org/arm64/c/a3590d71a1ac
[2/2] kselftest/arm64: Poll less often while waiting for fp-stress children
      https://git.kernel.org/arm64/c/161e9925053c

-- 
Catalin

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@kernel.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@kernel.org>

for both.

Will