2023-11-20 11:14:12

by Ilpo Järvinen

Subject: [PATCH v2 01/26] selftests/resctrl: Don't use ctrlc_handler() outside signal handling

perf_event_open_llc_miss() calls ctrlc_handler() to cleanup if
perf_event_open() returns an error. Those cleanups, however, are not
the responsability of perf_event_open_llc_miss() and it thus interferes
unnecessarily with the usual cleanup pattern. Worse yet,
ctrlc_handler() calls exit() in the end preventing the ordinary cleanup
done in the calling function from executing.

ctrlc_handler() should only be used as a signal handler, not during
normal error handling.

Remove call to ctrlc_handler() from perf_event_open_llc_miss(). As
unmounting resctrlfs and test cleanup are already handled properly
by error rollbacks in the calling functions, no other changes are
necessary.

Suggested-by: Reinette Chatre <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
---
tools/testing/selftests/resctrl/cache.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
index bcbca356d56a..8aa6d67db978 100644
--- a/tools/testing/selftests/resctrl/cache.c
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -41,7 +41,6 @@ static int perf_event_open_llc_miss(pid_t pid, int cpu_no)
PERF_FLAG_FD_CLOEXEC);
if (fd_lm == -1) {
perror("Error opening leader");
- ctrlc_handler(0, NULL, NULL);
return -1;
}

--
2.30.2

2023-11-28 22:10:14

by Reinette Chatre

Subject: Re: [PATCH v2 01/26] selftests/resctrl: Don't use ctrlc_handler() outside signal handling

Hi Ilpo,

On 11/20/2023 3:13 AM, Ilpo Järvinen wrote:
> perf_event_open_llc_miss() calls ctrlc_handler() to cleanup if
> perf_event_open() returns an error. Those cleanups, however, are not
> the responsability of perf_event_open_llc_miss() and it thus interferes

responsibility

> unnecessarily with the usual cleanup pattern. Worse yet,
> ctrlc_handler() calls exit() in the end preventing the ordinary cleanup
> done in the calling function from executing.
>
> ctrlc_handler() should only be used as a signal handler, not during
> normal error handling.
>
> Remove call to ctrlc_handler() from perf_event_open_llc_miss(). As
> unmounting resctrlfs and test cleanup are already handled properly
> by error rollbacks in the calling functions, no other changes are
> necessary.
>
> Suggested-by: Reinette Chatre <[email protected]>
> Signed-off-by: Ilpo Järvinen <[email protected]>

Reviewed-by: Reinette Chatre <[email protected]>

Reinette