From: Florian Weimer <fweimer@redhat.com>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: libc-alpha@sourceware.org, Aurelien Jarno <aurelien@aurel32.net>
Subject: Re: [PATCH] misc: tst-poll: Proper synchronize with child before sending the signal
Date: Fri, 26 Jan 2024 13:02:28 +0100 [thread overview]
Message-ID: <87plxo4817.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20240126112341.2286758-1-adhemerval.zanella@linaro.org> (Adhemerval Zanella's message of "Fri, 26 Jan 2024 08:23:41 -0300")
* Adhemerval Zanella:
> When running the testsuite in parallel, for instance running make -j
> $(nproc) check, occasionally tst-epoll fails with a timeout. It happens
> because it sometimes takes a bit more than 10ms for the process to get
> cloned and blocked by the syscall. In that case the signal is
> sent to early, and the test fails with a timeout.
>
> Checked on x86_64-linux-gnu.
> ---
> sysdeps/unix/sysv/linux/tst-epoll.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/sysdeps/unix/sysv/linux/tst-epoll.c b/sysdeps/unix/sysv/linux/tst-epoll.c
> index 3b38beae6e..545f506faa 100644
> --- a/sysdeps/unix/sysv/linux/tst-epoll.c
> +++ b/sysdeps/unix/sysv/linux/tst-epoll.c
> @@ -22,7 +22,7 @@
> #include <support/support.h>
> #include <support/xsignal.h>
> #include <support/xunistd.h>
> -#include <support/xtime.h>
> +#include <support/process_state.h>
> #include <stdlib.h>
> #include <sys/epoll.h>
>
> @@ -97,8 +97,8 @@ test_epoll_basic (epoll_wait_check_t epoll_wait_check)
> xclose (fds[0][0]);
> xclose (fds[1][1]);
>
> - /* Wait some time so child is blocked on the syscall. */
> - nanosleep (&(struct timespec) {0, 10000000}, NULL);
> + /* Wait until child is blocked on epoll_wait. */
> + support_process_state_wait (p, support_process_state_sleeping);
> TEST_COMPARE (kill (p, SIGUSR1), 0);
>
> int e = epoll_wait_check (efd, &event, 1, 500000000, &ss);
Looks okay. I don't see any blocking system calls between the fork and
the epoll_wait call.
Thanks,
Florian
next prev parent reply other threads:[~2024-01-26 12:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-26 11:23 Adhemerval Zanella
2024-01-26 12:02 ` Florian Weimer [this message]
2024-02-09 17:54 ` Aurelien Jarno
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