[LTP] [PATCH v1] Fix synchronization problem with dio tests

[Cyril Hrubis]

Hi!
> When system is really fast processing I/O syscalls, multiple childrean
> running I/O operations might lock the parent, causing
> tst_reap_childrean() to stuck. By adding a small usleep at the
> end of the reading I/O operations, which are used by dio_append and
> dio_read tests, we ensure that system has enough breath to end tests
> correctly and to process children exit.

This does smell like a kernel bug to be honest.

Which test is this? How to reproduce?

> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
>  testcases/kernel/io/ltp-aiodio/common.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/testcases/kernel/io/ltp-aiodio/common.h b/testcases/kernel/io/ltp-aiodio/common.h
> index 200bbe18e..281072c3b 100644
> --- a/testcases/kernel/io/ltp-aiodio/common.h
> +++ b/testcases/kernel/io/ltp-aiodio/common.h
> @@ -90,6 +90,8 @@ static inline void io_read(const char *filename, int filesize, volatile int *run
>  			if (!*run_child || !tst_remaining_runtime())
>  				goto exit;
>  		}
> +
> +		usleep(100);
>  	}
>  
>  exit:
> @@ -121,6 +123,8 @@ static inline void io_read_eof(const char *filename, volatile int *run_child)
>  				break;
>  			}
>  		}
> +
> +		usleep(100);
>  	}
>  
>  	SAFE_CLOSE(fd);
> -- 
> 2.35.3
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

-- 
Cyril Hrubis
chrubis@suse.cz