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

[Andrea Cervesato]

Hi!

On 1/29/24 16:01, Cyril Hrubis wrote:
> 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.
I thought the same at first, but I didn't find issues in the kernel. We 
can take a look deeper for sure.
> 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

Andrea