Re: [PATCH i-g-t v1 1/1] lib/igt_core: flush output on each line

["Rudnicki, Piotr" <piotr.rudnicki@intel.com>]

On 3/25/2026 12:49 PM, Jan Sokolowski wrote:
> It was found while running tests that if a test launches threads with
> even more subthreads, some igt_debug calls might not print their lines.
> 
> Fflush after each line to make sure we see everything we want to see.
> 
> Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
LGTM,
Reviewed-by: Piotr Rudnicki <piotr.rudnicki@intel.com>
> ---
>   lib/igt_core.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/igt_core.c b/lib/igt_core.c
> index 65325f08d..ed4f48d86 100644
> --- a/lib/igt_core.c
> +++ b/lib/igt_core.c
> @@ -3294,10 +3294,8 @@ void igt_vlog(const char *domain, enum igt_log_level level, const char *format,
>   	pthread_mutex_lock(&print_mutex);
>   
>   	/* use stderr for warning messages and above */
> -	if (level >= IGT_LOG_WARN) {
> +	if (level >= IGT_LOG_WARN)
>   		file = stderr;
> -		fflush(stdout);
> -	}
>   	else
>   		file = stdout;
>   
> @@ -3309,6 +3307,11 @@ void igt_vlog(const char *domain, enum igt_log_level level, const char *format,
>   		_log_line_fprintf(file, "%s%s", thread_id, line);
>   	}
>   
> +	/* Ensure output is flushed explicitly, as concurrent test threads
> +	 * may otherwise cause messages to be dropped or reordered.
> +	 */
> +	fflush(file);
> +
>   	pthread_mutex_unlock(&print_mutex);
>   
>   out: