[LTP] [PATCH 1/1] tst_pids.c: fix fork failure on small memory systems

[Cyril Hrubis]

Hi!
>  lib/tst_pid.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/tst_pid.c b/lib/tst_pid.c
> index 21cadef2a..3fb3f39ad 100644
> --- a/lib/tst_pid.c
> +++ b/lib/tst_pid.c
> @@ -31,6 +31,7 @@
>  #include "tst_safe_macros.h"
>  
>  #define PID_MAX_PATH "/proc/sys/kernel/pid_max"
> +#define THREADS_MAX_PATH "/proc/sys/kernel/threads-max"
>  #define CGROUPS_V1_SLICE_FMT "/sys/fs/cgroup/pids/user.slice/user-%d.slice/pids.max"
>  #define CGROUPS_V2_SLICE_FMT "/sys/fs/cgroup/user.slice/user-%d.slice/pids.max"
>  /* Leave some available processes for the OS */
> @@ -113,7 +114,7 @@ static int get_session_pids_limit(void (*cleanup_fn) (void))
>  int tst_get_free_pids_(void (*cleanup_fn) (void))
>  {
>  	FILE *f;
> -	int rc, used_pids, max_pids, max_session_pids;
> +	int rc, used_pids, max_pids, max_session_pids, max_threads;
>  
>  	f = popen("ps -eT | wc -l", "r");
>  	if (!f) {
> @@ -129,6 +130,8 @@ int tst_get_free_pids_(void (*cleanup_fn) (void))
>  	}
>  
>  	SAFE_FILE_SCANF(cleanup_fn, PID_MAX_PATH, "%d", &max_pids);
> +	SAFE_FILE_SCANF(cleanup_fn, THREADS_MAX_PATH, "%d", &max_threads);
> +	max_pids = (max_pids < max_threads) ? max_pids : max_threads;

BTW: We do have a MIN() macro definition in tst_minmax.h header so we
     can just do max_pids = MIN(max_pids, max_threads);

>  	max_session_pids = get_session_pids_limit(cleanup_fn);
>  	if ((max_session_pids > 0) && (max_session_pids < max_pids))

Otherwise:

Reviewed-by: Cyril Hrubis <chrubis@suse.cz>

-- 
Cyril Hrubis
chrubis@suse.cz