Commit bf6d575e authored by Brendan Jackman's avatar Brendan Jackman Committed by Andrew Morton
Browse files

selftests/mm: don't fail uffd-stress if too many CPUs 

This calculation divides a fixed parameter by an environment-dependent
parameter i.e.  the number of CPUs.

The simple way to avoid machine-specific failures here is to just put a
cap on the max value of the latter.

Link: https://lkml.kernel.org/r/20250311-mm-selftests-v4-6-dec210a658f5@google.com


Signed-off-by: default avatarBrendan Jackman <jackmanb@google.com>
Suggested-by: default avatarMateusz Guzik <mjguzik@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent db0f1c13

tools/testing/selftests/mm/uffd-stress.c

+10 −1
Original line number Diff line number Diff line
@@ -435,6 +435,7 @@ static void sigalrm(int sig) 


int main(int argc, char **argv)

{

	unsigned long nr_cpus;

	size_t bytes;



	if (argc < 4)
@@ -453,7 +454,15 @@ int main(int argc, char **argv) 
		return KSFT_SKIP;

	}



	nr_parallel = sysconf(_SC_NPROCESSORS_ONLN);

	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);

	if (nr_cpus > 32) {

		/* Don't let calculation below go to zero. */

		ksft_print_msg("_SC_NPROCESSORS_ONLN (%lu) too large, capping nr_threads to 32\n",

			       nr_cpus);

		nr_parallel = 32;

	} else {

		nr_parallel = nr_cpus;

	}



	nr_pages_per_cpu = bytes / page_size / nr_parallel;

	if (!nr_pages_per_cpu) {