From e2a0b786c50cf4f0c3abfcd05888ae583c98cf25 Mon Sep 17 00:00:00 2001 From: Connor O'Brien Date: Fri, 2 Jun 2023 22:02:09 +0000 Subject: [PATCH] torture: Support randomized shuffling for proxy exec testing Currently shuffling sets the same cpu affinities for all tasks, which makes us less likely to hit paths involving migrating blocked tasks onto a cpu where they can't run. This patch adds an element of randomness to allow affinities of different writer tasks to diverge. This has helped uncover issues in testing with Proxy Execution Cc: "Paul E. McKenney" Cc: Josh Triplett Cc: Joel Fernandes Cc: Juri Lelli Cc: Valentin Schneider Cc: Dietmar Eggemann Cc: kernel-team@android.com Signed-off-by: Connor O'Brien Signed-off-by: John Stultz Acked-by: Davidlohr Bueso Signed-off-by: Paul E. McKenney --- kernel/torture.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/kernel/torture.c b/kernel/torture.c index 1a0519b836ac..8be83fdc6be1 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -54,6 +54,9 @@ module_param(verbose_sleep_frequency, int, 0444); static int verbose_sleep_duration = 1; module_param(verbose_sleep_duration, int, 0444); +static int random_shuffle; +module_param(random_shuffle, int, 0444); + static char *torture_type; static int verbose; @@ -518,6 +521,7 @@ static void torture_shuffle_task_unregister_all(void) */ static void torture_shuffle_tasks(void) { + DEFINE_TORTURE_RANDOM(rand); struct shuffle_task *stp; cpumask_setall(shuffle_tmp_mask); @@ -537,8 +541,10 @@ static void torture_shuffle_tasks(void) cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); mutex_lock(&shuffle_task_mutex); - list_for_each_entry(stp, &shuffle_task_list, st_l) - set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); + list_for_each_entry(stp, &shuffle_task_list, st_l) { + if (!random_shuffle || torture_random(&rand) & 0x1) + set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); + } mutex_unlock(&shuffle_task_mutex); cpus_read_unlock();