From d64f2fa064f8866802e23c8ec95d9d1f601480ee Mon Sep 17 00:00:00 2001 From: Juri Lelli Date: Thu, 8 Feb 2024 11:10:13 -0500 Subject: kernel/workqueue: Let rescuers follow unbound wq cpumask changes When workqueue cpumask changes are committed the associated rescuer (if one exists) affinity is not touched and this might be a problem down the line for isolated setups. Make sure rescuers affinity is updated every time a workqueue cpumask changes, so that rescuers can't break isolation. [longman: set_cpus_allowed_ptr() will block until the designated task is enqueued on an allowed CPU, no wake_up_process() needed. Also use the unbound_effective_cpumask() helper as suggested by Tejun.] Signed-off-by: Juri Lelli Signed-off-by: Waiman Long Signed-off-by: Tejun Heo --- kernel/workqueue.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index da124859a691..a24c7cfb80b4 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -5051,6 +5051,11 @@ static void apply_wqattrs_commit(struct apply_wqattrs_ctx *ctx) /* update node_nr_active->max */ wq_update_node_max_active(ctx->wq, -1); + /* rescuer needs to respect wq cpumask changes */ + if (ctx->wq->rescuer) + set_cpus_allowed_ptr(ctx->wq->rescuer->task, + unbound_effective_cpumask(ctx->wq)); + mutex_unlock(&ctx->wq->mutex); } -- cgit v1.2.3