diff options
| -rw-r--r-- | mm/page_alloc.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 610a3db680ae..8af0d4fa683d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2341,7 +2341,16 @@ void drain_local_pages(struct zone *zone) static void drain_local_pages_wq(struct work_struct *work) { + /* + * drain_all_pages doesn't use proper cpu hotplug protection so + * we can race with cpu offline when the WQ can move this from + * a cpu pinned worker to an unbound one. We can operate on a different + * cpu which is allright but we also have to make sure to not move to + * a different one. + */ + preempt_disable(); drain_local_pages(NULL); + preempt_enable(); } /* @@ -2366,11 +2375,6 @@ void drain_all_pages(struct zone *zone) if (current->flags & PF_WQ_WORKER) return; - /* - * As this can be called from reclaim context, do not reenter reclaim. - * An allocation failure can be handled, it's simply slower - */ - get_online_cpus(); works = alloc_percpu_gfp(struct work_struct, GFP_ATOMIC); /* @@ -2421,7 +2425,6 @@ void drain_all_pages(struct zone *zone) flush_work(&work); } } - put_online_cpus(); } #ifdef CONFIG_HIBERNATION |