diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 1715e34b91af..e506e365d6f1 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7191,6 +7191,11 @@ static DEFINE_STATIC_KEY_FALSE(zones_with_unaccepted_pages); static bool lazy_accept = true; +void unaccepted_cleanup_work(struct work_struct *work) +{ + static_branch_dec(&zones_with_unaccepted_pages); +} + static int __init accept_memory_parse(char *p) { if (!strcmp(p, "lazy")) { @@ -7229,8 +7234,27 @@ static void __accept_page(struct zone *zone, unsigned long *flags, __free_pages_ok(page, MAX_PAGE_ORDER, FPI_TO_TAIL); - if (last) - static_branch_dec(&zones_with_unaccepted_pages); + if (last) { + /* + * There are two corner cases: + * + * - If allocation occurs during the CPU bring up, + * static_branch_dec() cannot be used directly as + * it causes a deadlock on cpu_hotplug_lock. + * + * Instead, use schedule_work() to prevent deadlock. + * + * - If allocation occurs before workqueues are initialized, + * static_branch_dec() should be called directly. + * + * Workqueues are initialized before CPU bring up, so this + * will not conflict with the first scenario. + */ + if (system_wq) + schedule_work(&zone->unaccepted_cleanup); + else + unaccepted_cleanup_work(&zone->unaccepted_cleanup); + } } void accept_page(struct page *page) |