diff options
| -rw-r--r-- | include/linux/mmzone.h | 3 | ||||
| -rw-r--r-- | mm/internal.h | 1 | ||||
| -rw-r--r-- | mm/mm_init.c | 1 | ||||
| -rw-r--r-- | mm/page_alloc.c | 28 |
4 files changed, 31 insertions, 2 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 25e80b2ca7f4..4c95fcc9e9df 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -967,6 +967,9 @@ struct zone { #ifdef CONFIG_UNACCEPTED_MEMORY /* Pages to be accepted. All pages on the list are MAX_PAGE_ORDER */ struct list_head unaccepted_pages; + + /* To be called once the last page in the zone is accepted */ + struct work_struct unaccepted_cleanup; #endif /* zone flags, see below */ diff --git a/mm/internal.h b/mm/internal.h index 50c2f590b2d0..e9695baa5922 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1595,6 +1595,7 @@ unsigned long move_page_tables(struct pagetable_move_control *pmc); #ifdef CONFIG_UNACCEPTED_MEMORY void accept_page(struct page *page); +void unaccepted_cleanup_work(struct work_struct *work); #else /* CONFIG_UNACCEPTED_MEMORY */ static inline void accept_page(struct page *page) { diff --git a/mm/mm_init.c b/mm/mm_init.c index 84f14fa12d0d..9659689b8ace 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -1441,6 +1441,7 @@ static void __meminit zone_init_free_lists(struct zone *zone) #ifdef CONFIG_UNACCEPTED_MEMORY INIT_LIST_HEAD(&zone->unaccepted_pages); + INIT_WORK(&zone->unaccepted_cleanup, unaccepted_cleanup_work); #endif } 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) |