From 6d461a4fe7896faa1aec5a5417888cf179e46b9f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Mon, 22 Feb 2016 01:12:47 -0300 Subject: Linux-libre 4.4.2-gnu --- mm/backing-dev.c | 2 +- mm/zsmalloc.c | 14 +++++++++++++- 2 files changed, 14 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 7340353f8..cbe6f0b96 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -989,7 +989,7 @@ long wait_iff_congested(struct zone *zone, int sync, long timeout) * here rather than calling cond_resched(). */ if (current->flags & PF_WQ_WORKER) - schedule_timeout(1); + schedule_timeout_uninterruptible(1); else cond_resched(); diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 9f15bdd91..fc083996e 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -309,7 +309,12 @@ static void free_handle(struct zs_pool *pool, unsigned long handle) static void record_obj(unsigned long handle, unsigned long obj) { - *(unsigned long *)handle = obj; + /* + * lsb of @obj represents handle lock while other bits + * represent object value the handle is pointing so + * updating shouldn't do store tearing. + */ + WRITE_ONCE(*(unsigned long *)handle, obj); } /* zpool driver */ @@ -1635,6 +1640,13 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class, free_obj = obj_malloc(d_page, class, handle); zs_object_copy(free_obj, used_obj, class); index++; + /* + * record_obj updates handle's value to free_obj and it will + * invalidate lock bit(ie, HANDLE_PIN_BIT) of handle, which + * breaks synchronization using pin_tag(e,g, zs_free) so + * let's keep the lock bit. + */ + free_obj |= BIT(HANDLE_PIN_BIT); record_obj(handle, free_obj); unpin_tag(handle); obj_free(pool, class, used_obj); -- cgit v1.2.3