On Wed 25-07-18 14:37:58, zhaowuyun@xxxxxxxxxxxx wrote: [...] > Change-Id: I36d9df7ccff77c589b7157225410269c675a8504 What is this? > Signed-off-by: zhaowuyun <zhaowuyun@xxxxxxxxxxxx> > --- > mm/vmscan.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 2740973..acede002 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -674,6 +674,12 @@ static int __remove_mapping(struct address_space *mapping, struct page *page, > BUG_ON(!PageLocked(page)); > BUG_ON(mapping != page_mapping(page)); > + /* > + * preemption must be disabled to protect current task preempted before > + * swapcache_free(swap) invoked by the task which do the > + * __read_swap_cache_async job on the same page > + */ > + preempt_disable(); > spin_lock_irqsave(&mapping->tree_lock, flags); Hmm, but spin_lock_irqsave already implies the disabled preemption. -- Michal Hocko SUSE Labs
