On 17.08.20 18:05, Alexander Duyck wrote: > > > On 8/17/2020 2:35 AM, David Hildenbrand wrote: >> On 17.08.20 10:48, Wei Yang wrote: >>> If "page" is the list head, list_for_each_entry_safe() would stop >>> iteration. >>> >>> Signed-off-by: Wei Yang <richard.weiy...@linux.alibaba.com> >>> --- >>> mm/page_reporting.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/mm/page_reporting.c b/mm/page_reporting.c >>> index 3bbd471cfc81..aaaa3605123d 100644 >>> --- a/mm/page_reporting.c >>> +++ b/mm/page_reporting.c >>> @@ -178,7 +178,7 @@ page_reporting_cycle(struct page_reporting_dev_info >>> *prdev, struct zone *zone, >>> * the new head of the free list before we release the >>> * zone lock. >>> */ >>> - if (&page->lru != list && !list_is_first(&page->lru, list)) >>> + if (!list_is_first(&page->lru, list)) >>> list_rotate_to_front(&page->lru, list); >>> >>> /* release lock before waiting on report processing */ >>> >> >> Is this a fix or a cleanup? If it's a fix, can this be reproduced easily >> and what ere the effects? >> > > This should be a clean-up. Since the &page->lru != list will always be true. >
Makes sense, maybe we can make that a little bit clearer in the patch description. > If I recall at some point the that was a check for &next->lru != list > but I think I pulled out an additional conditional check somewhere so > that we just go through the start of the loop again and iterate over > reported pages until we are guaranteed to have a non-reported page to > rotate to the top of the list with the general idea being that we wanted > the allocator to pull non-reported pages before reported pages. -- Thanks, David / dhildenb
