On Mon, Aug 17, 2020 at 07:07:04PM +0200, David Hildenbrand wrote: >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.weiyang@xxxxxxxxxxxxxxxxx> >>>> --- >>>> 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. > Ok, do you have some suggestion on the description? A clean-up for commit xxx? I would appreciate your suggestion :-) >> 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 -- Wei Yang Help you, Help me
