Re: [PATCH 4/9] mm, page_alloc: simplify pageset_update()

2020-10-05 Thread Michal Hocko
On Tue 22-09-20 16:37:07, Vlastimil Babka wrote: > pageset_update() attempts to update pcplist's high and batch values in a way > that readers don't observe batch > high. It uses smp_wmb() to order the > updates > in a way to achieve this. However, without proper pairing read barriers in >

Re: [PATCH 4/9] mm, page_alloc: simplify pageset_update()

2020-09-25 Thread David Hildenbrand
On 22.09.20 16:37, Vlastimil Babka wrote: > pageset_update() attempts to update pcplist's high and batch values in a way > that readers don't observe batch > high. It uses smp_wmb() to order the > updates > in a way to achieve this. However, without proper pairing read barriers in > readers this

[PATCH 4/9] mm, page_alloc: simplify pageset_update()

2020-09-22 Thread Vlastimil Babka
pageset_update() attempts to update pcplist's high and batch values in a way that readers don't observe batch > high. It uses smp_wmb() to order the updates in a way to achieve this. However, without proper pairing read barriers in readers this guarantee doesn't hold, and there are no such