Messages in this thread | | | Subject | Re: [RFC 3/4] mm, page_alloc: move cpuset seqcount checking to slowpath | From | Vlastimil Babka <> | Date | Wed, 18 Jan 2017 10:48:55 +0100 |
| |
On 01/18/2017 10:40 AM, Michal Hocko wrote: > On Tue 17-01-17 23:16:09, Vlastimil Babka wrote: >> This is a preparation for the following patch to make review simpler. While >> the primary motivation is a bug fix, this could also save some cycles in the >> fast path. > > I cannot say I would be happy about this patch :/ The code is still very > confusing and subtle. I really think we should get rid of > synchronization with the concurrent cpuset/mempolicy updates instead. > Have you considered that instead?
Not so thoroughly yet, but I already suspect it would be intrusive for stable. We could make copies of nodemask and mems_allowed and protect just the copying with seqcount, but that would mean overhead and stack space. Also we might try revert 682a3385e773 ("mm, page_alloc: inline the fast path of the zonelist iterator") ...
| |