On Thu 28-01-21 14:15:31, Andrew Morton wrote: > On Thu, 28 Jan 2021 14:00:29 -0800 Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote: > > > On 1/28/21 1:37 PM, Andrew Morton wrote: > > > On Thu, 28 Jan 2021 06:52:21 +0100 Oscar Salvador <osalvador@xxxxxxx> wrote: > > > > > >> On Wed, Jan 27, 2021 at 03:36:41PM -0800, Mike Kravetz wrote: > > >>> Yes, this patch is somewhat optional. It should be a minor improvement > > >>> in cases where we are dealing with hpages in a non-migratable hstate. > > >>> Although, I do not believe this is the common case. > > >>> > > >>> The real reason for even looking into this was a comment by Oscar. With > > >>> the name change to HPageMigratable, it implies that the page is migratable. > > >>> However, this is not the case if the page's hstate does not support migration. > > >>> So, if we check the hstate when setting the flag we can eliminate those > > >>> cases where the page is certainly not migratable. > > >>> > > >>> I don't really love this patch. It has minimal functional value. > > >>> > > >>> Oscar, what do you think about dropping this? > > >> > > >> Yeah, I remember this topic arose during a discussion of patch#2 in the > > >> early versions, about whether the renaming to HPageMigratable made > > >> sense. > > >> > > >> Back then I thought that we could have this in one place at fault-path [1], > > >> which should have made this prettier, but it is not the case. > > >> True is that the optimization is little, so I am fine with dropping this > > >> patch. > > > > > > I've dropped it. > > > > Thanks Andrew. > > > > Michal suggested that comments describing synchronization be added for each > > flag. Since I did 'one patch per flag', that would be an update to each patch. > > Or, I could simply add a patch to update the comment block based on what you > > already have. > > > > Let me know what is best/easiest for you. > > I guess just one patch is best for reviewers. Then I'll split up into > a sprinkle of -fix patches if I'm feeling energetic ;) A single patch on top should be just fine. It is not like this would be a bisectability breaker. -- Michal Hocko SUSE Labs