On Tue, Oct 29, 2024 at 08:34:34AM +0800, Huang, Ying wrote: > Gregory Price <gourry@xxxxxxxxxx> writes: > > > On Mon, Oct 28, 2024 at 01:45:48PM -0700, Yang Shi wrote: > >> On Fri, Oct 25, 2024 at 7:17 AM Gregory Price <gourry@xxxxxxxxxx> wrote: > >> > > >> > This path happens for SUCCESSFUL migrations, not failures. Typically > >> > callers to migrate_pages are required to handle putback/accounting for > >> > failures, but this is already handled in the shrink code. > >> > >> AFAIK, MGLRU doesn't dec/inc this counter, so it is not > >> double-decrement for MGLRU. Maybe "imbalance update" is better? > >> Anyway, it is just a nit. I'd suggest capturing the MGLRU case in the > >> commit log too. > >> > > > > Gotcha, so yeah saying it's an imbalance fix is more accurate. > > > > So more accurate changelog is: ... > > I think that it may be better to mention the different behavior of LRU > and MGLRU. But that's not a big deal, change it again only if you think > it's necessary. > The behavior isn't really different. It's either way migrate_pages decrements when it shouldn't going through the shink code - and both LRU and MGLRU go through the same code. That LRU does an inc/dec pair is irrelevant - neither should do the decrement in the migrate path. ~Gregory