Re: [PATCH 0/3] mm,thp,rmap: rework the use of subpages_mapcount

From: Johannes Weiner
Date: Fri Nov 18 2022 - 15:42:16 EST


On Fri, Nov 18, 2022 at 12:18:42PM -0800, Linus Torvalds wrote:
> On Fri, Nov 18, 2022 at 1:08 AM Hugh Dickins <hughd@xxxxxxxxxx> wrote:
> >
> > Linus was underwhelmed by the earlier compound mapcounts series:
> > this series builds on top of it (as in next-20221117) to follow
> > up on his suggestions - except rmap.c still using lock_page_memcg(),
> > since I hesitate to steal the pleasure of deletion from Johannes.
>
> This looks good to me. Particularly 2/3 made me go "Aww, yes" but the
> overall line removal stats look good too.
>
> That said, I only looked at the patches, and not the end result
> itself. But not having the bit spin lock is, I think, a huge
> improvement.
>
> I do wonder if this should be now just merged with your previous
> series - it looks a bit odd how your previous series adds that
> bitlock, only for it to be immediately removed.
>
> But if you think the logic ends up being easier to follow this way as
> two separate patch series, I guess I don't care.
>
> And the memcg locking is entirely a separate issue, and I hope
> Johannes will deal with that.

Yeah, I'll redo the removal on top of this series and resend it.

Thanks