Re: [PATCH v3 3/5] zsmalloc: Add a LRU to zs_pool to keep track of zspages in LRU order

From: Minchan Kim
Date: Wed Nov 16 2022 - 18:49:40 EST


On Wed, Nov 16, 2022 at 05:02:57PM -0500, Johannes Weiner wrote:
> On Thu, Nov 10, 2022 at 02:48:32PM -0800, Minchan Kim wrote:
> > On Thu, Nov 10, 2022 at 09:18:31AM -0800, Nhat Pham wrote:
> > > > Please put the LRU logic under config ZSMALLOC_LRU since we don't need the
> > > > additional logic to others.
> > >
> > > I think the existing CONFIG_ZPOOL would be a good option for this purpose. It
> > > should disable the LRU behavior for non-zswap use case (zram for e.g). The
> > > eviction logic is also currently defined under this. What do you think,
> > > Minchan?
> >
> > That sounds good.
> >
> > Sergey and I are working to change zsmalloc zspage size.
> > https://lore.kernel.org/linux-mm/20221031054108.541190-1-senozhatsky@xxxxxxxxxxxx/
> >
> > Could you send a new version once we settle those change down
> > in Andrew's tree to minimize conflict?
> > (Feel free to join the review/discussion if you are also interested ;-))
>
> I've been reading through that thread, and it doesn't look like it'll
> be ready for the upcoming merge window. (I've tried to contribute

Depending on the discussion status :)

> something useful to it, but it's a fairly difficult tuning problem,
> and I don't know if a sysfs knob is the best answer, either...)

That's the point.

>
> Would you have any objections to putting Nhat's patches here into 6.2?

I don't want to block due to other issues so no objection from my side.

>
> It doesn't sound like there was any more feedback (except the trivial
> ifdef around the LRU), and the patches are otherwise ready to go.

In fact, I didn't start the review yet so please post it unless
Sergey objects it.

Thank you.