Re: [PATCH] zsmalloc: do not use bit_spin_lock

From: Vitaly Wool
Date: Thu Jan 14 2021 - 12:16:27 EST


On Thu, Jan 14, 2021 at 5:56 PM Sebastian Andrzej Siewior
<bigeasy@xxxxxxxxxxxxx> wrote:
>
> On 2021-01-14 17:29:37 [+0100], Vitaly Wool wrote:
> > On Thu, 14 Jan 2021, 17:18 Sebastian Andrzej Siewior,
> > <bigeasy@xxxxxxxxxxxxx> wrote:
> > >
> > > On 2020-12-23 19:25:02 [+0100], Vitaly Wool wrote:
> > > > > write the following patch according to your idea, what do you think ?
> > > >
> > > > Yep, that is basically what I was thinking of. Some nitpicks below:
> > >
> > > Did this go somewhere? The thread just ends here on my end.
> > > Mike, is this patch fixing / helping your case in anyway?
> >
> > Please see
> > * https://marc.info/?l=linux-mm&m=160889419514019&w=2
> > * https://marc.info/?l=linux-mm&m=160889418114011&w=2
> > * https://marc.info/?l=linux-mm&m=160889448814057&w=2
>
> Thank you, that would be
> 1608894171-54174-1-git-send-email-tiantao6@xxxxxxxxxxxxx
>
> for b4 compatibility :)
>
> > Haven't had time to test these yet but seem to be alright.
>
> So zs_map_object() still disables preemption but the mutex part is
> avoided by the patch?

Basically, yes. Minchan was very clear that he didn't want to remove
that inter-function locking, so be it.
I wouldn't really advise to use zsmalloc with zswap because zsmalloc
has no support for reclaim, nevertheless I wouldn't like this
configuration to stop working for those who are already using it.

Would you or Mike be up for testing Tian Taos's patchset?

Best regards,
Vitaly