Re: [PATCH] mm/swapfile.c: select the swap device with default priority round robin

[Baoquan He <bhe@redhat.com>]

On 09/24/25 at 09:06am, Chris Li wrote:
> On Wed, Sep 24, 2025 at 8:54 AM Chris Li <chrisl@kernel.org> wrote:
> >
> > Hi Baoquan,
> >
> > Very exciting numbers. I have always suspected the per node priority
> > is not doing much contribution in the new swap allocator world. I did
> > not expect it to have negative contributions.
> >
> > On Wed, Sep 24, 2025 at 2:18 AM Baoquan He <bhe@redhat.com> wrote:
> > >
> > > Currently, on system with multiple swap devices, swap allocation will
> > > select one swap device according to priority. The swap device with the
> > > highest priority will be chosen to allocate firstly.
> > >
> > > People can specify a priority from 0 to 32767 when swapon a swap device,
> > > or the system will set it from -2 then downwards by default. Meanwhile,
> > > on NUMA system, the swap device with node_id will be considered first
> > > on that NUMA node of the node_id.
> >
> > That behavior was introduced by: a2468cc9bfdf ("swap: choose swap
> > device according to numa node")
> 
> BTW, I noticed you did not CC Aaron Lu who introduced  a2468cc9bfdf. I
> CC him here and give him a chance to test it in his environment to
> defend his patch. Please CC him on the next version if his email does
> not bounce.

Sure, definitely we should CC Aaron. Thanks a lot for noticing.