Re: [PATCH v3] mm: page_alloc: make defrag_mode retries follow the promoted order

[Kiryl Shutsemau]

On Thu, Oct 15, 2026 at 03:53:30PM +0200, Vlastimil Babka (SUSE) wrote:
> On 10/15/26 14:55, Kiryl Shutsemau wrote:
> > On Thu, Oct 15, 2026 at 09:16:36AM +0200, Vlastimil Babka (SUSE) wrote:
> >> > And agree 7.4-rc1 with CC stable is fine. Sadly, not sure if anyone
> >> > but Meta is using the feature right now.
> >> 
> >> I thought it was there for a long time but it was only added in 2025 :) At
> >> least the enterprise world is slow to adopt things, AFAICS.
> > 
> > I was thinking to propose a patch after merge window to make defrag_mode
> > default. Do you think it is too early? I don't think it is ever going
> > to be truly stabilized without wider exposure.
> 
> We can try it, but preferably with arguments (and best, numbers).

Will do.

> > We also discussed with Johannes to make a stricter (defrag_mode=2?) mode
> > that will not give up on fragmentation ever, but OOM instead.
> 
> Would you use that mode at Meta? That however most likely wouldn't be
> general purpose enough to become default.

Yes, we consider it to be preferable to fragmentation. But it requires
experimentation.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov