Re: [PATCH v11] mm/page_alloc: boost watermarks on atomic allocation failure

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 20 Jul 2026 16:15:48 +0800 Qiliang Yuan <realwujing@gmail.com> wrote:

> Atomic allocations (GFP_ATOMIC) are prone to failure under heavy memory
> pressure as they cannot enter direct reclaim.
> 
> Handle these failures by introducing a watermark boost mechanism for
> atomic requests. Refactor boost_watermark() using an internal helper to
> support both fragmentation and atomic paths. Apply zone-proportional
> boosts (~0.1% of managed pages) for atomic allocations, while
> decoupling it from watermark_boost_factor.

Thanks for persisting with this.

You didn't retain Vlastimil's Reviewed-by: from v8?

This is very much a networking thing - they must have considered
similar things.  But my not-very-energetic attempts to get input from
networking people have thus far failed.

> This failure signature keeps recurring in production: a host running
> a downstream 4.19 kernel logged 144 order-0 GFP_ATOMIC failures over a
> 4h15m window, all through the same NIC driver receive softirq path,
> across several unrelated network-facing services on the box. This
> confirms the underlying problem is real and ongoing. It does not by
> itself measure this patch's effect, since the fix has not been
> deployed on that fleet yet.

We'll of course be very interested in these results.  Do you know
if/when they'll be available?

Anyway, let me get this into mm.git and linux-next so we can at least
parallelize wider testing with ongoing review.