Re: [PATCH v3 1/1] mm: let node_reclaim() return the number of pages reclaimed

[Johannes Weiner <hannes@cmpxchg.org>]

On Fri, Jul 10, 2026 at 05:23:20PM +0200, Petr Tesarik wrote:
> There is only one caller, get_page_from_freelist(), and it does not make
> any use of the reason for skipping the reclaim, nor does it make any
> distinction between a full and partially successful reclaim.
> 
> Therefore, node_reclaim() can simply return the number of pages that have
> been reclaimed, same as __node_reclaim(), and the NODE_RECLAIM_xxx macros
> can be removed.
> 
> There is one small change of behavior when __node_reclaim() was attempted
> but returned zero. The allocation now skips the zone immediately; before
> this patch, the zone watermarks were checked first. I believe it was an
> oversight rather than intention, because the chances that zone watermark is
> OK after __node_reclaim() did not reclaim any pages are very close to zero.
> 
> Originally, I was looking for occurences of NODE_RECLAIM_SOME and
> NODE_RECLAIM_SUCCESS, but I couldn't find any. That's because they are
> typecast from the result of a relational operator. This seemed a bit
> fragile, so I dug a bit deeper and came up with this proposed cleanup.
> 
> Signed-off-by: Petr Tesarik <ptesarik@suse.com>

Looks good to me, and agree with the minor change in behavior being
acceptable. With the macros actually removed,

Acked-by: Johannes Weiner <hannes@cmpxchg.org>