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Date: Thu, 17 Jul 2025 15:52:46 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Davidlohr Bueso <dave@stgolabs.net>, mhocko@kernel.org,
 hannes@cmpxchg.org, roman.gushchin@linux.dev, yosryahmed@google.com,
 linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/4] mm/memcg: make memory.reclaim interface generic
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On Thu, 17 Jul 2025 15:17:09 -0700 Shakeel Butt <shakeel.butt@linux.dev> wrote:

> On Mon, Jun 23, 2025 at 11:58:49AM -0700, Davidlohr Bueso wrote:
> > +
> > +int user_proactive_reclaim(char *buf, struct mem_cgroup *memcg, pg_data_t *pgdat)
> > +{
> > +	unsigned int nr_retries = MAX_RECLAIM_RETRIES;
> > +	unsigned long nr_to_reclaim, nr_reclaimed = 0;
> > +	int swappiness = -1;
> > +	char *old_buf, *start;
> > +	substring_t args[MAX_OPT_ARGS];
> > +
> > +	if (!buf || (!memcg && !pgdat))
> 
> I don't think this series is adding a use-case where both memcg and
> pgdat are non-NULL, so let's error out on that as well.

As a followup, please.  This has been in -next for four weeks and I'd
prefer not to have to route around it (again).