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From: "Brendan Jackman" To: "Petr Tesarik" , "Brendan Jackman" Cc: "Andrew Morton" , "David Hildenbrand" , "Lorenzo Stoakes" , "Liam R. Howlett" , "Vlastimil Babka" , "Mike Rapoport" , "Suren Baghdasaryan" , "Michal Hocko" , , "Brendan Jackman" , "Johannes Weiner" , "Zi Yan" , References: <20260612085052.59291-1-ptesarik@suse.com> <20260612133155.71958e80@mordecai> In-Reply-To: <20260612133155.71958e80@mordecai> X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 7752320011 X-Stat-Signature: z66nqciansynwprnkgkt7x3kpb738cb1 X-Rspam-User: X-HE-Tag: 1781274525-141702 X-HE-Meta: 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 1P3q2zpa KtC2qcXhypW9db2QJemQT9RL4mMmjvq/7FRc/FL06sEUz1l0P8SQV6Oy8T5VeQ65x8q7fFD5yxXc12xAaJd92mvmJHSsUa7kXHXV/W4A1f1lwJ6oG0znW5kZMguSUdTgd7P/hrY9PU1t62vbJ+TtBmX0nPARQmcKKfb66Zq9FTDqMOyrtCFgK7pUyC4AQN64S2HmulCZaERh+DGZvxWu24KIa1OIrbaHqYWJ7wArM2JKrB0rlhdBz+TW0mi8qECu38f6H5Y+lul0MzovWW3SeMsIjY8wRvhzLiBcF Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri Jun 12, 2026 at 11:31 AM UTC, Petr Tesarik wrote: >> > >> > - NODE_RECLAIM_NOSCAN -> NODE_RECLAIM_NONE >> > - NODE_RECLAIM_FULL -> NODE_RECLAIM_NONE >> > - NODE_RECLAIM_SOME -> NODE_RECLAIM_SUCCESS >> > - NODE_RECLAIM_SUCCESS -> NODE_RECLAIM_SUCCESS >> > --- a/mm/internal.h >> > +++ b/mm/internal.h >> > @@ -1373,23 +1373,24 @@ static inline void mminit_verify_zonelist(void= ) >> > } >> > #endif /* CONFIG_DEBUG_MEMORY_INIT */ >> > =20 >> > -#define NODE_RECLAIM_NOSCAN -2 >> > -#define NODE_RECLAIM_FULL -1 >> > -#define NODE_RECLAIM_SOME 0 >> > -#define NODE_RECLAIM_SUCCESS 1 >> > +enum node_reclaim { >> > + NODE_RECLAIM_NONE, >> > + NODE_RECLAIM_SUCCESS, >> > +}; >> > - ret =3D __node_reclaim(pgdat, gfp_mask, nr_pages, &sc) >=3D nr_pages= ; >> > + nr_reclaimed =3D __node_reclaim(pgdat, gfp_mask, nr_pages, &sc); >> > clear_bit_unlock(PGDAT_RECLAIM_LOCKED, &pgdat->flags); >> > =20 >> > - if (ret) >> > + if (nr_reclaimed >=3D nr_pages) >> > count_vm_event(PGSCAN_ZONE_RECLAIM_SUCCESS); >> > else >> > count_vm_event(PGSCAN_ZONE_RECLAIM_FAILED); >> > =20 >> > - return ret; >> > + return NODE_RECLAIM_SUCCESS; =20 >>=20 >> Should that be returning NODE_RECLAIM_NONE when !ret? > > No. That's the thing. Before my patch, the return value here was either > NODE_RECLAIM_SUCCESS (when at least nr_pages were reclaimed), or > NODE_RECLAIM_SOME (if less than nr_pages were reclaimed), but the caller > makes no distinction, handling both cases in the default label of a > switch statement. Agh! Sorry. It's good that you are cleaning this up :D So in that case my question is: is it intended that we call zone_watermark_ok() in the case that we reclaimed 0 pages? If not, maybe what we want here is: - One patch to stop doing that. - Another patch to switch over to the enum. And then it _would_ return NODE_RECLAIM_NONE when !ret? Have a weird feeling I'm still being stupid here, let's see...