]> www.infradead.org Git - users/jedix/linux-maple.git/commit
memcg: memcg_rstat_updated re-entrant safe against irqs
authorShakeel Butt <shakeel.butt@linux.dev>
Wed, 14 May 2025 18:41:52 +0000 (11:41 -0700)
committerAndrew Morton <akpm@linux-foundation.org>
Thu, 22 May 2025 21:55:38 +0000 (14:55 -0700)
commit8a4b42b955286c122c4402b458acbc1d92953fbd
tree6f775a9f2d2f8b345814facd8e99c6a030fb5ebe
parentcc79061b8fc119807111b615aa791562374b15b2
memcg: memcg_rstat_updated re-entrant safe against irqs

Patch series "memcg: make memcg stats irq safe", v2.

This series converts memcg stats to be irq safe i.e.  memcg stats can be
updated in any context (task, softirq or hardirq) without disabling the
irqs.  This is still not nmi-safe on all architectures but after this
series converting memcg charging and stats nmi-safe will be easier.

This patch (of 7):

memcg_rstat_updated() is used to track the memcg stats updates for
optimizing the flushes.  At the moment, it is not re-entrant safe and the
callers disabled irqs before calling.  However to achieve the goal of
updating memcg stats without irqs, memcg_rstat_updated() needs to be
re-entrant safe against irqs.

This patch makes memcg_rstat_updated() re-entrant safe using this_cpu_*
ops.  On archs with CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS, this patch is
also making memcg_rstat_updated() nmi safe.

[lorenzo.stoakes@oracle.com: fix build]
Link: https://lkml.kernel.org/r/22f69e6e-7908-4e92-96ca-5c70d535c439@lucifer.local
Link: https://lkml.kernel.org/r/20250514184158.3471331-1-shakeel.butt@linux.dev
Link: https://lkml.kernel.org/r/20250514184158.3471331-2-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/memcontrol.c