linux-kernel - [PATCH 0/4] memcg: nmi-safe kmem charging

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250509232859.657525-1-shakeel.butt@linux.dev>
Date: Fri,  9 May 2025 16:28:55 -0700
From: Shakeel Butt <shakeel.butt@...ux.dev>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Johannes Weiner <hannes@...xchg.org>,
	Michal Hocko <mhocko@...nel.org>,
	Roman Gushchin <roman.gushchin@...ux.dev>,
	Muchun Song <muchun.song@...ux.dev>,
	Vlastimil Babka <vbabka@...e.cz>,
	Alexei Starovoitov <ast@...nel.org>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
	bpf@...r.kernel.org,
	linux-mm@...ck.org,
	cgroups@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Meta kernel team <kernel-team@...a.com>
Subject: [PATCH 0/4] memcg: nmi-safe kmem charging

BPF programs can trigger memcg charged kernel allocations in nmi
context. However memcg charging infra for kernel memory is not equipped
to handle nmi context. This series adds support for kernel memory
charging for nmi context.

The initial prototype tried to make memcg charging infra for kernel
memory re-entrant against irq and nmi. However upon realizing that
this_cpu_* operations are not safe on all architectures (Tejun), this
series took a different approach targeting only nmi context. Since the
number of stats that are updated in kernel memory charging path are 3,
this series added special handling of those stats in nmi context rather
than making all >100 memcg stats nmi safe.

There will be a followup series which will make kernel memory charging
reentrant for irq and will be able to do without disabling irqs.

We ran network intensive workload on this series and have not seen any
significant performance differences with and without the series.

Shakeel Butt (4):
  memcg: add infra for nmi safe memcg stats
  memcg: add nmi-safe update for MEMCG_KMEM
  memcg: nmi-safe slab stats updates
  memcg: make objcg charging nmi safe

 include/linux/memcontrol.h |  6 +++
 mm/memcontrol.c            | 87 +++++++++++++++++++++++++++++++++++---
 2 files changed, 88 insertions(+), 5 deletions(-)

-- 
2.47.1