[RFC PATCH 0/3] cgroup: nmi safe css_rstat_updated

[Shakeel Butt <shakeel.butt@linux.dev>]

BPF programs can run in nmi context and may trigger memcg charged memory
allocation in such context. Recently linux added support to nmi safe
page allocation along with memcg charging of such allocations. However
the kmalloc/slab support and corresponding memcg charging is still
lacking,

To provide nmi safe support for memcg charging for kmalloc/slab
allocations, we need nmi safe memcg stats and for that we need nmi safe
css_rstat_updated() which adds the given cgroup state whose stats are
updated into the per-cpu per-ss update tree. This series took the aim to
make css_rstat_updated() nmi safe.

This series is based on [1].

[1] http://lore.kernel.org/20250404011050.121777-1-inwardvessel@gmail.com

Shakeel Butt (3):
  llist: add list_add_iff_not_on_list()
  cgroup: support to enable nmi-safe css_rstat_updated
  cgroup: make css_rstat_updated nmi safe

 include/linux/cgroup-defs.h |   4 ++
 include/linux/llist.h       |   3 +
 kernel/cgroup/rstat.c       | 112 ++++++++++++++++++++++++++++--------
 lib/llist.c                 |  30 ++++++++++
 4 files changed, 124 insertions(+), 25 deletions(-)

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2.47.1