On Sun, Aug 23, 2026 at 10:02:35AM +0300, Mike Rapoport wrote:
> Hi Eric,
>
> On Fri, Aug 21, 2026 at 02:56:52PM -0400, Eric Chanudet wrote:
> > CMA allocations are currently unaccounted for by cgroup memory
> > controllers. As system resources, they should fall under memcg, but CMA
> > areas partition the available space for different purposes and memcg
> > doesn't have a good representation for that.
> >
> > Add a memory_cma_accounting cgroupfs option in preparation for the
> > following new behavior. Make it disabled by default since it will
> > account for CMA allocations in memcg which may affect existing systems.
> >
> > Provide CMA charge/uncharge functions to memcg that introduce a CMA area
> > specific counter per CMA area. Charges are issued to memcg and to a page
> > counter for the CMA area used. The allocation's folios are marked with
> > the cgroup via commit_charge() (once for large folios, per-page for
> > 0-order ones) so they can be later uncharged correctly.
> >
> > Add the new memcg calls into the cma allocator under __cma_alloc_frozen,
> > for both cma and hugetlb_cma allocations accounting.
> >
> > Finally register the per-area usage counters in the cgroupfs. Each CMA
> > area creates a memory.cma.<area>.{current,max} pair for reporting and
> > limitation for each area.
> >
> > Selftests and a vmtest script are added to this series for convenience.
> > The tests are simple accounting and limit enforcement verification using
> > the default reserved CMA area (cma=) and hugetlb_cma.
> >
> > Signed-off-by: Eric Chanudet <[email protected]>
> > ---
> > Eric Chanudet (11):
> > mm/cma: drop const for struct page on release API
> > mm/cma: include linux/cma.h in cma.h
> > cgroup: add memory_cma_accounting mount option
> > memcg: add cma charge/uncharge functions for area counters
> > mm/cma: charge cma allocation to memcg per area counters
> > memcg: register per-area usage counters in cgroupfs
> > selftests: cgroup: add cma configs for cgroup selftest suite
> > selftests: cgroup: add memcg cma tests
> > selftests: cgroup: add a vmtest script for memcg
> > selftests: cgroup: add memcg hugetlb_cma tests
> > selftests: cgroup: amend vmtest-memcg to run the hugetlb cma tests
>
> CI found issues:
>
> https://github.com/linux-mm/linux-mm/actions/runs/32519133924
Indeed my apologies, I messed up CMA=n it needed a forward declaration
and gating for mm/cma.h content included in mm/memcontrol.c.
I queued this up for a v2, with the other issues reported by Sashiko.
>
> > Documentation/admin-guide/cgroup-v2.rst | 35 +++
> > include/linux/cgroup-defs.h | 5 +
> > include/linux/cma.h | 4 +-
> > include/linux/memcontrol.h | 19 ++
> > kernel/cgroup/cgroup.c | 15 +-
> > mm/cma.c | 14 +-
> > mm/cma.h | 6 +
> > mm/cma_debug.c | 1 -
> > mm/cma_sysfs.c | 1 -
> > mm/memcontrol.c | 205 ++++++++++++
> > tools/testing/selftests/cgroup/.gitignore | 1 +
> > tools/testing/selftests/cgroup/Makefile | 2 +
> > tools/testing/selftests/cgroup/config | 5 +
> > tools/testing/selftests/cgroup/test_cma_memcg.c | 402
> > ++++++++++++++++++++++++
> > tools/testing/selftests/cgroup/vmtest-memcg.sh | 197 ++++++++++++
> > 15 files changed, 903 insertions(+), 9 deletions(-)
> > ---
> > base-commit: 98f21c54f99519329c18e2625b0ea6db14524d09
> > change-id: 20260706-cma-memcg-regions-696cb5ef7998
> >
> > Best regards,
> > --
> > Eric Chanudet <[email protected]>
> >
>
> --
> Sincerely yours,
> Mike.
>
--
Eric Chanudet
