On Fri, May 22, 2026 at 08:53:10AM -0700, Shakeel Butt wrote: > On Tue, May 19, 2026 at 11:59:01AM -0400, Eric Chanudet wrote: > > Add mem_cgroup_dmem_charge() and mem_cgroup_dmem_uncharge() to allow > > dmem pool allocations to optionally be double-charged against the memory > > controller. Take the struct cgroup from the dmem pool's css as there is > > no convenient object exported to represent these allocations. These will > > resolve the effective memory css from that cgroup and perform the > > charge. > > > > Introduce a MEMCG_DMEM stat counter to memory.stat to make the cgroup's > > dmem charge visible. > > > > Signed-off-by: Eric Chanudet <[email protected]> > > --- > > include/linux/memcontrol.h | 16 ++++++++++++ > > mm/memcontrol.c | 65 > > ++++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 81 insertions(+) > > > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > > index > > dc3fa687759b45748b2acee6d7f43da325eb50c1..8e1d49b87fb64e6114f3eb920293e14920290fe7 > > 100644 > > --- a/include/linux/memcontrol.h > > +++ b/include/linux/memcontrol.h > > @@ -39,6 +39,7 @@ enum memcg_stat_item { > > MEMCG_ZSWAP_B, > > MEMCG_ZSWAPPED, > > MEMCG_ZSWAP_INCOMP, > > + MEMCG_DMEM, > > MEMCG_NR_STAT, > > }; > > > > @@ -1872,6 +1873,21 @@ static inline bool > > mem_cgroup_zswap_writeback_enabled(struct mem_cgroup *memcg) > > } > > #endif > > > > +#if defined(CONFIG_MEMCG) && defined(CONFIG_CGROUP_DMEM) > > +bool mem_cgroup_dmem_charge(struct cgroup *cgrp, unsigned int nr_pages, > > + gfp_t gfp_mask); > > +void mem_cgroup_dmem_uncharge(struct cgroup *cgrp, unsigned int nr_pages); > > +#else > > +static inline bool mem_cgroup_dmem_charge(struct cgroup *cgrp, > > + unsigned int nr_pages, gfp_t gfp_mask) > > Please follow Johannes's request to pass the actually memory object instead of > naked numbers. >
Also what exactly is the backing memory here? Is it system memory? If yes, then you need to pass struct page. For non-system memory, I am not sure memcg is the right place to charge such memory.
