Re: [PATCH v12 10/14] x86/sgx: Charge mem_cgroup for per-cgroup reclamation

Huang, Kai
2024-04-23T07:21:52Z

On Mon, 2024-04-15 at 20:20 -0700, Haitao Huang wrote:
> Enclave Page Cache(EPC) memory can be swapped out to regular system
> memory, and the consumed memory should be charged to a proper
> mem_cgroup. Currently the selection of mem_cgroup to charge is done in
> sgx_encl_get_mem_cgroup(). But it considers all contexts other than the
> ksgxd thread are user processes. With the new EPC cgroup implementation,
> the swapping can also happen in EPC cgroup work-queue threads. In those
> cases, it improperly selects the root mem_cgroup to charge for the RAM
> usage.
>
> Remove current_is_ksgxd() and change sgx_encl_get_mem_cgroup() to take
> an additional argument to explicitly specify the mm struct to charge for
> allocations. Callers from background kthreads not associated with a
> charging mm struct would set it to NULL, while callers in user process
> contexts set it to current->mm.
>
> Internally, it handles the case when the charging mm given is NULL, by
> searching for an mm struct from enclave's mm_list.
>
> Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
> Reported-by: Mikko Ylinen <mikko.ylinen@linux.intel.com>
> Tested-by: Mikko Ylinen <mikko.ylinen@linux.intel.com>
> Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
>

Reviewed-by: Kai Huang <kai.huang@intel.com>