• Kefeng Wang's avatar
    mm: memory: move mem_cgroup_charge() into alloc_anon_folio() · 085ff35e
    Kefeng Wang authored
    The GFP flags from vma_thp_gfp_mask() according to user configuration only
    used for large folio allocation but not for memory cgroup charge, and
    GFP_KERNEL is used for both order-0 and large order folio when memory
    cgroup charge at present.  However, mem_cgroup_charge() uses the GFP flags
    in a fairly sophisticated way.  In addition to checking
    gfpflags_allow_blocking(), it pays attention to __GFP_NORETRY and
    __GFP_RETRY_MAYFAIL to ensure that processes within this memcg do not
    exceed their quotas.
    
    So we'd better to move mem_cgroup_charge() into alloc_anon_folio(),
    
    1) it will make us to allocate as much as possible large order folio,
       because we could try the next order if mem_cgroup_charge() fails,
       although the memcg's memory usage is close to its limits.
    
    2) using same GFP flags for allocation and charge is to be consistent
       with PMD THP firstly, in addition, according to GFP flag returned from
       vma_thp_gfp_mask(), GFP_TRANSHUGE_LIGHT could make us skip direct
       reclaim, _GFP_NORETRY will make us skip mem_cgroup_oom() and won't
       trigger memory cgroup oom from large order(order <= COSTLY_ORDER) folio
       charging.
    
    Link: https://lkml.kernel.org/r/20240122011612.501029-1-wangkefeng.wang@huawei.com
    Link: https://lkml.kernel.org/r/20240117103954.2756050-1-wangkefeng.wang@huawei.comSigned-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
    Reviewed-by: default avatarRyan Roberts <ryan.roberts@arm.com>
    Cc: David Hildenbrand <david@redhat.com>
    Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
    Cc: Michal Hocko <mhocko@suse.com>
    Cc: Roman Gushchin <roman.gushchin@linux.dev>
    Cc: Johannes Weiner <hannes@cmpxchg.org>
    Cc: Shakeel Butt <shakeelb@google.com>
    Cc: Muchun Song <songmuchun@bytedance.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    085ff35e
memory.c 171 KB