From: Roman Gushchin <guro@xxxxxx> Subject: mm: kmem: enable kernel memcg accounting from interrupt contexts If a memcg to charge can be determined (using remote charging API), there are no reasons to exclude allocations made from an interrupt context from the accounting. Such allocations will pass even if the resulting memcg size will exceed the hard limit, but it will affect the application of the memory pressure and an inability to put the workload under the limit will eventually trigger the OOM. To use active_memcg() helper, memcg_kmem_bypass() is moved back to memcontrol.c. Link: http://lkml.kernel.org/r/20200827225843.1270629-5-guro@xxxxxx Signed-off-by: Roman Gushchin <guro@xxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memcontrol.h | 12 ------------ mm/memcontrol.c | 13 +++++++++++++ 2 files changed, 13 insertions(+), 12 deletions(-) --- a/include/linux/memcontrol.h~mm-kmem-enable-kernel-memcg-accounting-from-interrupt-contexts +++ a/include/linux/memcontrol.h @@ -1531,18 +1531,6 @@ static inline bool memcg_kmem_enabled(vo return static_branch_likely(&memcg_kmem_enabled_key); } -static inline bool memcg_kmem_bypass(void) -{ - if (in_interrupt()) - return true; - - /* Allow remote memcg charging in kthread contexts. */ - if ((!current->mm || (current->flags & PF_KTHREAD)) && - !current->active_memcg) - return true; - return false; -} - static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) { --- a/mm/memcontrol.c~mm-kmem-enable-kernel-memcg-accounting-from-interrupt-contexts +++ a/mm/memcontrol.c @@ -1090,6 +1090,19 @@ static __always_inline struct mem_cgroup return memcg; } +static __always_inline bool memcg_kmem_bypass(void) +{ + /* Allow remote memcg charging from any context. */ + if (unlikely(active_memcg())) + return false; + + /* Memcg to charge can't be determined. */ + if (in_interrupt() || !current->mm || (current->flags & PF_KTHREAD)) + return true; + + return false; +} + /** * If active memcg is set, do not fallback to current->mm->memcg. */ _
