On Mon 19-11-12 17:44:34, David Rientjes wrote: > While profiling numa/core v16 with cgroup_disable=memory on the command > line, I noticed mem_cgroup_count_vm_event() still showed up as high as > 0.60% in perftop. > > This occurs because the function is called extremely often even when memcg > is disabled. > > To fix this, inline the check for mem_cgroup_disabled() so we avoid the > unnecessary function call if memcg is disabled. > > Signed-off-by: David Rientjes <[email protected]>
Acked-by: Michal Hocko <[email protected]> Thanks! > --- > include/linux/memcontrol.h | 9 ++++++++- > mm/memcontrol.c | 9 ++++----- > 2 files changed, 12 insertions(+), 6 deletions(-) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -181,7 +181,14 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone > *zone, int order, > gfp_t gfp_mask, > unsigned long *total_scanned); > > -void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx); > +void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item > idx); > +static inline void mem_cgroup_count_vm_event(struct mm_struct *mm, > + enum vm_event_item idx) > +{ > + if (mem_cgroup_disabled() || !mm) > + return; > + __mem_cgroup_count_vm_event(mm, idx); > +} > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > void mem_cgroup_split_huge_fixup(struct page *head); > #endif > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -59,6 +59,8 @@ > #include <trace/events/vmscan.h> > > struct cgroup_subsys mem_cgroup_subsys __read_mostly; > +EXPORT_SYMBOL(mem_cgroup_subsys); > + > #define MEM_CGROUP_RECLAIM_RETRIES 5 > static struct mem_cgroup *root_mem_cgroup __read_mostly; > > @@ -1015,13 +1017,10 @@ void mem_cgroup_iter_break(struct mem_cgroup *root, > iter != NULL; \ > iter = mem_cgroup_iter(NULL, iter, NULL)) > > -void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) > +void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item > idx) > { > struct mem_cgroup *memcg; > > - if (!mm) > - return; > - > rcu_read_lock(); > memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); > if (unlikely(!memcg)) > @@ -1040,7 +1039,7 @@ void mem_cgroup_count_vm_event(struct mm_struct *mm, > enum vm_event_item idx) > out: > rcu_read_unlock(); > } > -EXPORT_SYMBOL(mem_cgroup_count_vm_event); > +EXPORT_SYMBOL(__mem_cgroup_count_vm_event); > > /** > * mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg > -- > To unsubscribe from this list: send the line "unsubscribe cgroups" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
