On Mon, Jul 12, 2021 at 12:11 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > On Fri 09-07-21 17:36:24, Suren Baghdasaryan wrote: > > Add mem_cgroup_disabled check in vmpressure, mem_cgroup_uncharge_swap and > > cgroup_throttle_swaprate functions. This minimizes the memcg overhead in > > the pagefault and exit_mmap paths when memcgs are disabled using > > cgroup_disable=memory command-line option. > > This change results in ~2.1% overhead reduction when running PFT test > > What is PFT test? Christoph Lamenter’s pagefault tool (https://lkml.org/lkml/2006/8/29/294). I'll add the link in the description for clarity. > > > comparing {CONFIG_MEMCG=n, CONFIG_MEMCG_SWAP=n} against {CONFIG_MEMCG=y, > > CONFIG_MEMCG_SWAP=y, cgroup_disable=memory} configuration on an 8-core > > ARM64 Android device. > > > > Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx> > > Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > > Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> > > Acked-by: Michal Hocko <mhocko@xxxxxxxx> Thanks! > > Thanks! > > > --- > > mm/memcontrol.c | 3 +++ > > mm/swapfile.c | 3 +++ > > mm/vmpressure.c | 7 ++++++- > > 3 files changed, 12 insertions(+), 1 deletion(-) > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index ae1f5d0cb581..a228cd51c4bd 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -7305,6 +7305,9 @@ void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) > > struct mem_cgroup *memcg; > > unsigned short id; > > > > + if (mem_cgroup_disabled()) > > + return; > > + > > id = swap_cgroup_record(entry, 0, nr_pages); > > rcu_read_lock(); > > memcg = mem_cgroup_from_id(id); > > diff --git a/mm/swapfile.c b/mm/swapfile.c > > index 1e07d1c776f2..707fa0481bb4 100644 > > --- a/mm/swapfile.c > > +++ b/mm/swapfile.c > > @@ -3778,6 +3778,9 @@ void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask) > > struct swap_info_struct *si, *next; > > int nid = page_to_nid(page); > > > > + if (mem_cgroup_disabled()) > > + return; > > + > > if (!(gfp_mask & __GFP_IO)) > > return; > > > > diff --git a/mm/vmpressure.c b/mm/vmpressure.c > > index d69019fc3789..9b172561fded 100644 > > --- a/mm/vmpressure.c > > +++ b/mm/vmpressure.c > > @@ -240,7 +240,12 @@ static void vmpressure_work_fn(struct work_struct *work) > > void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree, > > unsigned long scanned, unsigned long reclaimed) > > { > > - struct vmpressure *vmpr = memcg_to_vmpressure(memcg); > > + struct vmpressure *vmpr; > > + > > + if (mem_cgroup_disabled()) > > + return; > > + > > + vmpr = memcg_to_vmpressure(memcg); > > > > /* > > * Here we only want to account pressure that userland is able to > > -- > > 2.32.0.93.g670b81a890-goog > > -- > Michal Hocko > SUSE Labs
