From 56cab2859fbe08e1f2a5ac3f4655dcc398bc013d Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Thu, 2 Sep 2021 14:54:47 -0700 Subject: [PATCH] mm, memcg: add mem_cgroup_disabled checks in vmpressure and swap-related functions 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 [1] 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. [1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite Link: https://lkml.kernel.org/r/20210713010934.299876-1-surenb@google.com Signed-off-by: Suren Baghdasaryan Reviewed-by: Shakeel Butt Reviewed-by: Muchun Song Acked-by: Johannes Weiner Acked-by: Michal Hocko Cc: Alex Shi Cc: Alistair Popple Cc: David Hildenbrand Cc: Jens Axboe Cc: Joonsoo Kim Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Minchan Kim Cc: Roman Gushchin Cc: Tejun Heo Cc: Wei Yang Cc: Yang Shi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 1047f02..211f391 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -7297,6 +7297,9 @@ 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 7527afd..627b16a 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3784,6 +3784,9 @@ 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 d69019f..9b17256 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 -- 2.7.4