mm, memcg: inline swap-related functions to improve disabled memcg config

Inline mem_cgroup_try_charge_swap, mem_cgroup_uncharge_swap and
cgroup_throttle_swaprate functions to perform mem_cgroup_disabled static
key check inline before calling the main body of the function.  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 ~1% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=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/20210713010934.299876-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 6f5a43251593c8a554041fe5ce603df774267041..f30d26b0f71db1b08bb0db6b7704e63f0c8a665b 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -721,7 +721,13 @@ static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
 #endif
 
 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-extern void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask);
+extern void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask);
+static inline  void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
+{
+       if (mem_cgroup_disabled())
+               return;
+       __cgroup_throttle_swaprate(page, gfp_mask);
+}
 #else
 static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
 {
@@ -730,8 +736,22 @@ static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
 
 #ifdef CONFIG_MEMCG_SWAP
 extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry);
-extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);
-extern void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);
+extern int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);
+static inline int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
+{
+       if (mem_cgroup_disabled())
+               return 0;
+       return __mem_cgroup_try_charge_swap(page, entry);
+}
+
+extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);
+static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
+{
+       if (mem_cgroup_disabled())
+               return;
+       __mem_cgroup_uncharge_swap(entry, nr_pages);
+}
+
 extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
 extern bool mem_cgroup_swap_full(struct page *page);
 #else

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 33bb8434eea05badac6c40e10a8fb2dacf0bc0e1..81e15a67391b2a6f927e81c04f064dfc589c42c9 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -7226,7 +7226,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
 }
 
 /**
- * mem_cgroup_try_charge_swap - try charging swap space for a page
+ * __mem_cgroup_try_charge_swap - try charging swap space for a page
  * @page: page being added to swap
  * @entry: swap entry to charge
  *
@@ -7234,16 +7234,13 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
  *
  * Returns 0 on success, -ENOMEM on failure.
  */
-int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
+int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
 {
        unsigned int nr_pages = thp_nr_pages(page);
        struct page_counter *counter;
        struct mem_cgroup *memcg;
        unsigned short oldid;
 
-       if (mem_cgroup_disabled())
-               return 0;
-
        if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
                return 0;
 
@@ -7279,18 +7276,15 @@ int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
 }
 
 /**
- * mem_cgroup_uncharge_swap - uncharge swap space
+ * __mem_cgroup_uncharge_swap - uncharge swap space
  * @entry: swap entry to uncharge
  * @nr_pages: the amount of swap space to uncharge
  */
-void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
+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 627b16aed1dc89974b3be54cfe67e38094f5cd50..22d10f7138487434a56bb37216b1fc868882212e 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3779,14 +3779,11 @@ static void free_swap_count_continuations(struct swap_info_struct *si)
 }
 
 #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
+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;