mm: memcontrol: move out cgroup swaprate throttling

The cgroup swaprate throttling is about matching new anon allocations to the rate of available IO when that is being throttled. It's the io controller hooking into the VM, rather than a memory controller thing. Rename mem_cgroup_throttle_swaprate() to cgroup_throttle_swaprate(), and drop the @memcg argument which is only used to check whether the preceding page charge has succeeded and the fault is proceeding. We could decouple the call from mem_cgroup_try_charge() here as well, but that would cause unnecessary churn: the following patches convert all callsites to a new charge API and we'll decouple as we go along. Signed-off-by: Johannes Weiner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Alex Shi <[email protected]> Reviewed-by: Joonsoo Kim <[email protected]> Reviewed-by: Shakeel Butt <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Balbir Singh <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
RoPieee · Jun 4, 2020 · 6caa6a0 · 6caa6a0
1 parent 14235ab
commit 6caa6a0
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Showing 3 changed files with 11 additions and 14 deletions.
diff --git a/include/linux/swap.h b/include/linux/swap.h
@@ -651,11 +651,9 @@ static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
 #endif
 
 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-extern void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg, int node,
-					 gfp_t gfp_mask);
+extern void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask);
 #else
-static inline void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg,
-						int node, gfp_t gfp_mask)
+static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
 {
 }
 #endif

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
@@ -6553,12 +6553,11 @@ int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
 int mem_cgroup_try_charge_delay(struct page *page, struct mm_struct *mm,
 			  gfp_t gfp_mask, struct mem_cgroup **memcgp)
 {
-	struct mem_cgroup *memcg;
 	int ret;
 
 	ret = mem_cgroup_try_charge(page, mm, gfp_mask, memcgp);
-	memcg = *memcgp;
-	mem_cgroup_throttle_swaprate(memcg, page_to_nid(page), gfp_mask);
+	if (*memcgp)
+		cgroup_throttle_swaprate(page, gfp_mask);
 	return ret;
 }
 

diff --git a/mm/swapfile.c b/mm/swapfile.c
@@ -3798,11 +3798,12 @@ static void free_swap_count_continuations(struct swap_info_struct *si)
 }
 
 #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg, int node,
-				  gfp_t gfp_mask)
+void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
 {
 	struct swap_info_struct *si, *next;
-	if (!(gfp_mask & __GFP_IO) || !memcg)
+	int nid = page_to_nid(page);
+
+	if (!(gfp_mask & __GFP_IO))
 		return;
 
 	if (!blk_cgroup_congested())
@@ -3816,11 +3817,10 @@ void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg, int node,
 		return;
 
 	spin_lock(&swap_avail_lock);
-	plist_for_each_entry_safe(si, next, &swap_avail_heads[node],
-				  avail_lists[node]) {
+	plist_for_each_entry_safe(si, next, &swap_avail_heads[nid],
+				  avail_lists[nid]) {
 		if (si->bdev) {
-			blkcg_schedule_throttle(bdev_get_queue(si->bdev),
-						true);
+			blkcg_schedule_throttle(bdev_get_queue(si->bdev), true);
 			break;
 		}
 	}