memcg: simplify page cache charging (dc67d504) · Commits · 戴 / test

This patch is a clean up. No functional/logical changes. Because of commit ("mm: add replace_page_cache_page() function") , FUSE uses replace_page_cache() instead of add_to_page_cache(). Then, mem_cgroup_cache_charge() is not called against FUSE's pages from splice. So now, mem_cgroup_cache_charge() gets pages that are not on the LRU with the exception of PageSwapCache pages. For checking, WARN_ON_ONCE(PageLRU(page)) is added. Signed-off-by:

KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Miklos Szeredi <mszeredi@suse.cz> Acked-by:

Michal Hocko <mhocko@suse.cz> Acked-by:

Johannes Weiner <hannes@cmpxchg.org> Cc: Ying Han <yinghan@google.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

+9 −22

Original line number	Diff line number	Diff line
		@@ -2790,6 +2790,7 @@ int mem_cgroup_cache_charge(struct page page, struct mm_struct mm,
		gfp_t gfp_mask)
		{
		struct mem_cgroup *memcg = NULL;
		enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
		int ret;

		if (mem_cgroup_disabled())
		@@ -2799,31 +2800,17 @@ int mem_cgroup_cache_charge(struct page page, struct mm_struct mm,

		if (unlikely(!mm))
		mm = &init_mm;
		if (!page_is_file_cache(page))
		type = MEM_CGROUP_CHARGE_TYPE_SHMEM;

		if (page_is_file_cache(page)) {
		ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, &memcg, true);
		if (ret \|\| !memcg)
		return ret;

		/*
		* FUSE reuses pages without going through the final
		* put that would remove them from the LRU list, make
		* sure that they get relinked properly.
		*/
		__mem_cgroup_commit_charge_lrucare(page, memcg,
		MEM_CGROUP_CHARGE_TYPE_CACHE);
		return ret;
		}
		/* shmem */
		if (PageSwapCache(page)) {
		if (!PageSwapCache(page)) {
		ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
		WARN_ON_ONCE(PageLRU(page));
		} else { /* page is swapcache/shmem */
		ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &memcg);
		if (!ret)
		__mem_cgroup_commit_charge_swapin(page, memcg,
		MEM_CGROUP_CHARGE_TYPE_SHMEM);
		} else
		ret = mem_cgroup_charge_common(page, mm, gfp_mask,
		MEM_CGROUP_CHARGE_TYPE_SHMEM);

		__mem_cgroup_commit_charge_swapin(page, memcg, type);
		}
		return ret;
		}

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