memcg: more mem_cgroup_uncharge() batching

It seems odd that truncate_inode_pages_range(), called not only when
truncating but also when evicting inodes, has mem_cgroup_uncharge_start
and _end() batching in its second loop to clear up a few leftovers, but
not in its first loop that does almost all the work: add them there too.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/truncate.c b/mm/truncate.c
index 49feb46..d64296b 100644 (file)
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -225,6 +225,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
        next = start;
        while (next <= end &&
               pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
+               mem_cgroup_uncharge_start();
                for (i = 0; i < pagevec_count(&pvec); i++) {
                        struct page *page = pvec.pages[i];
                        pgoff_t page_index = page->index;
@@ -247,6 +248,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
                        unlock_page(page);
                }
                pagevec_release(&pvec);
+               mem_cgroup_uncharge_end();
                cond_resched();
        }