memcg: never OOM when charging huge pages
Huge page coverage should obviously have less priority than the continued
execution of a process.
Never kill a process when charging it a huge page fails. Instead, give up
after the first failed reclaim attempt and fall back to regular pages.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: 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/memcontrol.c b/mm/memcontrol.c
index 0e81eb5..fc75f34 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2351,13 +2351,19 @@
gfp_t gfp_mask, enum charge_type ctype)
{
struct mem_cgroup *mem = NULL;
- struct page_cgroup *pc;
- int ret;
int page_size = PAGE_SIZE;
+ struct page_cgroup *pc;
+ bool oom = true;
+ int ret;
if (PageTransHuge(page)) {
page_size <<= compound_order(page);
VM_BUG_ON(!PageTransHuge(page));
+ /*
+ * Never OOM-kill a process for a huge page. The
+ * fault handler will fall back to regular pages.
+ */
+ oom = false;
}
pc = lookup_page_cgroup(page);
@@ -2366,7 +2372,7 @@
return 0;
prefetchw(pc);
- ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page_size);
+ ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, oom, page_size);
if (ret || !mem)
return ret;
