Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1268420

[PATCH 03/14] net: tcp_memcontrol: properly detect ancestor socket pressure

Show all headers | View raw

When charging socket memory, the code currently checks only the local
page counter for excess to determine whether the memcg is under socket
pressure. But even if the local counter is fine, one of the ancestors
could have breached its limit, which should also force this child to
enter socket pressure. This currently doesn't happen.

Fix this by using page_counter_try_charge() first. If that fails, it
means that either the local counter or one of the ancestors are in
excess of their limit, and the child should enter socket pressure.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
 include/net/sock.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index bbf7c2c..c4b33c9 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1190,11 +1190,13 @@ static inline void memcg_memory_allocated_add(struct cg_proto *prot,
 					      unsigned long amt,
 					      int *parent_status)
 {
-	page_counter_charge(&prot->memory_allocated, amt);
+	struct page_counter *counter;
+
+	if (page_counter_try_charge(&prot->memory_allocated, amt, &counter))
+		return;
 
-	if (page_counter_read(&prot->memory_allocated) >
-	    prot->memory_allocated.limit)
-		*parent_status = OVER_LIMIT;
+	page_counter_charge(&prot->memory_allocated, amt);
+	*parent_status = OVER_LIMIT;
 }
 
 static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
-- 
2.6.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 00/14] mm: memcontrol: account socket memory in unified hierarchy Johannes Weiner <hannes@cmpxchg.org> - 2015-11-13 00:50 +0100
  [PATCH 03/14] net: tcp_memcontrol: properly detect ancestor socket pressure Johannes Weiner <hannes@cmpxchg.org> - 2015-11-13 00:50 +0100
    Re: [PATCH 03/14] net: tcp_memcontrol: properly detect ancestor  socket pressure David Miller <davem@davemloft.net> - 2015-11-13 17:10 +0100
    Re: [PATCH 03/14] net: tcp_memcontrol: properly detect ancestor  socket pressure Vladimir Davydov <vdavydov@virtuozzo.com> - 2015-11-14 13:50 +0100
      Re: [PATCH 03/14] net: tcp_memcontrol: properly detect ancestor  socket pressure Johannes Weiner <hannes@cmpxchg.org> - 2015-11-14 16:20 +0100
  [PATCH 09/14] net: tcp_memcontrol: simplify linkage between socket and page counter Johannes Weiner <hannes@cmpxchg.org> - 2015-11-13 00:50 +0100
  [PATCH 01/14] mm: memcontrol: export root_mem_cgroup Johannes Weiner <hannes@cmpxchg.org> - 2015-11-13 00:50 +0100
    Re: [PATCH 01/14] mm: memcontrol: export root_mem_cgroup David Miller <davem@davemloft.net> - 2015-11-13 17:00 +0100
    Re: [PATCH 01/14] mm: memcontrol: export root_mem_cgroup Vladimir Davydov <vdavydov@virtuozzo.com> - 2015-11-14 13:20 +0100
  [PATCH 10/14] mm: memcontrol: generalize the socket accounting jump label Johannes Weiner <hannes@cmpxchg.org> - 2015-11-13 00:50 +0100
    Re: [PATCH 10/14] mm: memcontrol: generalize the socket accounting  jump label Michal Hocko <mhocko@kernel.org> - 2015-11-13 11:50 +0100
    Re: [PATCH 10/14] mm: memcontrol: generalize the socket accounting  jump label Vladimir Davydov <vdavydov@virtuozzo.com> - 2015-11-14 14:40 +0100

csiph-web