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  • [parent not found: <AANLkTino0k-wok9kXLmWTyr40dZKSCnR0Uk41uxAj5k1@mail.gmail.com>]
    • * [PATCH] cgroup: alloc_css_id() increments hierarchy depth
@ 2010-05-28 15:16 Greg Thelen
  0 siblings, 0 replies; 8+ messages in thread
From: Greg Thelen @ 2010-05-28 15:16 UTC (permalink / raw)
  To: Paul Menage, Paul E. McKenney, Li Zefan
  Cc: Ben Blum, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA, Andrew Morton

Child groups should have a greater depth than their parents.
Prior to this change, the parent would incorrectly report zero
memory usage for child cgroups when use_hierarchy is enabled.

test script:
  mount -t cgroup none /cgroups -o memory
  cd /cgroups
  mkdir cg1

  echo 1 > cg1/memory.use_hierarchy
  mkdir cg1/cg11

  echo $$ > cg1/cg11/tasks
  dd if=/dev/zero of=/tmp/foo bs=1M count=1

  echo
  echo CHILD
  grep cache cg1/cg11/memory.stat

  echo
  echo PARENT
  grep cache cg1/memory.stat

  echo $$ > tasks
  rmdir cg1/cg11 cg1
  cd /
  umount /cgroups

Using fae9c79, a recent patch that changed alloc_css_id() depth computation,
the parent incorrectly reports zero usage:
  root@ubuntu:~# ./test
  1+0 records in
  1+0 records out
  1048576 bytes (1.0 MB) copied, 0.0151844 s, 69.1 MB/s

  CHILD
  cache 1048576
  total_cache 1048576

  PARENT
  cache 0
  total_cache 0

With this patch, the parent correctly includes child usage:
  root@ubuntu:~# ./test
  1+0 records in
  1+0 records out
  1048576 bytes (1.0 MB) copied, 0.0136827 s, 76.6 MB/s

  CHILD
  cache 1052672
  total_cache 1052672

  PARENT
  cache 0
  total_cache 1052672

Signed-off-by: Greg Thelen <gthelen-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
---
 kernel/cgroup.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 422cb19..3ac6f5b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4598,7 +4598,7 @@ static int alloc_css_id(struct cgroup_subsys *ss, struct cgroup *parent,
 	parent_css = parent->subsys[subsys_id];
 	child_css = child->subsys[subsys_id];
 	parent_id = parent_css->id;
-	depth = parent_id->depth;
+	depth = parent_id->depth + 1;
 
 	child_id = get_new_cssid(ss, depth);
 	if (IS_ERR(child_id))
-- 
1.7.0.1

^ permalink raw reply related	[flat|nested] 8+ messages in thread
    end of thread, other threads:[~2010-05-31  1:01 UTC | newest]

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2010-05-28 22:25   ` [PATCH] cgroup: alloc_css_id() increments hierarchy depth Paul Menage
     [not found] ` <AANLkTino0k-wok9kXLmWTyr40dZKSCnR0Uk41uxAj5k1@mail.gmail.com>
     [not found]   ` <AANLkTino0k-wok9kXLmWTyr40dZKSCnR0Uk41uxAj5k1-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-05-30 23:45     ` KAMEZAWA Hiroyuki
     [not found]   ` <20100531084529.2b1f0d25.kamezawa.hiroyu@jp.fujitsu.com>
     [not found]     ` <20100531085431.a45b30b9.kamezawa.hiroyu@jp.fujitsu.com>
     [not found]       ` <20100531085431.a45b30b9.kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2010-05-31  0:44         ` Greg Thelen
     [not found]       ` <AANLkTilNrrsNluDBUlXCsZMz7d_-VHn31Ogvkw9AUPnE@mail.gmail.com>
     [not found]         ` <AANLkTilNrrsNluDBUlXCsZMz7d_-VHn31Ogvkw9AUPnE-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-05-31  0:43           ` KAMEZAWA Hiroyuki
2010-05-31  1:01           ` Li Zefan
     [not found]     ` <20100531084529.2b1f0d25.kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2010-05-30 23:54       ` KAMEZAWA Hiroyuki
2010-05-31  0:59       ` Li Zefan
2010-05-28 15:16 Greg Thelen

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