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author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2010-05-11 14:06:58 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-11 17:33:42 -0700 |
commit | 7f0f15464185a92f9d8791ad231bcd7bf6df54e4 (patch) | |
tree | a1d4f4c39632659497963b0ccf62828237478d72 /firmware/dsp56k | |
parent | 11cad320a4f4bc53d3585c85600c782faa12b99e (diff) |
memcg: fix css_id() RCU locking for real
Commit ad4ba375373937817404fd92239ef4cadbded23b ("memcg: css_id() must be
called under rcu_read_lock()") modifies memcontol.c for fixing RCU check
message. But Andrew Morton pointed out that the fix doesn't seems sane
and it was just for hidining lockdep messages.
This is a patch for do proper things. Checking again, all places,
accessing without rcu_read_lock, that commit fixies was intentional....
all callers of css_id() has reference count on it. So, it's not necessary
to be under rcu_read_lock().
Considering again, we can use rcu_dereference_check for css_id(). We know
css->id is valid if css->refcnt > 0. (css->id never changes and freed
after css->refcnt going to be 0.)
This patch makes use of rcu_dereference_check() in css_id/depth and remove
unnecessary rcu-read-lock added by the commit.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'firmware/dsp56k')
0 files changed, 0 insertions, 0 deletions