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author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2009-07-29 15:04:06 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-07-29 19:10:35 -0700 |
commit | 887032670d47366a8c8f25396ea7c14b7b2cc620 (patch) | |
tree | e5f9ece5ab9239648e8d7051ccb9a217d92553d7 /mm/page_alloc.c | |
parent | f0d83679a8d471dc8b646919f70595d6fe8c9606 (diff) |
cgroup avoid permanent sleep at rmdir
After commit ec64f51545fffbc4cb968f0cea56341a4b07e85a ("cgroup: fix
frequent -EBUSY at rmdir"), cgroup's rmdir (especially against memcg)
doesn't return -EBUSY by temporary ref counts. That commit expects all
refs after pre_destroy() is temporary but...it wasn't. Then, rmdir can
wait permanently. This patch tries to fix that and change followings.
- set CGRP_WAIT_ON_RMDIR flag before pre_destroy().
- clear CGRP_WAIT_ON_RMDIR flag when the subsys finds racy case.
if there are sleeping ones, wakes them up.
- rmdir() sleeps only when CGRP_WAIT_ON_RMDIR flag is set.
Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Paul Menage <menage@google.com>
Acked-by: Balbir Sigh <balbir@linux.vnet.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
0 files changed, 0 insertions, 0 deletions