Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-18 Thread Tejun Heo
On Mon, Feb 18, 2013 at 09:16:47AM -0800, Tejun Heo wrote: > On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote: > > commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 ("cgroup: fix lockdep > > warning for event_control") solved a deadlock by introducing a new > > bug. > > > > Move

Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-18 Thread Tejun Heo
On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote: > commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 ("cgroup: fix lockdep > warning for event_control") solved a deadlock by introducing a new > bug. > > Move cgrp->event_list to a temporary list doesn't mean you can traverse > this list

Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-18 Thread Li Zefan
On 2013/2/18 18:36, Kirill A. Shutemov wrote: > On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote: >> commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 ("cgroup: fix lockdep >> warning for event_control") solved a deadlock by introducing a new >> bug. >> >> Move cgrp->event_list to a

Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-18 Thread Kirill A. Shutemov
On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote: > commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 ("cgroup: fix lockdep > warning for event_control") solved a deadlock by introducing a new > bug. > > Move cgrp->event_list to a temporary list doesn't mean you can traverse > this list

Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-18 Thread Kirill A. Shutemov
On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote: commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 (cgroup: fix lockdep warning for event_control) solved a deadlock by introducing a new bug. Move cgrp-event_list to a temporary list doesn't mean you can traverse this list locklessly,

Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-18 Thread Li Zefan
On 2013/2/18 18:36, Kirill A. Shutemov wrote: On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote: commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 (cgroup: fix lockdep warning for event_control) solved a deadlock by introducing a new bug. Move cgrp-event_list to a temporary list doesn't

Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-18 Thread Tejun Heo
On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote: commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 (cgroup: fix lockdep warning for event_control) solved a deadlock by introducing a new bug. Move cgrp-event_list to a temporary list doesn't mean you can traverse this list locklessly,

Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-18 Thread Tejun Heo
On Mon, Feb 18, 2013 at 09:16:47AM -0800, Tejun Heo wrote: On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote: commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 (cgroup: fix lockdep warning for event_control) solved a deadlock by introducing a new bug. Move cgrp-event_list to a

[PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-17 Thread Li Zefan
commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 ("cgroup: fix lockdep warning for event_control") solved a deadlock by introducing a new bug. Move cgrp->event_list to a temporary list doesn't mean you can traverse this list locklessly, because at the same time cgroup_event_wake() can be called

[PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race

2013-02-17 Thread Li Zefan
commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 (cgroup: fix lockdep warning for event_control) solved a deadlock by introducing a new bug. Move cgrp-event_list to a temporary list doesn't mean you can traverse this list locklessly, because at the same time cgroup_event_wake() can be called and