Messages in this thread | | | Date | Sun, 14 Sep 2008 23:36:17 +0200 | From | Nick Piggin <> | Subject | Re: [lockdep] possible circular locking, between &mm->mmap_sem and &dev->ev_mutex |
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On Sun, Sep 14, 2008 at 12:44:42AM -0700, Andrew Morton wrote: > On Sun, 14 Sep 2008 09:39:06 +0200 Ingo Molnar <mingo@elte.hu> wrote: > > > with the new mmap_sem lockdep annotations, -tip testing found a third > > lockdep assert, see below. Config attached. > > > > Ingo > > > > -----------------> > > [ 6460.634452] > > [ 6460.634465] ======================================================= > > [ 6460.634494] [ INFO: possible circular locking dependency detected ] > > [ 6460.634517] 2.6.27-rc6-tip-00290-g8e229c3-dirty #1 > > [ 6460.634535] ------------------------------------------------------- > > [ 6460.634555] gdm-simple-gree/4778 is trying to acquire lock: > > [ 6460.634574] (&mm->mmap_sem){----}, at: [<c018fe33>] might_fault+0x36/0x73 > > [ 6460.634639] > > [ 6460.634645] but task is already holding lock: > > [ 6460.634662] (&dev->ev_mutex){--..}, at: [<c01c7a76>] inotify_read+0xd8/0x16e > > [ 6460.634715] > > [ 6460.634721] which lock already depends on the new lock. > > Yes, there's a thread in my intray called "inotify_read's ev_mutex vs > do_page_fault's mmap_sem...". It's a bit flakey-looking, but there's a > patch in there.
This is the first one I fixed up, I think? What's flakey about it? I sent 2 versions, and the first had an obvious bug but the second worked for me and reporter...
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