lkml.org 
[lkml]   [2009]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: lockdep warning with 2.6.29-rc6-mm1 (mmotm 24-feb-2009)
On Wed, Mar 04, 2009 at 06:41:15PM +0100, Ingo Molnar wrote:
>
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Wed, 2009-03-04 at 18:27 +0530, Balbir Singh wrote:
> > > I see the following on my machine. My understanding is that the
> > > lockdep warning is complaining about a potential deadlock while
> > > reclaiming, where we could end up waiting on holding inotify_mutex,
> > > and we could end up calling reclaim with inotify_mutex held.
> > >
> > > The race seems rare, since one path shows a new inode being created
> > > and the other one being deleted. It seems like a false positive unless
> > > the inode's in question turn out to be potentially the same.
> >
> > Its not a false positive until you can guarantee the inodes will _never_
> > be the same.
> >
> > This thing has been reported numerous times, Ingo even posted
> > a potential fix for it, Nick poked the inotify people to speak
> > up, but they have so far been silent on the issue :-(
>
> that particular fix is upstream, via:
>
> 3023a3e: inotify: fix GFP_KERNEL related deadlock
>
> so does this reproduce with latest .29-rc7-ish kernels too - or
> do we have some other problem in this area too?

Well as I said, I think it is just a bandaid to shut up lockdep,
because I think inotify always is guaranteed to have a ref on
the inode at this point so it should not be subject to reclaim.



\
 
 \ /
  Last update: 2009-03-05 08:03    [W:0.069 / U:1.464 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site