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Subject: Re: [BUG] infinite loop in find_get_pages()
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Hugh Dickins <hughd@google.com>
Cc: Shaohua Li <shaohua.li@intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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Date: Thu, 15 Sep 2011 00:08:09 +0200
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Le mercredi 14 septembre 2011 à 14:53 -0700, Hugh Dickins a écrit :
> On Wed, 14 Sep 2011, Eric Dumazet wrote:
> > Le mercredi 14 septembre 2011 à 13:38 -0700, Hugh Dickins a écrit :
> > > 
> > > I'd like to think about that a little more before finalizing the
> > > patch below - does it work, and does it look acceptable so far?
> > > Of course, the mods to truncate.c and vmscan.c are not essential
> > > parts of this fix, just things to tidy up while on the subject.
> > > Right now I must attend to some other stuff, will return tomorrow.
> > 
> > Hello Hugh
> > 
> > I am going to test this ASAP,
> 
> Thanks, Eric, though it may not be worth spending your time on it.
> It occurred to me over lunch that it may take painfully longer than
> expected to invalidate_mapping_pages() on a single-swapped-out-page
> 1TB sparse tmpfs file - all those "start += 1" restarts until it
> reaches the end.
> 
> I might decide to leave invalidate_mapping_pages() giving up early
> (unsatisfying, but no worse than before), and convert scan_mapping_
> unevictable_pages() (which is used on nothing but shmem) to pass
> index vector to radix_tree_gang_whatever().
> 
> Dunno, I'll think about it more later.
> 

I tested your patch as is on my machine, and everything seems fine.

I let the stress continue while I am going to sleep :)

See you