Re: [patch -mmotm] mm: invoke oom killer for __GFP_NOFAIL

[Jens Axboe <jens.axboe@oracle.com>]

On Tue, May 12 2009, Nick Piggin wrote:
> On Tue, May 12, 2009 at 06:37:30PM +0200, Jens Axboe wrote:
> > On Tue, May 12 2009, Nick Piggin wrote:
> > > On Tue, May 12, 2009 at 02:42:02PM +0200, Jens Axboe wrote:
> > > > On Mon, May 11 2009, Andrew Morton wrote:
> > > > > On Sat, 9 May 2009 15:46:39 -0700 (PDT)
> > > > > David Rientjes <rientjes@google.com> wrote:
> > > > > 
> > > > > > The oom killer must be invoked regardless of the order if the allocation
> > > > > > is __GFP_NOFAIL, otherwise it will loop forever when reclaim fails to
> > > > > > free some memory.
> > > > > 
> > > > > Sigh.  We're supposed to be deleting __GFP_NOFAIL.  I added it as a way
> > > > > of easily finding lame error-handling-challenged callers which need to
> > > > > be fixed up.  So of course we went and added lots more callers.
> > > > > 
> > > > > y:/usr/src/linux-2.6.30-rc5> grep -rl GFP_NOFAIL . 
> > > > > ./fs/bio-integrity.c
> > > 
> > > This is no good either, it seems to be in the bio submission path.
> > > 
> > > It needs a mempool or something.
> > 
> > mempool cannot help here, since the allocation is tied to the process
> > (and IO) life time.
> 
> Oh, I was talking about bio-integrity.c...

Oops my bad, I was on the (apparently) cfq case. I agree on the
integrity path, a mempool should work fine for that.

-- 
Jens Axboe