Re: [PATCH 2/7] mmc: Don't use PF_MEMALLOC

From: Oliver Neukum
Date: Tue Nov 17 2009 - 05:38:12 EST


Am Dienstag, 17. November 2009 11:32:36 schrieb Minchan Kim:
> On Tue, Nov 17, 2009 at 7:29 PM, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Tue, 17 Nov 2009 16:17:50 +0900 (JST)
> >
> > KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote:
> >> Non MM subsystem must not use PF_MEMALLOC. Memory reclaim need few
> >> memory, anyone must not prevent it. Otherwise the system cause
> >> mysterious hang-up and/or OOM Killer invokation.
> >
> > So now what happens if we are paging and all our memory is tied up for
> > writeback to a device or CIFS etc which can no longer allocate the memory
> > to complete the write out so the MM can reclaim ?
> >
> > Am I missing something or is this patch set not addressing the case where
> > the writeback thread needs to inherit PF_MEMALLOC somehow (at least for
> > the I/O in question and those blocking it)
>
> I agree.
> At least, drivers for writeout is proper for using PF_MEMALLOC, I think.

For the same reason error handling should also use it, shouldn't it?

Regards
Oliver
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