On Wed, 21 Feb 2007, Andrew Morton wrote:
> On Wed, 21 Feb 2007 16:22:17 -0500 (EST)
> Alan Stern <[EMAIL PROTECTED]> wrote:
>
> > On Wed, 21 Feb 2007, Andrew Morton wrote:
> >
> > > > > It seems like usb-storage and aio are completely off in the weeds.
> > > > > Ideas?
> > > >
> > > > It seems usb-storage should remove some kmalloc and use mempool() for
> > > > urb... Is someone working on this? And idea?
> > >
> > > I think Pete said that we're supposed to be using GFP_NOIO in there.
> >
> > We _are_ using it.
>
> How admirably prompt.
Shucks, we've been using it for years...
> > > Not that it'll help much: the VM calls throttle_vm_writeout() for GFP_NOIO
> > > and GFP_NOFS allocations, which is a bug. Because if the caller holds
> > > locks which prevent filesystem or IO progress, we deadlock.
> > >
> > > I'll fix the VM if someone else fixes USB ;)
> >
> > What else needs to be fixed?
>
> Would be nice if someone can confirm that this fixes it:
Not having experienced the problem, I can't confirm the fix. However...
> + if ((gfp_mask & (__GFP_FS|__GFP_IO)) != (__GFP_FS|__GFP_IO)) {
Is that really the correct test? I don't know enough about the memory
management subsystem to say one way or the other. What's special about
having both flags set?
> + /*
> + * The caller might hold locks which can prevert IO completion
--------------------------------------------------------------^ Typo
Although perhaps "prevert" is an acceptable neologism in this context.
> + * or progress in the filesystem. So we cannot just sit here
> + * waiting for IO to complete.
> + */
Alan Stern
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