Re: [PATCH] iommu/amd: Take mmap_sem when calling get_user_pages

[Suravee Suthikulanit]

On 5/6/2014 2:11 PM, Suravee Suthikulanit wrote:
> On 5/6/2014 1:14 PM, Joerg Roedel wrote:
> > On Mon, Apr 28, 2014 at 05:27:46PM -0500, Suthikulpanit, Suravee wrote:
> > > From: Jay Cornwall <jay.cornwall@xxxxxxx>
> > >
> > > get_user_pages requires caller to hold a read lock on mmap_sem.
> >
> > Right, but can't we just switch to get_user_pages_fast instead?
> >
> >
> >     Joerg
>
> You're right. I think it can. Let me spin out another patch.
>
> Suravee

Actually, we would have to provide the pointer to task_struct for the 
corresponding PASID which is not necessary "current".  So I take it 
back. I don't think we can use _fast.

Suravee
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