From: Jason Gunthorpe <jgg@mellanox.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jerome Glisse <jglisse@redhat.com>,
Ralph Campbell <rcampbell@nvidia.com>,
Felix.Kuehling@amd.com, linux-mm@kvack.org,
John Hubbard <jhubbard@nvidia.com>,
dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org,
Philip Yang <Philip.Yang@amd.com>
Subject: Re: [PATCH hmm 8/8] mm/hmm: add missing call to hmm_pte_need_fault in HMM_PFN_SPECIAL handling
Date: Mon, 16 Mar 2020 10:04:58 -0300 [thread overview]
Message-ID: <20200316130458.GQ13183@mellanox.com> (raw)
In-Reply-To: <20200316124953.GC17386@lst.de>
On Mon, Mar 16, 2020 at 01:49:53PM +0100, Christoph Hellwig wrote:
> On Mon, Mar 16, 2020 at 09:10:53AM -0300, Jason Gunthorpe wrote:
> > On Mon, Mar 16, 2020 at 10:13:47AM +0100, Christoph Hellwig wrote:
> > > On Wed, Mar 11, 2020 at 03:35:06PM -0300, Jason Gunthorpe wrote:
> > > > From: Jason Gunthorpe <jgg@mellanox.com>
> > > >
> > > > Currently if a special PTE is encountered hmm_range_fault() immediately
> > > > returns EFAULT and sets the HMM_PFN_SPECIAL error output (which nothing
> > > > uses).
> > > >
> > > > EFAULT should only be returned after testing with hmm_pte_need_fault().
> > > >
> > > > Also pte_devmap() and pte_special() are exclusive, and there is no need to
> > > > check IS_ENABLED, pte_special() is stubbed out to return false on
> > > > unsupported architectures.
> > >
> > > I think the right fix is to just kill HMM_PFN_SPECIAL and treat any
> > > fault on special ptes that aren't the zero page as an error.
> >
> > I have another series that is doing that - this change is to make the
> > next series make sense and not introduce new control logic too.
>
> Ok. I had some cleanups like this based of older trees, but if you are
> active in this area I think I'll let you handle it.
You once said you wanted to loose the weird pfn flags scheme, so
before putting hmm_range_fault in ODP I planned to do that.
If you have your series someplace send me a URL and I'll look on it
Thanks,
Jason
next prev parent reply other threads:[~2020-03-16 13:05 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 18:34 [PATCH hmm 0/8] Various error case bug fixes for hmm_range_fault() Jason Gunthorpe
2020-03-11 18:34 ` [PATCH hmm 1/8] mm/hmm: add missing unmaps of the ptep during hmm_vma_handle_pte() Jason Gunthorpe
2020-03-12 1:28 ` Ralph Campbell
2020-03-12 14:24 ` Jason Gunthorpe
2020-03-16 8:58 ` Christoph Hellwig
2020-03-11 18:35 ` [PATCH hmm 2/8] mm/hmm: don't free the cached pgmap while scanning Jason Gunthorpe
2020-03-12 1:29 ` Ralph Campbell
2020-03-16 9:02 ` Christoph Hellwig
2020-03-16 18:07 ` Jason Gunthorpe
2020-03-16 18:13 ` Christoph Hellwig
2020-03-16 19:23 ` Jason Gunthorpe
2020-03-11 18:35 ` [PATCH hmm 3/8] mm/hmm: do not call hmm_vma_walk_hole() while holding a spinlock Jason Gunthorpe
2020-03-12 1:31 ` Ralph Campbell
2020-03-12 8:54 ` Steven Price
2020-03-12 10:28 ` [PATCH] mm/hmm: Simplify hmm_vma_walk_pud slightly Steven Price
2020-03-12 14:27 ` Jason Gunthorpe
2020-03-12 14:40 ` Steven Price
2020-03-12 15:11 ` Jason Gunthorpe
2020-03-12 16:16 ` Steven Price
2020-03-12 16:37 ` Jason Gunthorpe
2020-03-12 17:02 ` Steven Price
2020-03-12 17:17 ` Jason Gunthorpe
2020-03-13 19:55 ` Jason Gunthorpe
2020-03-13 21:04 ` Matthew Wilcox
2020-03-13 22:51 ` Jason Gunthorpe
2020-03-16 9:05 ` [PATCH hmm 3/8] mm/hmm: do not call hmm_vma_walk_hole() while holding a spinlock Christoph Hellwig
2020-03-16 12:56 ` Jason Gunthorpe
2020-03-11 18:35 ` [PATCH hmm 4/8] mm/hmm: add missing pfns set to hmm_vma_walk_pmd() Jason Gunthorpe
2020-03-12 1:33 ` Ralph Campbell
2020-03-16 9:06 ` Christoph Hellwig
2020-03-11 18:35 ` [PATCH hmm 5/8] mm/hmm: add missing call to hmm_range_need_fault() before returning EFAULT Jason Gunthorpe
2020-03-12 1:34 ` Ralph Campbell
2020-03-16 9:07 ` Christoph Hellwig
2020-03-11 18:35 ` [PATCH hmm 6/8] mm/hmm: reorganize how !pte_present is handled in hmm_vma_handle_pte() Jason Gunthorpe
2020-03-12 1:36 ` Ralph Campbell
2020-03-16 9:11 ` Christoph Hellwig
2020-03-11 18:35 ` [PATCH hmm 7/8] mm/hmm: return -EFAULT when setting HMM_PFN_ERROR on requested valid pages Jason Gunthorpe
2020-03-12 1:36 ` Ralph Campbell
2020-03-12 14:35 ` Jason Gunthorpe
2020-03-16 9:12 ` Christoph Hellwig
2020-03-11 18:35 ` [PATCH hmm 8/8] mm/hmm: add missing call to hmm_pte_need_fault in HMM_PFN_SPECIAL handling Jason Gunthorpe
2020-03-12 1:38 ` Ralph Campbell
2020-03-16 9:13 ` Christoph Hellwig
2020-03-16 12:10 ` Jason Gunthorpe
2020-03-16 12:49 ` Christoph Hellwig
2020-03-16 13:04 ` Jason Gunthorpe [this message]
2020-03-16 13:12 ` Christoph Hellwig
2020-03-17 12:32 ` Christoph Hellwig
2020-03-17 12:53 ` Jason Gunthorpe
2020-03-17 13:06 ` Christoph Hellwig
2020-03-17 13:25 ` Jason Gunthorpe
2020-03-16 12:51 ` Christoph Hellwig
2020-03-12 19:33 ` [PATCH hmm 9/8] mm/hmm: do not check pmd_protnone twice in hmm_vma_handle_pmd() Jason Gunthorpe
2020-03-12 23:50 ` Ralph Campbell
2020-03-16 9:14 ` Christoph Hellwig
2020-03-16 18:25 ` [PATCH hmm 0/8] Various error case bug fixes for hmm_range_fault() Jason Gunthorpe
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