From: Ralph Campbell <rcampbell@nvidia.com>
To: Alistair Popple <apopple@nvidia.com>
Cc: linux-mm@kvack.org, Felix Kuehling <felix.kuehling@amd.com>,
Philip Yang <Philip.Yang@amd.com>,
Jason Gunthorpe <jgg@nvidia.com>,
Andrew Morton <akpm@linux-foundation.org>,
stable@vger.kernel.org
Subject: Re: [PATCH] mm/hmm: fault non-owner device private entries
Date: Mon, 25 Jul 2022 10:56:18 -0700 [thread overview]
Message-ID: <afd72eec-1a91-7985-db2b-d2dd0516e819@nvidia.com> (raw)
In-Reply-To: <878rohbkeg.fsf@nvdebian.thelocal>
On 7/25/22 02:32, Alistair Popple wrote:
> Ralph Campbell <rcampbell@nvidia.com> writes:
>
>> If hmm_range_fault() is called with the HMM_PFN_REQ_FAULT flag and a
>> device private PTE is found, the hmm_range::dev_private_owner page is
>> used to determine if the device private page should not be faulted in.
>> However, if the device private page is not owned by the caller,
>> hmm_range_fault() returns an error instead of calling migrate_to_ram()
>> to fault in the page.
> /*
> * Never fault in device private pages, but just report
> * the PFN even if not present.
> */
>
> This comment needs updating because it will be possible to fault in
> device private pages now.
>
> It also looks a bit strange to be checking for device private entries
> twice - I think it would be clearer if hmm_is_device_private_entry() is
> removed and the ownership check done directly in hmm_vma_handle_pte().
>
> - Alistair
I'll fix this in v2. Thanks for the review.
next prev parent reply other threads:[~2022-07-25 17:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-22 22:56 Ralph Campbell
2022-07-23 13:32 ` Jason Gunthorpe
2022-07-25 17:54 ` Ralph Campbell
2022-07-25 9:32 ` Alistair Popple
2022-07-25 17:56 ` Ralph Campbell [this message]
2022-07-25 14:08 ` Felix Kuehling
2022-07-25 18:49 ` Andrew Morton
2022-07-25 19:07 ` Ralph Campbell
2022-07-25 22:29 ` Andrew Morton
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