From: Alistair Popple <apopple@nvidia.com>
To: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
Ralph Campbell <rcampbell@nvidia.com>,
nouveau@lists.freedesktop.org, stable@vger.kernel.org
Subject: Re: [PATCH] mm: Take a page reference when removing device exclusive entries
Date: Thu, 30 Mar 2023 11:26:04 +1100 [thread overview]
Message-ID: <87zg7vt75v.fsf@nvidia.com> (raw)
In-Reply-To: <bbc8bc42-5f2a-9238-94e9-b2191e2f8c7e@nvidia.com>
John Hubbard <jhubbard@nvidia.com> writes:
> On 3/28/23 20:16, Matthew Wilcox wrote:
> ...
>>> + if (!get_page_unless_zero(vmf->page))
>>> + return 0;
>> From a folio point of view: what the hell are you doing here? Tail
>> pages don't have individual refcounts; all the refcounts are actually
I had stuck with using the page because none of this stuff (yet)
supports compound pages anyway so we shouldn't see a tail page
anyway. But point taken, I admit I need to find some time to get a
deeper internalised understanding of folios than just s/page/folio.
> ohh, and I really should have caught that too. I plead spending too much
> time recently in a somewhat more driver-centric mindset, and failing to
> mentally shift gears properly for this case.
>
> Sorry for missing that!
>
> thanks,
next prev parent reply other threads:[~2023-03-30 0:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-28 2:14 [PATCH] mm: Take a page reference when removing device exclusive entries Alistair Popple
2023-03-28 6:25 ` John Hubbard
2023-03-28 19:55 ` Andrew Morton
2023-03-29 1:45 ` Alistair Popple
2023-03-28 19:59 ` Ralph Campbell
2023-03-29 3:16 ` Matthew Wilcox
2023-03-29 3:45 ` John Hubbard
2023-03-30 0:26 ` Alistair Popple [this message]
2023-03-30 0:55 ` Alistair Popple
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