From: Alistair Popple <apopple@nvidia.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: <linux-mm@kvack.org>, <nouveau@lists.freedesktop.org>,
<bskeggs@redhat.com>, <akpm@linux-foundation.org>,
<linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<dri-devel@lists.freedesktop.org>, <jhubbard@nvidia.com>,
<rcampbell@nvidia.com>, <jglisse@redhat.com>, <hch@infradead.org>,
<daniel@ffwll.ch>
Subject: Re: [PATCH v3 1/8] mm: Remove special swap entry functions
Date: Tue, 2 Mar 2021 11:21:35 +1100 [thread overview]
Message-ID: <3156280.dJpzq75PnV@nvdebian> (raw)
In-Reply-To: <20210301174642.GP4247@nvidia.com>
On Tuesday, 2 March 2021 4:46:42 AM AEDT Jason Gunthorpe wrote:
>
> I wish you could come up with a more descriptive word that special
> here
>
> What I understand is this is true when the swap_offset is a pfn?
Correct, and that points to a better name. Maybe is_pfn_swap_entry()? In which
case adding a helper as Christoph suggested makes some more sense. Eg:
pfn_swap_entry_to_page()
> > -static inline struct page *migration_entry_to_page(swp_entry_t entry)
> > -{
> > - struct page *p = pfn_to_page(swp_offset(entry));
> > - /*
> > - * Any use of migration entries may only occur while the
> > - * corresponding page is locked
> > - */
> > - BUG_ON(!PageLocked(compound_head(p)));
> > - return p;
>
> And this constraint has been completely lost?
Yes, sorry I should have called that out. I didn't think loosing the check was
a big deal, but I can add some checks to some of the call sites which would
catch a page being incorrectly unlocked.
> A comment in front of the is_special_entry explaining all the rule
> would help alot
Will add one.
> Transformation looks fine otherwise
Thanks.
- Alistair
> Jason
>
next prev parent reply other threads:[~2021-03-02 0:21 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-26 7:18 [PATCH v3 0/8] Add support for SVM atomics in Nouveau Alistair Popple
2021-02-26 7:18 ` [PATCH v3 1/8] mm: Remove special swap entry functions Alistair Popple
2021-02-26 15:59 ` Christoph Hellwig
2021-03-02 8:52 ` Alistair Popple
2021-03-01 17:46 ` Jason Gunthorpe
2021-03-02 0:21 ` Alistair Popple [this message]
2021-02-26 7:18 ` [PATCH v3 2/8] mm/swapops: Rework swap entry manipulation code Alistair Popple
2021-02-26 16:00 ` Christoph Hellwig
2021-03-01 17:47 ` Jason Gunthorpe
2021-02-26 7:18 ` [PATCH v3 3/8] mm/rmap: Split try_to_munlock from try_to_unmap Alistair Popple
2021-02-26 16:01 ` Christoph Hellwig
2021-03-01 16:10 ` Jason Gunthorpe
2021-03-04 4:27 ` Alistair Popple
2021-02-26 7:18 ` [PATCH v3 4/8] mm/rmap: Split migration into its own function Alistair Popple
2021-02-26 16:03 ` Christoph Hellwig
[not found] ` <E93F89E1-3CE2-4CA3-97D9-6BCED78E1001@nvidia.com>
2021-03-04 23:54 ` Alistair Popple
2021-02-26 7:18 ` [PATCH v3 5/8] mm: Device exclusive memory access Alistair Popple
2021-03-01 17:54 ` Jason Gunthorpe
2021-03-01 22:55 ` Ralph Campbell
2021-03-02 0:05 ` Jason Gunthorpe
2021-03-02 8:57 ` Alistair Popple
[not found] ` <20210302124152.GF4247@nvidia.com>
2021-03-04 5:20 ` Alistair Popple
2021-02-26 7:18 ` [PATCH v3 6/8] mm: Selftests for exclusive device memory Alistair Popple
2021-03-01 17:55 ` Jason Gunthorpe
2021-03-01 18:07 ` Ralph Campbell
2021-03-01 23:14 ` Ralph Campbell
2021-03-02 9:12 ` Alistair Popple
2021-02-26 7:18 ` [PATCH v3 7/8] nouveau/svm: Refactor nouveau_range_fault Alistair Popple
2021-02-26 7:18 ` [PATCH v3 8/8] nouveau/svm: Implement atomic SVM access Alistair Popple
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3156280.dJpzq75PnV@nvdebian \
--to=apopple@nvidia.com \
--cc=akpm@linux-foundation.org \
--cc=bskeggs@redhat.com \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=hch@infradead.org \
--cc=jgg@nvidia.com \
--cc=jglisse@redhat.com \
--cc=jhubbard@nvidia.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=nouveau@lists.freedesktop.org \
--cc=rcampbell@nvidia.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).