From: Peter Xu <peterx@redhat.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Hellwig <hch@lst.de>, Hugh Dickins <hughd@google.com>,
Jan Kara <jack@suse.cz>, Jann Horn <jannh@google.com>,
John Hubbard <jhubbard@nvidia.com>,
Kirill Shutemov <kirill@shutemov.name>,
Kirill Tkhai <ktkhai@virtuozzo.com>,
Linux-MM <linux-mm@kvack.org>, Michal Hocko <mhocko@suse.com>,
Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH v2 1/2] mm: reorganize internal_get_user_pages_fast()
Date: Fri, 30 Oct 2020 18:36:55 -0400 [thread overview]
Message-ID: <20201030223655.GA6357@xz-x1> (raw)
In-Reply-To: <1-v2-dfe9ecdb6c74+2066-gup_fork_jgg@nvidia.com>
On Fri, Oct 30, 2020 at 11:46:20AM -0300, Jason Gunthorpe wrote:
> The next patch in this series makes the lockless flow a little more
> complex, so move the entire block into a new function and remove a level
> of indention. Tidy a bit of cruft:
>
> - addr is always the same as start, so use start
>
> - Use the modern check_add_overflow() for computing end = start + len
>
> - nr_pinned/pages << PAGE_SHIFT needs the LHS to be unsigned long to
> avoid shift overflow, make the variables unsigned long to avoid coding
> casts in both places. nr_pinned was missing its cast
>
> - The handling of ret and nr_pinned can be streamlined a bit
>
> No functional change.
>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Sorry for a very late reply (due to other distractions):
Reviewed-by: Peter Xu <peterx@redhat.com>
Thanks,
--
Peter Xu
next prev parent reply other threads:[~2020-10-30 22:37 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <0-v2-dfe9ecdb6c74+2066-gup_fork_jgg@nvidia.com>
2020-10-30 14:46 ` [PATCH v2 1/2] mm: reorganize internal_get_user_pages_fast() Jason Gunthorpe
2020-10-30 16:29 ` Jan Kara
2020-10-30 21:31 ` John Hubbard
2020-10-30 22:36 ` Peter Xu [this message]
2020-11-02 22:19 ` [PATCH v2 0/2] Add a seqcount between gup_fast and copy_page_range() Ahmed S. Darwish
2020-11-02 22:39 ` Linus Torvalds
2020-11-02 23:18 ` Ahmed S. Darwish
[not found] ` <2-v2-dfe9ecdb6c74+2066-gup_fork_jgg@nvidia.com>
2020-10-30 16:51 ` [PATCH v2 2/2] mm: prevent gup_fast from racing with COW during fork Jan Kara
[not found] ` <20201030170226.GF2620339@nvidia.com>
2020-11-02 8:31 ` Jan Kara
2020-10-30 22:52 ` Peter Xu
[not found] ` <20201030235121.GQ2620339@nvidia.com>
2020-10-31 15:26 ` Peter Xu
2020-11-03 0:33 ` Ahmed S. Darwish
2020-11-03 0:17 ` Ahmed S. Darwish
[not found] ` <20201103002532.GL2620339@nvidia.com>
2020-11-03 0:41 ` Ahmed S. Darwish
2020-11-03 2:20 ` John Hubbard
2020-11-03 6:52 ` Ahmed S. Darwish
2020-11-03 17:40 ` Linus Torvalds
2020-11-04 1:32 ` Ahmed S. Darwish
2020-11-04 2:01 ` John Hubbard
2020-11-04 3:17 ` Ahmed S. Darwish
2020-11-04 18:38 ` Linus Torvalds
2020-11-04 19:54 ` Ahmed S. Darwish
2020-12-09 18:38 ` [tip: locking/core] seqlock: Prefix internal seqcount_t-only macros with a "do_" tip-bot2 for Ahmed S. Darwish
2020-12-09 18:38 ` [tip: locking/core] seqlock: kernel-doc: Specify when preemption is automatically altered tip-bot2 for Ahmed S. Darwish
2020-11-10 11:53 ` [PATCH v2 2/2] mm: prevent gup_fast from racing with COW during fork Peter Zijlstra
2020-12-03 10:35 ` [tip: locking/core] seqlock: Rename __seqprop() users tip-bot2 for Peter Zijlstra
2020-11-03 17:03 ` [PATCH v2 2/2] mm: prevent gup_fast from racing with COW during fork Peter Xu
2020-11-02 23:58 ` Ahmed S. Darwish
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