From: Peter Zijlstra <peterz@infradead.org>
To: David Hildenbrand <david@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>,
akpm@linux-foundation.org, andrii@kernel.org, jannh@google.com,
Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com,
vbabka@suse.cz, mhocko@kernel.org, shakeel.butt@linux.dev,
hannes@cmpxchg.org, willy@infradead.org, brauner@kernel.org,
oleg@redhat.com, arnd@arndb.de, richard.weiyang@gmail.com,
zhangpeng.00@bytedance.com, linmiaohe@huawei.com,
viro@zeniv.linux.org.uk, hca@linux.ibm.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/3] seqlock: add raw_seqcount_try_begin
Date: Fri, 22 Nov 2024 12:19:14 +0100 [thread overview]
Message-ID: <20241122111914.GS24774@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <46aa36f0-64a6-4aee-8134-0ec93f62e59c@redhat.com>
On Fri, Nov 22, 2024 at 12:10:29PM +0100, David Hildenbrand wrote:
> In gup_fast(), we simply do
>
> seq = raw_read_seqcount(¤t->mm->write_protect_seq);
> if (seq & 1)
> return 0;
>
> Should we be using that there as well?
>
> if (!raw_seqcount_try_begin(¤t->mm->write_protect_seqs, seq))
> return 0;
Might as well. A quick grep doesn't find me another instance of this
pattern, but does find me something 'funny' in net/netfilter/x_tables.c.
Let's pretend I didn't see that for now ... *sigh*
Want me to stick a patch like this on, or do you want to do that later,
when the dust has settled?
next prev parent reply other threads:[~2024-11-22 11:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-21 16:28 [PATCH v2 1/3] seqlock: add raw_seqcount_try_begin Suren Baghdasaryan
2024-11-21 16:28 ` [PATCH v2 2/3] mm: convert mm_lock_seq to a proper seqcount Suren Baghdasaryan
2024-11-22 15:14 ` Liam R. Howlett
2024-11-22 16:52 ` kernel test robot
2024-11-22 17:17 ` Suren Baghdasaryan
2024-11-22 17:49 ` Suren Baghdasaryan
2024-11-22 19:37 ` kernel test robot
2024-11-21 16:28 ` [PATCH v2 3/3] mm: introduce mmap_lock_speculate_{try_begin|retry} Suren Baghdasaryan
2024-11-22 11:05 ` Peter Zijlstra
2024-11-22 15:03 ` Suren Baghdasaryan
2024-11-22 15:15 ` Liam R. Howlett
2024-11-22 11:10 ` [PATCH v2 1/3] seqlock: add raw_seqcount_try_begin David Hildenbrand
2024-11-22 11:19 ` Peter Zijlstra [this message]
2024-11-22 11:21 ` David Hildenbrand
2024-11-22 15:13 ` Liam R. Howlett
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