From: Linus Torvalds <torvalds@linux-foundation.org>
To: Kiryl Shutsemau <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>,
Luis Chamberlain <mcgrof@kernel.org>,
Linux-MM <linux-mm@kvack.org>,
linux-fsdevel@vger.kernel.org
Subject: Re: Optimizing small reads
Date: Mon, 6 Oct 2025 11:14:51 -0700 [thread overview]
Message-ID: <CAHk-=whG4TYkS+Ns0hbx4XNbvQN-BAvq9_ABJz1bgBsA4NPDAw@mail.gmail.com> (raw)
In-Reply-To: <5zq4qlllkr7zlif3dohwuraa7rukykkuu6khifumnwoltcijfc@po27djfyqbka>
On Mon, 6 Oct 2025 at 11:04, Kiryl Shutsemau <kirill@shutemov.name> wrote:
> >
> > So I think you can just change the seqcount_spinlock_t to a plain
> > seqcount_t with no locking at all, and document that external locking.
>
> That is not a spinlock. It is lockdep annotation that we expect this
> spinlock to be held there for seqcount write to be valid.
>
> It is NOP with lockdep disabled.
Ahh, right you are. Complaint withdrawn. I had the "lockref" kind of
thing in mind, but yes, the seqcount thing already have an external
lock model.
Linus
next prev parent reply other threads:[~2025-10-06 18:15 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-03 2:18 Linus Torvalds
2025-10-03 3:32 ` Luis Chamberlain
2025-10-15 21:31 ` Swarna Prabhu
2025-10-03 9:55 ` Kiryl Shutsemau
2025-10-03 16:18 ` Linus Torvalds
2025-10-03 16:40 ` Linus Torvalds
2025-10-03 17:23 ` Kiryl Shutsemau
2025-10-03 17:49 ` Linus Torvalds
2025-10-06 11:44 ` Kiryl Shutsemau
2025-10-06 15:50 ` Linus Torvalds
2025-10-06 18:04 ` Kiryl Shutsemau
2025-10-06 18:14 ` Linus Torvalds [this message]
2025-10-07 21:47 ` Linus Torvalds
2025-10-07 22:35 ` Linus Torvalds
2025-10-07 22:54 ` Linus Torvalds
2025-10-07 23:30 ` Linus Torvalds
2025-10-08 14:54 ` Kiryl Shutsemau
2025-10-08 16:27 ` Linus Torvalds
2025-10-08 17:03 ` Linus Torvalds
2025-10-09 16:22 ` Kiryl Shutsemau
2025-10-09 17:29 ` Linus Torvalds
2025-10-10 10:10 ` Kiryl Shutsemau
2025-10-10 17:51 ` Linus Torvalds
2025-10-13 15:35 ` Kiryl Shutsemau
2025-10-13 15:39 ` Kiryl Shutsemau
2025-10-13 16:19 ` Linus Torvalds
2025-10-14 12:58 ` Kiryl Shutsemau
2025-10-14 16:41 ` Linus Torvalds
2025-10-13 16:06 ` Linus Torvalds
2025-10-13 17:26 ` Theodore Ts'o
2025-10-14 3:20 ` Theodore Ts'o
2025-10-08 10:28 ` Kiryl Shutsemau
2025-10-08 16:24 ` Linus Torvalds
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