From: Christoph Hellwig <hch@lst.de>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Carlos Maiolino <cem@kernel.org>,
linux-xfs@vger.kernel.org
Subject: Re: [PATCH 12/12] xfs: add lockless xfs_buf_readahead_map fast path
Date: Tue, 28 Jul 2026 06:41:11 +0200 [thread overview]
Message-ID: <20260728044111.GE20064@lst.de> (raw)
In-Reply-To: <20260724170316.GZ2901224@frogsfrogsfrogs>
On Fri, Jul 24, 2026 at 10:03:16AM -0700, Darrick J. Wong wrote:
> On Wed, Jul 15, 2026 at 04:51:05PM +0200, Christoph Hellwig wrote:
> > Readahead currently always locks the buffer, which can cause contention
> > with actual users of the buffer. Add a fast path without taking any
> > locks if the buffer is uptodate and not stale.
>
> So we're trying to cut down on b_sema contention for detecting the case
> where the buffer is already uptodate? And I guess the idea here is that
> if you had per-fsblock filesystem metadata, you'd want to be able to
> readahead that metadata into memory during setup for file IO without
> so much locking?
Yes.
next prev parent reply other threads:[~2026-07-28 4:41 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-15 14:50 misc buffer cache improvements Christoph Hellwig
2026-07-15 14:50 ` [PATCH 01/12] xfs: don't get a pag reference in xfs_buf_get_map Christoph Hellwig
2026-07-24 16:32 ` Darrick J. Wong
2026-07-15 14:50 ` [PATCH 02/12] xfs: consolidate buffer locking " Christoph Hellwig
2026-07-16 13:12 ` Brian Foster
2026-07-17 8:59 ` Christoph Hellwig
2026-07-17 14:13 ` Brian Foster
2026-07-20 7:59 ` Christoph Hellwig
2026-07-24 16:42 ` Darrick J. Wong
2026-07-28 4:38 ` Christoph Hellwig
2026-07-15 14:50 ` [PATCH 03/12] xfs: split out a lower-level xfs_buf_get_map helper from xfs_find_get_buf Christoph Hellwig
2026-07-24 16:44 ` Darrick J. Wong
2026-07-28 4:39 ` Christoph Hellwig
2026-07-15 14:50 ` [PATCH 04/12] xfs: remove spurious XBF_DONE clearing on readahead validation failure Christoph Hellwig
2026-07-24 16:45 ` Darrick J. Wong
2026-07-15 14:50 ` [PATCH 05/12] xfs: remove _XBF_LOGRECOVERY Christoph Hellwig
2026-07-24 16:49 ` Darrick J. Wong
2026-07-28 4:39 ` Christoph Hellwig
2026-07-15 14:50 ` [PATCH 06/12] xfs: hide b_flags manipulation from code outside of xfs_buf.c Christoph Hellwig
2026-07-24 16:49 ` Darrick J. Wong
2026-07-15 14:51 ` [PATCH 07/12] xfs: use WRITE_ONCE to update b_flags Christoph Hellwig
2026-07-24 16:53 ` Darrick J. Wong
2026-07-28 4:40 ` Christoph Hellwig
2026-07-15 14:51 ` [PATCH 08/12] xfs: don't reverify buffers in xfs_buf_readahead_map Christoph Hellwig
2026-07-24 16:56 ` Darrick J. Wong
2026-07-15 14:51 ` [PATCH 09/12] xfs: use goto based error unwinding in xfs_buf_read_map Christoph Hellwig
2026-07-24 16:57 ` Darrick J. Wong
2026-07-15 14:51 ` [PATCH 10/12] xfs: merge xfs_buf_reverify into xfs_buf_read_map Christoph Hellwig
2026-07-17 14:13 ` Brian Foster
2026-07-24 16:58 ` Darrick J. Wong
2026-07-15 14:51 ` [PATCH 11/12] xfs: move buffer locking out of xfs_find_get_buf Christoph Hellwig
2026-07-24 16:59 ` Darrick J. Wong
2026-07-15 14:51 ` [PATCH 12/12] xfs: add lockless xfs_buf_readahead_map fast path Christoph Hellwig
2026-07-24 17:03 ` Darrick J. Wong
2026-07-28 4:41 ` Christoph Hellwig [this message]
2026-08-10 11:55 ` misc buffer cache improvements Carlos Maiolino
-- strict thread matches above, loose matches on Subject: below --
2026-07-28 8:11 misc buffer cache improvements v2 Christoph Hellwig
2026-07-28 8:11 ` [PATCH 12/12] xfs: add lockless xfs_buf_readahead_map fast path Christoph Hellwig
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