From: Christoph Hellwig <hch@infradead.org>
To: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>,
Mike Snitzer <snitzer@kernel.org>,
linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH 5/6] NFSD: leverage DIO alignment to selectively issue O_DIRECT reads and writes
Date: Thu, 12 Jun 2025 00:25:56 -0700 [thread overview]
Message-ID: <aEqBBLe0gi8w_VEl@infradead.org> (raw)
In-Reply-To: <21a1a0e28349824cc0a2937f719ec38d27089e3b.camel@kernel.org>
On Wed, Jun 11, 2025 at 11:07:20AM -0400, Jeff Layton wrote:
> > write data at least until the client sends a COMMIT. Otherwise the
> > server will have to convert all UNSTABLE writes to FILE_SYNC writes,
> > and that can have performance implications.
> >
>
> If we're doing synchronous, direct I/O writes then why not just respond
> with FILE_SYNC? The write should be on the platter by the time it
> returns.
Only if you do O_DSYNC writes. Which are painfully slow for lots of
configurations. Otherwise you still need to issue an fdatasync.
But can you help me refreshing why UNSTABLE semantics require having
the data in the page cache?
next prev parent reply other threads:[~2025-06-12 7:25 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-10 20:57 [PATCH 0/6] NFSD: add enable-dontcache and initially use it to add DIO support Mike Snitzer
2025-06-10 20:57 ` [PATCH 1/6] NFSD: add the ability to enable use of RWF_DONTCACHE for all IO Mike Snitzer
2025-06-11 6:57 ` Christoph Hellwig
2025-06-11 10:44 ` Mike Snitzer
2025-06-11 13:04 ` Jeff Layton
2025-06-11 13:56 ` Chuck Lever
2025-06-11 14:31 ` Chuck Lever
2025-06-11 19:18 ` Mike Snitzer
2025-06-11 20:29 ` Jeff Layton
2025-06-11 21:36 ` need SUNRPC TCP to receive into aligned pages [was: Re: [PATCH 1/6] NFSD: add the ability to enable use of RWF_DONTCACHE for all IO] Mike Snitzer
2025-06-12 10:28 ` Jeff Layton
2025-06-12 11:28 ` Jeff Layton
2025-06-12 13:28 ` Chuck Lever
2025-06-12 14:17 ` Benjamin Coddington
2025-06-12 15:56 ` Mike Snitzer
2025-06-12 15:58 ` Chuck Lever
2025-06-12 16:12 ` Mike Snitzer
2025-06-12 16:32 ` Chuck Lever
2025-06-13 5:39 ` Christoph Hellwig
2025-06-12 16:22 ` Jeff Layton
2025-06-13 5:46 ` Christoph Hellwig
2025-06-13 9:23 ` Mike Snitzer
2025-06-13 13:02 ` Jeff Layton
2025-06-16 12:35 ` Christoph Hellwig
2025-06-16 12:29 ` Christoph Hellwig
2025-06-16 16:07 ` Mike Snitzer
2025-06-17 4:37 ` Christoph Hellwig
2025-06-17 20:26 ` Mike Snitzer
2025-06-17 22:23 ` [RFC PATCH] lib/iov_iter: remove piecewise bvec length checking in iov_iter_aligned_bvec [was: Re: need SUNRPC TCP to receive into aligned pages] Mike Snitzer
2025-07-03 0:12 ` need SUNRPC TCP to receive into aligned pages [was: Re: [PATCH 1/6] NFSD: add the ability to enable use of RWF_DONTCACHE for all IO] NeilBrown
2025-06-12 7:13 ` [PATCH 1/6] NFSD: add the ability to enable use of RWF_DONTCACHE for all IO Christoph Hellwig
2025-06-12 13:15 ` Chuck Lever
2025-06-12 13:21 ` Chuck Lever
2025-06-12 16:00 ` Mike Snitzer
2025-06-16 13:32 ` Chuck Lever
2025-06-16 16:10 ` Mike Snitzer
2025-06-17 17:22 ` Mike Snitzer
2025-06-17 17:31 ` Chuck Lever
2025-06-19 20:19 ` Mike Snitzer
2025-06-30 14:50 ` Chuck Lever
2025-07-04 19:46 ` Mike Snitzer
2025-07-04 19:49 ` Chuck Lever
2025-06-10 20:57 ` [PATCH 2/6] NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support Mike Snitzer
2025-06-10 20:57 ` [PATCH 3/6] NFSD: pass nfsd_file to nfsd_iter_read() Mike Snitzer
2025-06-10 20:57 ` [PATCH 4/6] fs: introduce RWF_DIRECT to allow using O_DIRECT on a per-IO basis Mike Snitzer
2025-06-11 6:58 ` Christoph Hellwig
2025-06-11 10:51 ` Mike Snitzer
2025-06-11 14:17 ` Chuck Lever
2025-06-12 7:15 ` Christoph Hellwig
2025-06-10 20:57 ` [PATCH 5/6] NFSD: leverage DIO alignment to selectively issue O_DIRECT reads and writes Mike Snitzer
2025-06-11 7:00 ` Christoph Hellwig
2025-06-11 12:23 ` Mike Snitzer
2025-06-11 13:30 ` Jeff Layton
2025-06-12 7:22 ` Christoph Hellwig
2025-06-12 7:23 ` Christoph Hellwig
2025-06-11 14:42 ` Chuck Lever
2025-06-11 15:07 ` Jeff Layton
2025-06-11 15:11 ` Chuck Lever
2025-06-11 15:44 ` Jeff Layton
2025-06-11 20:51 ` Mike Snitzer
2025-06-12 7:32 ` Christoph Hellwig
2025-06-12 7:28 ` Christoph Hellwig
2025-06-12 7:25 ` Christoph Hellwig [this message]
2025-06-10 20:57 ` [PATCH 6/6] NFSD: issue READs using O_DIRECT even if IO is misaligned Mike Snitzer
2025-06-11 12:55 ` [PATCH 0/6] NFSD: add enable-dontcache and initially use it to add DIO support Jeff Layton
2025-06-12 7:39 ` Christoph Hellwig
2025-06-12 20:37 ` Mike Snitzer
2025-06-13 5:31 ` Christoph Hellwig
2025-06-11 14:16 ` Chuck Lever
2025-06-11 18:02 ` Mike Snitzer
2025-06-11 19:06 ` Chuck Lever
2025-06-11 19:58 ` Mike Snitzer
2025-06-12 13:46 ` Chuck Lever
2025-06-12 19:08 ` Mike Snitzer
2025-06-12 20:17 ` Chuck Lever
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