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From: Jens Axboe <axboe@kernel.dk>
To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Cc: akpm@linux-foundation.org
Subject: [PATCHSET v3 0/3] Improve IOCB_NOWAIT O_DIRECT reads
Date: Wed, 24 Feb 2021 09:44:52 -0700	[thread overview]
Message-ID: <20210224164455.1096727-1-axboe@kernel.dk> (raw)

Hi,

For v1, see:

https://lore.kernel.org/linux-fsdevel/20210208221829.17247-1-axboe@kernel.dk/

tldr; don't -EAGAIN IOCB_NOWAIT dio reads just because we have page cache
entries for the given range. This causes unnecessary work from the callers
side, when the IO could have been issued totally fine without blocking on
writeback when there is none.

 fs/iomap/direct-io.c | 24 ++++++++++++++--------
 include/linux/fs.h   |  2 ++
 mm/filemap.c         | 47 ++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 63 insertions(+), 10 deletions(-)

Andrew, any chance you can pick this up for 5.12?

Since v2:
- Drop overly long line (hch)
- Rebase to master, iomap changed flags to iomap_flags

-- 
Jens Axboe



             reply	other threads:[~2021-02-24 16:46 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-24 16:44 Jens Axboe [this message]
2021-02-24 16:44 ` [PATCH 1/3] mm: provide filemap_range_needs_writeback() helper Jens Axboe
2021-02-24 16:50   ` Matthew Wilcox
2021-02-24 16:53     ` Jens Axboe
2021-02-24 17:22   ` Jan Kara
2021-02-24 16:44 ` [PATCH 2/3] mm: use filemap_range_needs_writeback() for O_DIRECT reads Jens Axboe
2021-02-24 16:57   ` Matthew Wilcox
2021-02-24 17:23   ` Jan Kara
2021-02-24 16:44 ` [PATCH 3/3] iomap: " Jens Axboe
2021-02-24 17:25   ` Jan Kara

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