From: Christoph Hellwig <hch@lst.de>
To: Christian Brauner <brauner@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>,
Chandan Babu R <chandan.babu@oracle.com>,
Zhang Yi <yi.zhang@huaweicloud.com>,
Ritesh Harjani <ritesh.list@gmail.com>,
Jens Axboe <axboe@kernel.dk>,
Andreas Gruenbacher <agruenba@redhat.com>,
Damien Le Moal <dlemoal@kernel.org>,
Naohiro Aota <naohiro.aota@wdc.com>,
Johannes Thumshirn <jth@kernel.org>,
linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-block@vger.kernel.org, gfs2@lists.linux.dev
Subject: map multiple blocks per ->map_blocks in iomap writeback
Date: Thu, 7 Dec 2023 08:26:56 +0100 [thread overview]
Message-ID: <20231207072710.176093-1-hch@lst.de> (raw)
Hi all,
this series overhaults a large chunk of the iomap writeback code with
the end result that ->map_blocks can now map multiple blocks at a time,
at least as long as they are all inside the same folio.
On a sufficiently large system (32 cores in my case) this significantly
reduces CPU usage for buffered write workloads on xfs, with a very minor
improvement in write bandwith that might be within the measurement
tolerance.
e.g. on a fio sequential write workload using io_uring I get these values
(median out of 5 runs):
before:
cpu : usr=5.26%, sys=4.81%, ctx=4009750, majf=0, minf=13
WRITE: bw=1096MiB/s (1150MB/s), 1096MiB/s-1096MiB/s (1150MB/s-1150MB/s), io=970GiB (1042GB), run=906036-906036msec
with this series:
cpu : usr=4.95%, sys=2.72%, ctx=4084578, majf=0, minf=12
WRITE: bw=1111MiB/s (1165MB/s), 1111MiB/s-1111MiB/s (1165MB/s-1165MB/s), io=980GiB (1052GB), run=903234-903234msec
On systems with a small number of cores the cpu usage reduction is much
lower and barely visible.
Changes since RFC:
- various commit message typo fixes
- minor formatting fixes
- keep the PF_MEMALLOC check and move it to iomap_writepages
- rename the offset argument to iomap_can_add_to_ioend to pos
- fix missing error handling in an earlier patch (only required for
bisection, no change to the end result)
- remove a stray whitespace
- refactor ifs_find_dirty_range a bit to make it more readable
- add a patch to pass the dirty_len to the file system to make life for
ext2 easier
Diffstat:
block/fops.c | 2
fs/gfs2/bmap.c | 2
fs/iomap/buffered-io.c | 576 +++++++++++++++++++++++--------------------------
fs/xfs/xfs_aops.c | 9
fs/zonefs/file.c | 3
include/linux/iomap.h | 19 +
6 files changed, 306 insertions(+), 305 deletions(-)
next reply other threads:[~2023-12-07 7:27 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-07 7:26 Christoph Hellwig [this message]
2023-12-07 7:26 ` [PATCH 01/14] iomap: clear the per-folio dirty bits on all writeback failures Christoph Hellwig
2023-12-07 7:26 ` [PATCH 02/14] iomap: treat inline data in iomap_writepage_map as an I/O error Christoph Hellwig
2023-12-07 7:26 ` [PATCH 03/14] iomap: move the io_folios field out of struct iomap_ioend Christoph Hellwig
2023-12-07 7:27 ` [PATCH 04/14] iomap: move the PF_MEMALLOC check to iomap_writepages Christoph Hellwig
2023-12-07 7:27 ` [PATCH 05/14] iomap: factor out a iomap_writepage_handle_eof helper Christoph Hellwig
2023-12-07 7:27 ` [PATCH 06/14] iomap: move all remaining per-folio logic into iomap_writepage_map Christoph Hellwig
2023-12-07 7:27 ` [PATCH 07/14] iomap: clean up the iomap_alloc_ioend calling convention Christoph Hellwig
2023-12-07 7:27 ` [PATCH 08/14] iomap: move the iomap_sector sector calculation out of iomap_add_to_ioend Christoph Hellwig
2023-12-07 7:27 ` [PATCH 09/14] iomap: don't chain bios Christoph Hellwig
2023-12-07 7:27 ` [PATCH 10/14] iomap: only call mapping_set_error once for each failed bio Christoph Hellwig
2023-12-07 7:27 ` [PATCH 11/14] iomap: factor out a iomap_writepage_map_block helper Christoph Hellwig
2023-12-07 7:27 ` [PATCH 12/14] iomap: submit ioends immediately Christoph Hellwig
2023-12-07 7:27 ` [PATCH 13/14] iomap: map multiple blocks at a time Christoph Hellwig
2023-12-07 13:39 ` Zhang Yi
2023-12-07 15:03 ` Christoph Hellwig
2023-12-08 7:33 ` Zhang Yi
2023-12-07 7:27 ` [PATCH 14/14] iomap: pass the length of the dirty region to ->map_blocks Christoph Hellwig
2023-12-11 10:45 ` map multiple blocks per ->map_blocks in iomap writeback Christian Brauner
2024-02-01 6:07 ` Christoph Hellwig
2024-02-01 6:18 ` Darrick J. Wong
2024-02-01 13:23 ` Christian Brauner
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