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| author | Mikulas Patocka <mpatocka@redhat.com> | 2020-01-15 04:35:22 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2020-01-16 13:34:17 -0500 |
| commit | dcd195071f22d4770911ca46694ca398b6d5101d (patch) | |
| tree | caa113ebf22d61d9034bc36fee85cb81b6061f69 /drivers/nubus | |
| parent | be240ff5e402df49c4ddbcb0595ef96009239f6a (diff) | |
| download | lwn-dcd195071f22d4770911ca46694ca398b6d5101d.tar.gz lwn-dcd195071f22d4770911ca46694ca398b6d5101d.zip | |
dm writecache: improve performance of large linear writes on SSDs
When dm-writecache is used with SSD as a cache device, it would submit a
separate bio for each written block. The I/Os would be merged by the disk
scheduler, but this merging degrades performance.
Improve dm-writecache performance by submitting larger bios - this is
possible as long as there is consecutive free space on the cache
device.
Benchmark (arm64 with 64k page size, using /dev/ram0 as a cache device):
fio --bs=512k --iodepth=32 --size=400M --direct=1 \
--filename=/dev/mapper/cache --rw=randwrite --numjobs=1 --name=test
block old new
size MiB/s MiB/s
---------------------
512 181 700
1k 347 1256
2k 644 2020
4k 1183 2759
8k 1852 3333
16k 2469 3509
32k 2974 3670
64k 3404 3810
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/nubus')
0 files changed, 0 insertions, 0 deletions