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| author |   Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2019-11-21 13:40:26 +0300 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2019-11-21 09:06:47 -0700 |
| commit | b6866318657717c8914673a6394894d12bc9ff5e (patch) | |
| tree | f4d534373b711f368f079d0cc54d3d71892e1feb /Documentation/ABI/testing/procfs-diskstats | |
| parent | block,bfq: Skip tracing hooks if possible (diff) | |
| download | linux-dev-b6866318657717c8914673a6394894d12bc9ff5e.tar.xz linux-dev-b6866318657717c8914673a6394894d12bc9ff5e.zip | |
block: add iostat counters for flush requests
Requests that triggers flushing volatile writeback cache to disk (barriers)
have significant effect to overall performance.
Block layer has sophisticated engine for combining several flush requests
into one. But there is no statistics for actual flushes executed by disk.
Requests which trigger flushes usually are barriers - zero-size writes.
This patch adds two iostat counters into /sys/class/block/$dev/stat and
/proc/diskstats - count of completed flush requests and their total time.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'Documentation/ABI/testing/procfs-diskstats')
| -rw-r--r-- | Documentation/ABI/testing/procfs-diskstats | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/procfs-diskstats b/Documentation/ABI/testing/procfs-diskstats index 2c44b4f1b060..70dcaf2481f4 100644 --- a/Documentation/ABI/testing/procfs-diskstats +++ b/Documentation/ABI/testing/procfs-diskstats @@ -29,4 +29,9 @@ Description: 17 - sectors discarded 18 - time spent discarding + Kernel 5.5+ appends two more fields for flush requests: + + 19 - flush requests completed successfully + 20 - time spent flushing + For more details refer to Documentation/admin-guide/iostats.rst |