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Improve wording on how latency is measured
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sevan authored and yonghong-song committed Dec 12, 2019
1 parent 3106a82 commit 05a09ea
Showing 1 changed file with 3 additions and 3 deletions.
6 changes: 3 additions & 3 deletions man/man8/biolatency.8
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.TH biolatency 8 "2015-08-20" "USER COMMANDS"
.TH biolatency 8 "2019-12-12" "USER COMMANDS"
.SH NAME
biolatency \- Summarize block device I/O latency as a histogram.
.SH SYNOPSIS
Expand All @@ -8,8 +8,8 @@ biolatency traces block device I/O (disk I/O), and records the distribution
of I/O latency (time). This is printed as a histogram either on Ctrl-C, or
after a given interval in seconds.

The latency of the disk I/O is measured from the issue to the device to its
completion. A \-Q option can be used to include time queued in the kernel.
The latency of disk I/O operations is measured from when requests are issued to the device
up to completion. A \-Q option can be used to include time queued in the kernel.

This tool uses in-kernel eBPF maps for storing timestamps and the histogram,
for efficiency.
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