bgreg-performance

A cheat-sheet of performance-related tools by Brendan Gregg

Check this out: http://www.slideshare.net/brendangregg/meetbsd2014-performance-analysis

And this: http://www.brendangregg.com/USEmethod/use-rosetta.html

uptime

> uptime
>  09:26:00 up 11 days, 11:14, 11 users,  load average: 12.06, 6.81, 5.03

Primitive, don't spend a lot of time on these.

top/htop

Simple, can also give weighted CPU load averages

vmstat

> vmstat 1
> 
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 http://www.slideshare.net/brendangregg/linux-performance-analysis-new-tools-and-old-secrets?related=1
 ...

First line shows summary since boot. Then gives high level system summary after every one second (1 is the first argument). The summary includes schedular run queue, syscalls, memory, CPU states

iostat

Storage devices I/O statistics

> iostat -xx 1
avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.66   11.35    0.86    0.19    0.00   86.94

Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
sda               0.00     3.60    1.91    4.86    89.65  2579.38   394.05     0.43   63.05   3.58   2.43
dm-0              0.00     0.00    0.90    0.03    30.11     2.71    35.11     0.00    2.01   0.70   0.07
dm-1              0.00     0.00    0.96    3.04    57.69   821.66   219.76     0.31   77.14   2.39   0.96
dm-2              0.00     0.00    0.04    1.96     1.72    20.11    10.90     0.01    6.50   2.83   0.57
dm-3              0.00     0.00    0.00    3.19     0.01  1734.88   543.18     0.20   63.84   4.34   1.39
dm-4              0.00     0.00    0.00    0.00     0.01     0.02     8.08     0.00    2.83   1.85   0.00

systat

Network interface throughput, TCP statistics etc.

> systat -ifstat

dtrace

Instrument any software running on the system

> dtrace -ln 'fbt:::entry'