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brendangregg / gist:1453467
Created Dec 9, 2011
libmicro mprot_tw128k testing
View gist:1453467
[root@smartos18 ~/utils/libMicro-0.4.1/bin]# ./mprotect -N "mprot_tw128k" -l 128k -I 2000 -w -t -f /dev/zero
prc thr usecs/call samples errors cnt/samp size flags
mprot_tw128k 1 1 1.63200 219 0 1 131072 --w-t
[root@smartos18 ~/utils/libMicro-0.4.1/bin]# ./mprotect -N "mprot_tw128k" -l 128k -I 2000 -w -t -f /dev/zero
prc thr usecs/call samples errors cnt/samp size flags
mprot_tw128k 1 1 67.25900 205 0 1 131072 --w-t
[root@smartos18 ~/utils/libMicro-0.4.1/bin]# ./mprotect -N "mprot_tw128k" -l 128k -I 2000 -w -t -f /dev/zero
prc thr usecs/call samples errors cnt/samp size flags
mprot_tw128k 1 1 106.88600 135 0 1 131072 --w-t
@brendangregg
brendangregg / tcpretranssnoop_sdc6.d
Created Feb 10, 2012
TCP retrans snoop for SDC6
View tcpretranssnoop_sdc6.d
#!/usr/sbin/dtrace -s
/*
* tcpretranssnoop.d Trace TCP retransmitted segments with details.
*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
@brendangregg
brendangregg / gist:1954156
Created Mar 2, 2012
queueing theory for sphinx
View gist:1954156
run time (ms):
searchd
value ------------- Distribution ------------- count
< 0 | 0
0 |@@@@@@@@@@@@@@@@@ 1745
100 |@@@@ 363
200 |@@@ 287
300 |@@ 175
400 |@ 106
@brendangregg
brendangregg / gist:1997991
Created Mar 8, 2012
systemtap comparing profiling rates on fedora
View gist:1997991
[root@fedora1 admin]# stap -e 'global s, last; probe begin { last = gettimeofday_ns(); } probe timer.profile { now = gettimeofday_ns(); s <<< now - last; last = now; } probe timer.s(10) { printf("ns\n"); print(@hist_linear(s, 900000, 1100000, 10000)); exit(); }'
ns
value |-------------------------------------------------- count
<900000 | 80
900000 | 17
910000 | 15
920000 | 7
930000 | 8
940000 | 17
950000 | 15
@brendangregg
brendangregg / gist:2014938
Created Mar 11, 2012
DTrace Mac OS X launchd write origin
View gist:2014938
root@macbook:~> dtrace -n 'io:::start /!(args[0]->b_flags & B_READ) && execname == "launchd"/ { trace(execname); stack(); }'
dtrace: description 'io:::start ' matched 1 probe
CPU ID FUNCTION:NAME
0 19368 buf_strategy:start launchd
mach_kernel`buf_strategy+0x5e
mach_kernel`hfs_vnop_strategy+0x34
mach_kernel`VNOP_STRATEGY+0x2f
mach_kernel`buf_bwrite+0x257
mach_kernel`hfs_vnop_bwrite+0x12a
mach_kernel`VNOP_BWRITE+0x2f
@brendangregg
brendangregg / gist:2670942
Created May 13, 2012
node.js fs.readFile analysis
View gist:2670942
Here's some more perf analysis: what was the limiter for node.js in the original fs.readFile benchmark,
causing large performance difference?
Examining thread microstates using prstat (SmartOS):
# prstat -mLcp 92432 1
Please wait...
[...]
PID USERNAME USR SYS TRP TFL DFL LCK SLP LAT VCX ICX SCL SIG PROCESS/LWPID
92432 root 90 10 0.0 0.0 0.0 0.0 0.0 0.0 7 9 42K 0 node/1
View gist:2855241
#!/usr/bin/sh
#
# intelcpi - measure CPI and utilization on Intel processors.
#
# USAGE: intelcpi [interval]
# eg,
# intelcpi 0.1 # for 0.1 second intervals
#
# CPI shows how memory intensive CPU workloads are.
#
View gist:4695917
2 problems:
1. ignores runtime
2. doesn't output actual measurements (other than issued total)
[~/fio-2.0.13]# time ./fio --name=randread --rw=randread --random_distribution=pareto:0.5 --size=1g --bs=8k --runtime=10 --time_based --filename=fio.tmp
randread: (g=0): rw=randread, bs=8K-8K/8K-8K/8K-8K, ioengine=sync, iodepth=1
fio-2.0.13
Starting 1 process
^C
@brendangregg
brendangregg / gist:4743398
Last active Dec 12, 2015
mac_rx to freemsg latency (RX IP stack latency)
View gist:4743398
[root@headnode /var/tmp/brendan]# cat rxstacklat.d
#!/usr/sbin/dtrace -s
fbt::mac_rx:entry
{
ts[arg2] = timestamp;
}
fbt::freemsg:entry,
fbt::freeb:entry
View gist:5147879
# dtrace -Fn 'fbt::mac_tx_send:entry /execname == "ping"/ { self->in = 1; } fbt::mac_tx_send:return { exit(0); } fbt:mac:: { trace(timestamp); }'
dtrace: description 'fbt::mac_tx_send:entry ' matched 1410 probes
CPU FUNCTION
8 -> mac_tx 13822389790096059
8 -> mac_protect_check 13822389790102650
8 -> mac_protect_check_one 13822389790104778
8 -> mac_vlan_header_info 13822389790106716
8 -> mac_header_info 13822389790107876
8 <- mac_header_info 13822389790108803
8 <- mac_vlan_header_info 13822389790110092