Based on kernel version 4.9. Page generated on 2016-12-21 14:28 EST.
1 These instructions are deliberately very basic. If you want something clever, 2 go read the real docs ;-) Please don't add more stuff, but feel free to 3 correct my mistakes ;-) (mbligh@aracnet.com) 4 Thanks to John Levon, Dave Hansen, et al. for help writing this. 5 6 <test> is the thing you're trying to measure. 7 Make sure you have the correct System.map / vmlinux referenced! 8 9 It is probably easiest to use "make install" for linux and hack 10 /sbin/installkernel to copy vmlinux to /boot, in addition to vmlinuz, 11 config, System.map, which are usually installed by default. 12 13 Readprofile 14 ----------- 15 A recent readprofile command is needed for 2.6, such as found in util-linux 16 2.12a, which can be downloaded from: 17 18 http://www.kernel.org/pub/linux/utils/util-linux/ 19 20 Most distributions will ship it already. 21 22 Add "profile=2" to the kernel command line. 23 24 clear readprofile -r 25 <test> 26 dump output readprofile -m /boot/System.map > captured_profile 27 28 Oprofile 29 -------- 30 31 Get the source (see Changes for required version) from 32 http://oprofile.sourceforge.net/ and add "idle=poll" to the kernel command 33 line. 34 35 Configure with CONFIG_PROFILING=y and CONFIG_OPROFILE=y & reboot on new kernel 36 37 ./configure --with-kernel-support 38 make install 39 40 For superior results, be sure to enable the local APIC. If opreport sees 41 a 0Hz CPU, APIC was not on. Be aware that idle=poll may mean a performance 42 penalty. 43 44 One time setup: 45 opcontrol --setup --vmlinux=/boot/vmlinux 46 47 clear opcontrol --reset 48 start opcontrol --start 49 <test> 50 stop opcontrol --stop 51 dump output opreport > output_file 52 53 To only report on the kernel, run opreport -l /boot/vmlinux > output_file 54 55 A reset is needed to clear old statistics, which survive a reboot.