1These instructions are deliberately very basic. If you want something clever, 2go read the real docs ;-) Please don't add more stuff, but feel free to 3correct my mistakes ;-) (mbligh@aracnet.com) 4Thanks to John Levon, Dave Hansen, et al. for help writing this. 5 6<test> is the thing you're trying to measure. 7Make sure you have the correct System.map / vmlinux referenced! 8 9It is probably easiest to use "make install" for linux and hack 10/sbin/installkernel to copy vmlinux to /boot, in addition to vmlinuz, 11config, System.map, which are usually installed by default. 12 13Readprofile 14----------- 15A recent readprofile command is needed for 2.6, such as found in util-linux 162.12a, which can be downloaded from: 17 18http://www.kernel.org/pub/linux/utils/util-linux/ 19 20Most distributions will ship it already. 21 22Add "profile=2" to the kernel command line. 23 24clear readprofile -r 25 <test> 26dump output readprofile -m /boot/System.map > captured_profile 27 28Oprofile 29-------- 30 31Get the source (see Changes for required version) from 32http://oprofile.sourceforge.net/ and add "idle=poll" to the kernel command 33line. 34 35Configure with CONFIG_PROFILING=y and CONFIG_OPROFILE=y & reboot on new kernel 36 37./configure --with-kernel-support 38make install 39 40For superior results, be sure to enable the local APIC. If opreport sees 41a 0Hz CPU, APIC was not on. Be aware that idle=poll may mean a performance 42penalty. 43 44One time setup: 45 opcontrol --setup --vmlinux=/boot/vmlinux 46 47clear opcontrol --reset 48start opcontrol --start 49 <test> 50stop opcontrol --stop 51dump output opreport > output_file 52 53To only report on the kernel, run opreport -l /boot/vmlinux > output_file 54 55A reset is needed to clear old statistics, which survive a reboot. 56 57