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-------- 30Get the source (I use 0.8) from http://oprofile.sourceforge.net/ 31and add "idle=poll" to the kernel command line 32Configure with CONFIG_PROFILING=y and CONFIG_OPROFILE=y & reboot on new kernel 33./configure --with-kernel-support 34make install 35 36For superior results, be sure to enable the local APIC. If opreport sees 37a 0Hz CPU, APIC was not on. Be aware that idle=poll may mean a performance 38penalty. 39 40One time setup: 41 opcontrol --setup --vmlinux=/boot/vmlinux 42 43clear opcontrol --reset 44start opcontrol --start 45 <test> 46stop opcontrol --stop 47dump output opreport > output_file 48 49To only report on the kernel, run opreport /boot/vmlinux > output_file 50 51A reset is needed to clear old statistics, which survive a reboot. 52 53