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56 lines
1.7 KiB
56 lines
1.7 KiB
These instructions are deliberately very basic. If you want something clever, |
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go read the real docs ;-) Please don't add more stuff, but feel free to |
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correct my mistakes ;-) (mbligh@aracnet.com) |
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Thanks to John Levon, Dave Hansen, et al. for help writing this. |
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<test> is the thing you're trying to measure. |
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Make sure you have the correct System.map / vmlinux referenced! |
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It is probably easiest to use "make install" for linux and hack |
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/sbin/installkernel to copy vmlinux to /boot, in addition to vmlinuz, |
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config, System.map, which are usually installed by default. |
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Readprofile |
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----------- |
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A recent readprofile command is needed for 2.6, such as found in util-linux |
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2.12a, which can be downloaded from: |
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http://www.kernel.org/pub/linux/utils/util-linux/ |
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Most distributions will ship it already. |
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Add "profile=2" to the kernel command line. |
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clear readprofile -r |
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<test> |
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dump output readprofile -m /boot/System.map > captured_profile |
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Oprofile |
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-------- |
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Get the source (see Changes for required version) from |
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http://oprofile.sourceforge.net/ and add "idle=poll" to the kernel command |
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line. |
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Configure with CONFIG_PROFILING=y and CONFIG_OPROFILE=y & reboot on new kernel |
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./configure --with-kernel-support |
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make install |
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For superior results, be sure to enable the local APIC. If opreport sees |
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a 0Hz CPU, APIC was not on. Be aware that idle=poll may mean a performance |
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penalty. |
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One time setup: |
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opcontrol --setup --vmlinux=/boot/vmlinux |
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clear opcontrol --reset |
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start opcontrol --start |
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<test> |
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stop opcontrol --stop |
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dump output opreport > output_file |
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To only report on the kernel, run opreport -l /boot/vmlinux > output_file |
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A reset is needed to clear old statistics, which survive a reboot. |
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