From: Johan W. <joh...@gm...> - 2008-05-13 14:49:55
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Hi! All documentation I've found indicates that a vmlinux image is necessary for getting profiling results for the kernel. Couldn't OProfile use /proc/kallsyms to get kernel symbol information? If not, why not? Regards //Johan |
From: Johan W. <joh...@gm...> - 2008-05-20 05:51:10
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I never got a copy when sending this the last time, so I'm trying again. ---------- Forwarded message ---------- From: Johan Walles <joh...@gm...> Date: 2008/5/13 Subject: Using /proc/kallsyms rather than vmlinux? To: opr...@li... Hi! All documentation I've found indicates that a vmlinux image is necessary for getting profiling results for the kernel. Why can't oprofile use /proc/kallsyms instead to get kernel symbol information? Regards //Johan |
From: John L. <le...@mo...> - 2008-05-21 00:31:55
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On Tue, May 13, 2008 at 04:49:58PM +0200, Johan Walles wrote: > All documentation I've found indicates that a vmlinux image is > necessary for getting profiling results for the kernel. > > Couldn't OProfile use /proc/kallsyms to get kernel symbol information? What type of "file" is kallsyms? Is it just an ELF file? Have you tried it? john |
From: Andi K. <an...@fi...> - 2008-05-26 03:06:06
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John Levon <le...@mo...> writes: > > What type of "file" is kallsyms? Is it just an ELF file? Have you tried > it? It's like System.map An alternative would be to extend /proc/kcore to include ELF symbol tables from the kallsyms information. Advantage is that it would work with much more tools, including gdb or everything using BFD. I remember starting to implement that some years ago, but never finished it for some reason. -Andi |
From: Johan W. <joh...@gm...> - 2008-05-21 05:26:38
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It's a text file with about 48000 lines of address -> symbol mappings: johan@transwarp:~$ head /proc/kallsyms c0100000 T _text c0100000 T startup_32 c0100084 t bad_subarch c0100084 W lguest_entry c0100084 W xen_entry c0100086 t default_entry c01000e0 T startup_32_smp c0100160 t checkCPUtype c01001e1 t is486 c01001e8 t is386 johan@transwarp:~$ wc -l /proc/kallsyms 48448 /proc/kallsyms johan@transwarp:~$ Regards //Johan 2008/5/21 John Levon <le...@mo...>: > On Tue, May 13, 2008 at 04:49:58PM +0200, Johan Walles wrote: > >> All documentation I've found indicates that a vmlinux image is >> necessary for getting profiling results for the kernel. >> >> Couldn't OProfile use /proc/kallsyms to get kernel symbol information? > > What type of "file" is kallsyms? Is it just an ELF file? Have you tried > it? > > john > |
From: John L. <le...@mo...> - 2008-05-21 11:41:55
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On Wed, May 21, 2008 at 07:26:35AM +0200, Johan Walles wrote: > It's a text file with about 48000 lines of address -> symbol mappings: Then in theory, sure: you'd just have to add a new backend to op_bfd that understands the format. regards john |
From: Felipe C. <fel...@gm...> - 2008-05-21 16:08:41
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On Wed, May 21, 2008 at 2:41 PM, John Levon <le...@mo...> wrote: > On Wed, May 21, 2008 at 07:26:35AM +0200, Johan Walles wrote: > >> It's a text file with about 48000 lines of address -> symbol mappings: > > Then in theory, sure: you'd just have to add a new backend to op_bfd > that understands the format. That would be really nice. Johan, can you do that? Best regards. -- Felipe Contreras |
From: Johan W. <joh...@gm...> - 2008-05-23 14:32:48
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2008/5/21 Felipe Contreras <fel...@gm...>: > On Wed, May 21, 2008 at 2:41 PM, John Levon <le...@mo...> wrote: >> On Wed, May 21, 2008 at 07:26:35AM +0200, Johan Walles wrote: >> >>> It's a text file with about 48000 lines of address -> symbol mappings: >> >> Then in theory, sure: you'd just have to add a new backend to op_bfd >> that understands the format. > > That would be really nice. > > Johan, can you do that? No, sorry. //Johan |
From: Johan W. <joh...@gm...> - 2008-06-12 12:11:45
Attachments:
opkernel.rb
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Here's a ruby script that using "opreport -d" and the information in /proc/kallsyms lists the number of samples per kernel function. Just run it without any command line options after an oprofile run and it will print the kernel samples stats. //Johan 2008/5/13 Johan Walles <joh...@gm...>: > Hi! > > All documentation I've found indicates that a vmlinux image is > necessary for getting profiling results for the kernel. > > Why can't oprofile use /proc/kallsyms instead to get kernel symbol information? > > Regards //Johan > |