Re: Profiling code execution on amd64?
Last time i've used it it was working but I dont think it is really useful now (from my POV) because you cant have a global view of the system with it and all other reports overlap. With the current state you have: - top mode for fast lookup - text output (replace gprof for me) - kcachegrind (calltree) for in depth analysis - gprof Fabien On Fri, Jan 14, 2011 at 10:10 PM, Steve Kargl s...@troutmask.apl.washington.edu wrote: On Fri, Jan 14, 2011 at 03:40:46PM -0500, George Neville-Neil wrote: On Jan 13, 2011, at 23:05 , Steve Kargl wrote: On Thu, Jan 13, 2011 at 10:08:30PM -0500, Ryan Stone wrote: I would suggest using hwpmc for profiling: # kldload hwpmc # pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration # pmcstat -R /tmp/samples.out -G /tmp/penetration.txt You can also get pmcstat to generate gprof-compatible output with -g, but I never use the mode so I'm really not sure what it gives you. I think that you have to run gprof on the output or something, but don't hold me to that. Thanks. I'll give it a try, but my initial attempt seems to indicate that one needs to be root to use hwpmc. laptop:kargl[210] pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration pmcstat: ERROR: Cannot allocate system-mode pmc with specification unhalted-cycles: Operation not permitted You only need to be root to profile the kernel or someone else's process. This tutorial might help: www.dcbsdcon.org/speakers/slides/neville-neil_dcbsdcon2009.pdf Thanks. I'll look at the tutorial. Meanwhile, should gprof be removed from the base system because it appears broken? Instead of just removing things, why not determine why things are broken and try to fix them? -Garrett ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
Re: Profiling code execution on amd64?
On Mon, Jan 17, 2011 at 09:45:44AM +0100, Fabien Thomas wrote: Last time i've used it it was working but I dont think it is really useful now (from my POV) because you cant have a global view of the system with it and all other reports overlap. To what does 'it' refer? With the current state you have: - top mode for fast lookup - text output (replace gprof for me) - kcachegrind (calltree) for in depth analysis - gprof Please, don't top post, and check to see if the 'enter' key on your computer is functioning properly. -- Steve ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
Re: Profiling code execution on amd64?
On 01/15/11 07:15, Garrett Cooper wrote: On Fri, Jan 14, 2011 at 10:10 PM, Steve Kargl s...@troutmask.apl.washington.edu wrote: On Fri, Jan 14, 2011 at 03:40:46PM -0500, George Neville-Neil wrote: On Jan 13, 2011, at 23:05 , Steve Kargl wrote: On Thu, Jan 13, 2011 at 10:08:30PM -0500, Ryan Stone wrote: I would suggest using hwpmc for profiling: # kldload hwpmc # pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration # pmcstat -R /tmp/samples.out -G /tmp/penetration.txt You can also get pmcstat to generate gprof-compatible output with -g, but I never use the mode so I'm really not sure what it gives you. I think that you have to run gprof on the output or something, but don't hold me to that. Thanks. I'll give it a try, but my initial attempt seems to indicate that one needs to be root to use hwpmc. laptop:kargl[210] pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration pmcstat: ERROR: Cannot allocate system-mode pmc with specification unhalted-cycles: Operation not permitted You only need to be root to profile the kernel or someone else's process. This tutorial might help: www.dcbsdcon.org/speakers/slides/neville-neil_dcbsdcon2009.pdf Thanks. I'll look at the tutorial. Meanwhile, should gprof be removed from the base system because it appears broken? Instead of just removing things, why not determine why things are broken and try to fix them? -Garrett gprof is not as badly broken as it seems 8-) I have encountered the issue described by the original poster regularly over the last few years, using different versions of FreeBSD. The total time reported by gprof is often way shorter than the time reported by time. I have checked that the problem goes back to at least 7.3-RELEASE, and it occurs on both amd64 and i386. I found that this problem is caused by neither the profile start-up code nor gprof knowing about dynamic linking. The start-up code calls profil() with etext as the upper limit of the address range to be profiled. This implies that all dynamically linked code will not be profiled, which explains the lost ticks in gprof. A solution might be to teach both the profiling start-up code and gprof about dynamic linking, but I guess that is not that trivial ... A good work-around is linking statically (-static). Also be aware that with dynamic linking and specifying -pg, a profiled (and static!) version is used only for the C library. So if e.g. the math library is needed -lm_p has to be specified explicitly instead of just -lm, or ticks will be lost. So specifying standard libraries with _p appended might already solve most of the problems. I also remember (and just verified) that in the good old days (FreeBSD 2.2.8) static linking took place automatically when profiling was requested, so the issues at hand might not even be new 8-) Kind regards, Hans Ottevanger PS. Thanks for the link to your tutorial, George. I am very interested in hwpmc, and since documentation seems to be somewhat sparse, this really helps. ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
Re: Profiling code execution on amd64?
On Jan 13, 2011, at 23:05 , Steve Kargl wrote: On Thu, Jan 13, 2011 at 10:08:30PM -0500, Ryan Stone wrote: I would suggest using hwpmc for profiling: # kldload hwpmc # pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration # pmcstat -R /tmp/samples.out -G /tmp/penetration.txt You can also get pmcstat to generate gprof-compatible output with -g, but I never use the mode so I'm really not sure what it gives you. I think that you have to run gprof on the output or something, but don't hold me to that. Thanks. I'll give it a try, but my initial attempt seems to indicate that one needs to be root to use hwpmc. laptop:kargl[210] pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration pmcstat: ERROR: Cannot allocate system-mode pmc with specification unhalted-cycles: Operation not permitted You only need to be root to profile the kernel or someone else's process. This tutorial might help: www.dcbsdcon.org/speakers/slides/neville-neil_dcbsdcon2009.pdf Best, George ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
Re: Profiling code execution on amd64?
On Fri, Jan 14, 2011 at 03:40:46PM -0500, George Neville-Neil wrote: On Jan 13, 2011, at 23:05 , Steve Kargl wrote: On Thu, Jan 13, 2011 at 10:08:30PM -0500, Ryan Stone wrote: I would suggest using hwpmc for profiling: # kldload hwpmc # pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration # pmcstat -R /tmp/samples.out -G /tmp/penetration.txt You can also get pmcstat to generate gprof-compatible output with -g, but I never use the mode so I'm really not sure what it gives you. I think that you have to run gprof on the output or something, but don't hold me to that. Thanks. I'll give it a try, but my initial attempt seems to indicate that one needs to be root to use hwpmc. laptop:kargl[210] pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration pmcstat: ERROR: Cannot allocate system-mode pmc with specification unhalted-cycles: Operation not permitted You only need to be root to profile the kernel or someone else's process. This tutorial might help: www.dcbsdcon.org/speakers/slides/neville-neil_dcbsdcon2009.pdf Thanks. I'll look at the tutorial. Meanwhile, should gprof be removed from the base system because it appears broken? -- Steve ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
Re: Profiling code execution on amd64?
On Fri, Jan 14, 2011 at 10:10 PM, Steve Kargl s...@troutmask.apl.washington.edu wrote: On Fri, Jan 14, 2011 at 03:40:46PM -0500, George Neville-Neil wrote: On Jan 13, 2011, at 23:05 , Steve Kargl wrote: On Thu, Jan 13, 2011 at 10:08:30PM -0500, Ryan Stone wrote: I would suggest using hwpmc for profiling: # kldload hwpmc # pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration # pmcstat -R /tmp/samples.out -G /tmp/penetration.txt You can also get pmcstat to generate gprof-compatible output with -g, but I never use the mode so I'm really not sure what it gives you. I think that you have to run gprof on the output or something, but don't hold me to that. Thanks. I'll give it a try, but my initial attempt seems to indicate that one needs to be root to use hwpmc. laptop:kargl[210] pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration pmcstat: ERROR: Cannot allocate system-mode pmc with specification unhalted-cycles: Operation not permitted You only need to be root to profile the kernel or someone else's process. This tutorial might help: www.dcbsdcon.org/speakers/slides/neville-neil_dcbsdcon2009.pdf Thanks. I'll look at the tutorial. Meanwhile, should gprof be removed from the base system because it appears broken? Instead of just removing things, why not determine why things are broken and try to fix them? -Garrett ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
Profiling code execution on amd64?
How does one profile one's code on freebsd-amd64? It seems that gprof is broken. troutmask:kargl[234] time ../penetration CPU time: 7.327 min Start time: 2011-01-13 08:59:18.419 Stop time: 2011-01-13 09:06:39.082 CPU time: 7.34 min 440.68 real 440.25 user 0.11 sys troutmask:kargl[235] gprof -b -l ../penetration penetration.gmon | more granularity: each sample hit covers 4 byte(s) for 0.00% of 25.46 seconds % cumulative self self total time seconds secondscalls ms/call ms/call name 96.2 24.4824.48 282440 0.09 0.09 __mempoolm_MOD_memadd [4] 1.4 24.84 0.350 100.00% _mcount [5] 0.7 25.03 0.191 188.65 188.82 __srfm_MOD_rms [6] 0.5 25.14 0.12 608847 0.00 0.00 memcpy [11] I cannot reconcile how 440.25 seconds is the same a 25.46. Should src/usr.bin/gprof be disconnected from the build? -- Steve ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
Re: Profiling code execution on amd64?
I would suggest using hwpmc for profiling: # kldload hwpmc # pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration # pmcstat -R /tmp/samples.out -G /tmp/penetration.txt You can also get pmcstat to generate gprof-compatible output with -g, but I never use the mode so I'm really not sure what it gives you. I think that you have to run gprof on the output or something, but don't hold me to that. ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
Re: Profiling code execution on amd64?
On Thu, Jan 13, 2011 at 10:08:30PM -0500, Ryan Stone wrote: I would suggest using hwpmc for profiling: # kldload hwpmc # pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration # pmcstat -R /tmp/samples.out -G /tmp/penetration.txt You can also get pmcstat to generate gprof-compatible output with -g, but I never use the mode so I'm really not sure what it gives you. I think that you have to run gprof on the output or something, but don't hold me to that. Thanks. I'll give it a try, but my initial attempt seems to indicate that one needs to be root to use hwpmc. laptop:kargl[210] pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration pmcstat: ERROR: Cannot allocate system-mode pmc with specification unhalted-cycles: Operation not permitted -- Steve ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to freebsd-current-unsubscr...@freebsd.org
