Date: Mon, 17 Jan 2011 09:45:44 +0100 From: Fabien Thomas <fabien.thomas@netasq.com> To: Garrett Cooper <gcooper@FreeBSD.org> Cc: George Neville-Neil <gnn@freebsd.org>, freebsd-current@freebsd.org, Ryan Stone <rysto32@gmail.com>, Steve Kargl <sgk@troutmask.apl.washington.edu> Subject: Re: Profiling code execution on amd64? Message-ID: <88A95F5C-FDE9-425C-AC1B-D90B66A51B9C@netasq.com> In-Reply-To: <AANLkTikYk0MP=gBnxz3%2BkjF_nRKyqQQO5VK2wUUnRQyM@mail.gmail.com> References: <20110113171139.GA32250@troutmask.apl.washington.edu> <AANLkTi=C4L9fn7q8PfJgY=8c24BQnZTC9s7BubsrUYxv@mail.gmail.com> <20110114040549.GA36430@troutmask.apl.washington.edu> <1D4725BB-0A0A-44FB-9FF1-23969C469AA6@freebsd.org> <20110115061023.GA41547@troutmask.apl.washington.edu> <AANLkTikYk0MP=gBnxz3%2BkjF_nRKyqQQO5VK2wUUnRQyM@mail.gmail.com>
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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=20 Fabien > On Fri, Jan 14, 2011 at 10:10 PM, Steve Kargl > <sgk@troutmask.apl.washington.edu> wrote: >> On Fri, Jan 14, 2011 at 03:40:46PM -0500, George Neville-Neil wrote: >>>=20 >>> On Jan 13, 2011, at 23:05 , Steve Kargl wrote: >>>=20 >>>> On Thu, Jan 13, 2011 at 10:08:30PM -0500, Ryan Stone wrote: >>>>> I would suggest using hwpmc for profiling: >>>>>=20 >>>>> # kldload hwpmc >>>>> # pmcstat -S unhalted-cycles -O /tmp/samples.out ../penetration >>>>> # pmcstat -R /tmp/samples.out -G /tmp/penetration.txt >>>>>=20 >>>>>=20 >>>>> 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. >>>>=20 >>>>=20 >>>> Thanks. I'll give it a try, but my initial attempt seems to >>>> indicate that one needs to be root to use hwpmc. >>>>=20 >>>> 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 >>>>=20 >>>=20 >>> You only need to be root to profile the kernel or someone else's = process. >>>=20 >>> This tutorial might help: >>>=20 >>> www.dcbsdcon.org/speakers/slides/neville-neil_dcbsdcon2009.pdf >>>=20 >>=20 >> Thanks. I'll look at the tutorial. Meanwhile, should gprof >> be removed from the base system because it appears broken? >=20 > 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-unsubscribe@freebsd.org"
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