Date: Wed, 11 Jul 2007 18:19:30 +0100 (BST) From: Robert Watson <rwatson@FreeBSD.org> To: Girish Motwani <girish.motwani@gmail.com> Cc: freebsd-smp@freebsd.org Subject: Re: kgmon on multiprocessors Message-ID: <20070711181520.R68820@fledge.watson.org> In-Reply-To: <2779e6080707020843g55be2546w722b08a2023d016a@mail.gmail.com> References: <2779e6080707020843g55be2546w722b08a2023d016a@mail.gmail.com>
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On Mon, 2 Jul 2007, Girish Motwani wrote: > Does the kernel profiling tool kgmon give accurate information on > multiprocessor systems ? Or is there some other tool for SMP systems ? I > tried looking up the archives for information on this, but could not find > any. Girish-- Take a look at hwpmc(4), pmccontrol(8), and pmcstat(8). These allow you to do kernel-only or systemic samplic using performance monitoring counters, including looking at CPU time, cache misses, instructions retired, etc. I posted a sixty second howto here: http://lists.freebsd.org/pipermail/freebsd-current/2006-February/061096.html Among other things, you can generate gprof output from PMC; right now, that's without full stack traces (and hence callgraphs), but Joseph Koshy has work in P4 implementing stack trace support. I imagine this will go in after the 7.0 freeze lets up. Robert N M Watson Computer Laboratory University of Cambridge
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