Date: Mon, 29 Dec 2008 16:16:44 -0800 From: Yuri <yuri@rawbw.com> To: Christian Weisgerber <naddy@mips.inka.de> Cc: freebsd-hackers@freebsd.org Subject: Re: lzo2 shows insane speed gap Message-ID: <4959686C.7010009@rawbw.com> In-Reply-To: <gjbf7c$hbm$1@lorvorc.mips.inka.de> References: <gjbf7c$hbm$1@lorvorc.mips.inka.de>
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Christian Weisgerber wrote: > My best guess at this time is that lzo2 somehow manages to induce > crazy cache thrashing on some CPU models. > > Ideas and explanations welcome Try running single command that is different on different machines under valgrind (callgrind) on these machines and see that at least number of instructions executed is the same. Lzo2 documentation says that there are a lot of algorithms implemented. It might be choosing the algorithm based on the CPU and the choice it's making might be bad. Yuri
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