Date: Fri, 11 Oct 2013 11:40:50 +0800 From: Julian Elischer <julian@elischer.org> To: Ivan Voras <ivoras@freebsd.org> Cc: freebsd-performance@freebsd.org, David Wolfskill <david@catwhisker.org> Subject: Re: Apparent performance regression 8.3@ -> 8.4@r255966? Message-ID: <52577342.4090801@elischer.org> In-Reply-To: <l36c1u$rur$1@ger.gmane.org> References: <20131007172804.GA7641@albert.catwhisker.org> <l36c1u$rur$1@ger.gmane.org>
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On 10/10/13 10:02 PM, Ivan Voras wrote: > On 07/10/2013 19:28, David Wolfskill wrote:> At work, we have a bunch of > machines that developers use to build some >> software. The machines presently run FreeBSD/amd64 8.3-STABLE @rxxxxxx >> (with a few local patches, which have since been committed to stable/8), >> and the software is built within a 32-bit jail. >> >> The hardware includes 2 packages of 6 physical cores each @3.47GHz >> (Intel X5690); SMT is enabled (so the scheduler sees hw.ncpu == >> 24). The memory on the machines was recently increased from 6GB >> to 96GB. >> >> I am trying to set up a replacement host environment on my test machine; >> the current environment there is FreeBSD/amd64 8.4-STABLE @r255966; this >> environment achieves a couple of objectives: >> >> * It has no local patches. >> * The known problems (e.g., with mfiutil failing to report battery >> status accurately) are believed to be addressed appropriately. >> >> However: when I do comparison software builds, the new environment is >> taking about 12% longer to perform the same work (comparing against a >> fair sample of the deployed machines): > So, the test machine is exactly the same as the old machines? Does the > hardware upgrade coincide with 8.4-STABLE upgrade? > > At a guess, you also might be hitting a problem with either NUMA (which > would mean the difference you encountered is pretty much random, > depending on how the memory from your processes was allocated), or a > generic scheduler issue (IIRC, FreeBSD 9 series was found to be much > more scalable for > 16 CPUs). > > Just a thought - you *could* set up an 8-STABLE jail in a 9-STABLE > environment if you need the 8-STABLE libraries for your software. > > > OR, take the new kernel and use it to boot the old system then compare times.
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