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.
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