Messages in this thread | | | Date | Sun, 16 Mar 2008 01:38:51 -0400 | From | Allan Menezes <> | Subject | HPL benchmarking linux kernel for shared memory performance. |
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Hi, I eliminated in which kernel verion this begins to happen. I am benchmarking a single node with hpl and openmpi beta 1.3 and gotoblas v1.24 for personal noncommercial reasons. I tried a single node with the command $ mpirun -np 1 ./xhpl and with kernel ver 2.6.23.14 i get over 38Gflops but with kernel ver 2.6.23.15 compiling with the same .config i get 7.xx Gflops which is 1/5th that of the other kernel. Keep in mind that only the kernels have changed from kernel.org not any hardware or anything else as all else is same! but the performace drops to 1/5th There is no network involved in this single node quad core intel test but just shared memory. So the shared memory or smp performance of the newer kernels is far far worse than upto 2.6.23.14! Even with 2.6.25.rc5 the performance is degraded! Can you please help me find why this is occurring? Please advise! mY set up Quad core Q6600 intel overclocked stably to 2.88 GHZ , 6 gig ddr2 800 mhz dual channel ram, Allan Menezes
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