On Thursday July 7 2005 11:46 am, Philippe Troin wrote: > Sheo Shanker Prasad <[EMAIL PROTECTED]> writes: > > I will appreciate your help in eliminating a disturbing wide > > variation (by a factors of 2 to 2.5) in the execution time of a test > > (execution benchmark) program under identical conditions even when > > the machine is freshly started (rebooted) and no other user program > > is running (not even e-mail or Internet browser). > > > > I have a dual Opteron 250 (2.4 GHz) running SuSE 9.3 Pro & Linux > > version 2.6.11.4-21.7-smp ([EMAIL PROTECTED]) (gcc version 3.3.5 > > 20050117 (prerelease) (SUSE Linux)) #1 SMP Thu Jun 2 14:23:14 UTC > > 2005. The motherboard is Tyan Thunder K8W (S2885 ANRF) with AMI BIOS > > > > The machine has 4GB of PC3200 DDR RAM, two dimms on each CPU. > > > > The original machine bought from a vendor about 6 months ago. At > > that time it was running SuSE 9.1 Pro and the execution time for the > > same test program was consistently the same (around 2m 37s +/- a few > > %). Then the mother board failed and the machine went totally > > dead. The vendor then replaced the failed motherboard with a new > > Tyan Thunder K8W and installed the SuSE 9.3. I am not sure whether > > or not the AMI BIOS was also replaced. > > > > When the repaired machine was started, I began to notice the > > disturbing wide variation and the frequect significant slow down of > > the machine as exhibited by the factor of 2 to 2.5 increased > > execution time of the test program as described above. Sometimes it > > would be quite fast (executing at the original 2m 40s) and sometime > > a factor of 2.5 slow, and sometimes with speed in between. > > 8< snip >8
Thanks very much for your taking time to think about my problem. Here are answers to your questions. > > 1. Are you running an i386 kernel or an x86_64 kernel? I think, I am running a x86_64 kernel. I think so, because I had asked the vendor of the machine to install x86_64 and because the file System.map-2.6.11.4-21.7-smp in the /boot directory has an entry: ffffffff804f0000 T x86_64_start_kernel and that directory also contains the gzipped file: symvers-2.6.11.4-21.7-x86_64-smp.gz The operating system is Linux version 2.6.11.4-21.7-smp ([EMAIL PROTECTED]) (gcc version 3.3.5 20050117 (prerelease) (SUSE Linux)) #1 SMP Thu Jun 2 14:23:14 UTC 2005 > > 2. Which BIOS version? The BIOS is AMIBIOS version is 08.00.10 with the build date of 02/11/05 09:44:04 and has the ID: 0AAAA001. > > 3. Is node interleaving enabled in the BIOS? When I go through the BIOS setup, I do not see any choice for the node interleaving ON or OFF. However, I think that the two CPUs (as node0 and node1) are made NUMA aware by default, but I could be quite wrong. Out of ignorance, therefore, the following are the contents of /sys/devices/system/node/node0/numastat & numa_hit 3620274 numa_miss 0 numa_foreign 0 interleave_hit 21903 local_node 3610298agravaited other_node 9976 Similarly, following are the the contents of /sys/devices/system/node/node1/numastat numa_hit 3089426 numa_miss 0 numa_foreign 0 interleave_hit 38355 local_node 3072605 other_node 16821 > > Phil. Thanks again, Phil, and I hope to hear from you soon. -- Best regards. Sheo (Sheo S. Prasad) Creative Research Enterprises 6354 Camino del Lago Pleasanton, CA 94566, USA Voice Phone: (+1) 925 426-9341 Fax Phone: (+1) 925 426-9417 e-mail: [EMAIL PROTECTED] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
