From: Yaoping R. <yr...@cs...> - 2004-04-26 18:46:05
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Hi, Last week I asked about a question about the results I got by monitoring Apache web server using Oprofile. What I noticed was that all events, not only GLOBAL_POWER_EVENTS, are significantly smaller on a busier system than on a system having less workload demand. The events I monitored are: GLOBAL_POWER_EVENTS ITLB_REFERENCE (ITLB miss) MEMORY_CANCEL MEMORY_COMPLETE INSTR_RETIRED UOPS_RETIRED RETIRED_MISPRED_BRANCH_TYPE RETIRED_BRANCH_TYPE With the same server configuration, I setup client requesting a single file of 1KB, with a request rate of 300 requests/second, and 100 requests/second. While with 300 requests/second, I got much less counts of all the events. E.g., the number of GLOBAL_POWER_EVENTS is 156529 x 1e6 with 100 requests/second, and is 5188 x 1e6 with 300 requests/second. The number of INSTR_RETIRED is 2491084 x 1e5 with 100 requests/second, and is 84871 x 1e5 with 300 requests/second. I am also using "idle=poll" as one of the boot options, but didn't really see idle_poll, and it didn't change the shape of the results. I believe there's something I missed but couldn't figure out what. Here's the settings I am using: pcontrol --event=GLOBAL_POWER_EVENTS:1000000:0x01 \ ... --vmlinux=/home/linux-2.6.5/vmlinux opcontrol --reset; opcontrol --start TESTS: CLIENT_RUNNING FOR 5 MINUTES opcontrol --dump; opcontrol --stop opreport event:GLOBAL_POWER_EVENTS I was wondering if the scheduling has any delay or interrupt masking feature on Oprofile but the manual says that the counter overflow delivery mode is NMI. So I assume the delay wont' cause such a discrepancy. Thanks for any suggestion - Yaoping |