From: Peter W. <wp...@us...> - 2001-10-01 22:42:31
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In August I reported that there was a 40% performance gain on a heavy database workload using Jens Axboe's zero-bounce highmem I/O patch and my IPS patch running 2.4.5 on a 4-way machine. This time I want to report the performance gain using the above two patches and Jonathan Lahr's io_request_lock patch running 2.4.6 on an 8-way machine. With Jens' patch and my patch, the total elapsed time for processing the queries was cut by 34%. With the above two patches as the baseline, Jonathan's io_request_lock patch cut the total elapsed time by an additional 36%. The CPU utilization corresponding to the bounce patches was 25% (user), 63% (kernel) and 12% (idle). With Jonathan's patch added, the CPU utilization became 40% (user), 29% (kernel) and 31% (idle). We can see that there was a significant drop in kernel time and an increase in idle time. In addition, I did not detect any system problems using Jonathan's patch during a lengthy period of heavy query processing. Jonathan's io_request_lock patch can be found at http://lse.sourceforge.net/io/. Regards, Peter Wai Yee Peter Wong IBM Linux Technology Center, Performance Analysis email: wp...@us... Office: (512) 838-9272, T/L 678-9272; Fax: (512) 838-4663 |