On Friday, 9 December 2005 at 8:23:26 +0800, David Xu wrote: > Greg 'groggy' Lehey wrote: > >> I've heard this claim again and again, and I intend to look at it when >> I have time. I find it difficult to believe that this alone could >> explain the sometimes horrendous performance differences (3 to 1) that >> have been reported. >> >> Can somebody tell me: >> >> 1. How many calls there are per second? >> 2. Where they're coming from? This would involve profiling, of >> course. > > You find ktrace result of mysql: > http://people.freebsd.org/~davidxu/mysql/mysql_ktrace.txt > gettimeofday() almost follows every network I/O.
ktrace doesn't give a call graph. We don't know which function is calling it. That's why we need profiling. > Also you can find its I/O size: > http://people.freebsd.org/~davidxu/mysql/iosize.txt Ugh. It would be nice to know what those fds are. > I guess the gettimeofday() call is relevant to mysql's connection > keepalive work, sounds like a very silly method. As you say, that's a guess. We need to find out facts. Greg -- See complete headers for address and phone numbers.
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