CedBer, I have seen similar issues on Solaris versions 8 & 9, with no conclusive answer. If you take top and add up all the process CPU usage and use the very summary shown by top for usr and kernel usage, the total of all the processes does not add up to the usr %. I have heard that the latest version of top adds the kernel usage by each process on to the process cpu usage, however the values still do not add up. >From looking at the source code of top, it looks like the summary shown uses an "exponential weighted average" calculation to derive the total usr & kernel cpu usages. That could be the reason for the mismatch. The problem still persists with trying to map the vmstat/sar/iostat usr & ker cpu usage with the sum obtained from top/prstat. fyi...i have seen this on N240 & N440 servers. Does any one have a clue why there the solaris accounting does not add up ?
Thanks, Cherian On Nov 30, 2007 12:47 PM, Eric Saxe <[EMAIL PROTECTED]> wrote: > CedBer wrote: > > If I divide by 8 rather than 4, I have B=1/2*C ! (where B is the sum of > processes %CPU of top an C the usr+sys vmstat value) > > > Are you observing that same discrepancy between prstat and vmstat? > vmstat derives it's statistics from the cpu kstats...whereas prstat > looks at the lwp ps(1) information file in /proc. I'm not sure what top > uses...but I would imagine it looks at /proc as well. > > Thanks, > -Eric > _______________________________________________ > perf-discuss mailing list > perf-discuss@opensolaris.org >
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