On Fri, May 11, 2007 at 07:43:50PM -0400, Grok Mogger wrote: > I have a question about the "wa" fields in vmstat, top, and the > like. I and someone else I know have both read a great deal > about its meaning, and have come to two different conclusions. > Here are our interpretations. Could someone please tell me > which interpretation is right? Thanks! > > Interpretation A: > > "wa" reflects time that your cpu is waiting on hard disks and > network. It is basically the same as "idle" time. If your CPU > had more work to do, it could do it. I believe this is the correct interpretation; your machine could still do more work if that work were purely CPU-bound tasks. > So in a situation like > this.... (I'm simplifying the example to get the point across) > > 10%us 10%sy 30%id 50%wa > > The CPU is really truly 80% idle. It's only using 20% of its > capacity, and if it had enough work to fill the remaining 80%, > it could and would. You'd see 100% allocated between us and sy, > and 0% on id and wa. Well, the work it already has that is waiting on IO is still there, so wa is not going to go down to 0%. Cheers, Andy -- http://bitfolk.com/ -- No-nonsense VPS hosting Encrypted mail welcome - keyid 0x604DE5DB
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