Messages in this thread | | | Date | Wed, 14 Jan 2004 00:46:11 +0100 | From | Haakon Riiser <> | Subject | Re: Busy-wait delay in qmail 1.03 after upgrading to Linux 2.6 |
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> Output from time: > > real 0m0.309s > user 0m0.011s > sys 0m0.004s
Just wanted to comment on my own data, since I just noticed it myself:
The output from time indicates that the system is _not_ using CPU while delaying, so you might wonder why I said it did. The reason is that I'm using an AfterStep applet (ascpu) to monitor CPU usage, and it appeared to work fine in 2.6. Now, I see that there are differences: For example, another problem I encountered while upgrading to 2.6 was that disk intensive jobs, such as updating the slocate database, made ascpu report 100% CPU usage. I just ran top (procps 2.0.16) beside it, and it reported approximately 10% CPU usage, which is no more than 2.4 used.
I don't know how ascpu measures CPU usage, but it's interesting that it appears to work fine for the most part, while giving _completely_ different results from all other programs (e.g., time, top, ps) in the write-delay case, and other disk related activities.
(For the record, I've never seen ascpu's results differ from top's under Linux 2.4.x.)
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