On Wed, 03 Mar 2004 00:34:37 +0800 "Zhang Weiwu" <[EMAIL PROTECTED]> probably wrote:
> Today I did't experiment on {rt|id}prio(1), just to be interesting. I am > trying to understand FreeBSD priority mechenism. IMHO realtime/idle > priority only starvs processes when there is no cpu resource at all. > > To test, I run mpg321 on realtime priority 3, run ppp on realtime priority > 4, a little lower than mpg321, and scp over the ppp tunnel on normal > priority. > > Top(1) shows an average about: > 55.2% user, 0.0% nice, 21.5% system, 12.2% interrupt, 11.1% idle > * mpg321 takes average about 70%; > * ppp is seriously slowed down, it takes about 1.5% (normally 17% on full > speed); > * sshd almost starves; it takes 0.00% (normally 2%) and only transfer > several bytes once several minutes; the otherside scp prompts "stalled". sshd doesn't starve CPU, I guess; as you reach it through ppp, and ppp gets slow, sshd does, too. > I'm the kind of newbie think 11.1% idle cpu time to be free cpu resource, > because I don't have idle process. I wish to know why, as there are still > 11.1% free cpu resource, ppp and sshd doesn't get this share? The most frequent cause is that they don't need the CPU so much as something else, like disk I/O, etc. Could you please post the whole output of top (and a snapshot of systat -vmstat, for example)? > Just to be curious. Thank you. FWIW, splay uses <30% of a P150:) -- DoubleF A jury consists of 12 persons chosen to decide who has the better lawyer. -- Robert Frost
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