What if most I/O are asynchronous writes and handled by a background process (e.g. SoftUpdate syncer daemon or a special kernel daemon), then I guess the wait should have something to do with memory or buffer. But I do not know to to confirm this. Maybe some profiling or instrumentation (too much work?) will help.
-Zhihui On Wed, 15 May 2002, Alfred Perlstein wrote: > * Zhihui Zhang <[EMAIL PROTECTED]> [020515 10:33] wrote: > > > > Basically I have a program that does a lot of I/O and alloctes/frees a lot > > of memory. The time command gives result like this: > > > > 6.239u 19.329s 7:59.76 5.3% 310+775k 3993+246io 7pf+0w > > > > I want to know why CPU is running only 5.3% of the total time. I just > > want know how long it is waiting for memory and how long it is waiting for > > I/O. No other process is running at the same time. > > When not condending against other processes, almost all time not > spent on CPU is waiting for IO. > > -Alfred > > To Unsubscribe: send mail to [EMAIL PROTECTED] > with "unsubscribe freebsd-hackers" in the body of the message > To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
