On Wed, Jan 12, 2005 at 03:43:44PM -0200, Vinicius wrote:
Mogens Kjaer escreveu:
Vinicius wrote:
...
time yum --help takes: real 0m7.125s
...
Why, please?
Why so long or why so short?
You can do a: strace -t -o/tmp/yum.log yum --help
I see several lines as "open("/usr/lib/python2.3/lib-dynload/yum.so", O_RDONLY|O_LARGEFILE) = -1 ENOENT (No such file or directory)" for example.
Is it relevant?
The open() ENOENT calls are commonly quick. strace has flags that help you time system calls (-tt -r -T).
This open() returns ENOENT.
open("/usr/lib/python23.zip/sitemodule.so",.... <0.000013>
So to me 0.000013 is not relevant to me unless there is a pile of them.
Run it through strace twice in a row with different log files and the additional time information flags then match up the files (vim -d might work) and match the system calls.
Something like... presents me with hints that I think answer the question. # time yum -help .... real 0m2.097s user 0m0.200s sys 0m0.085s # time yum -help .... real 0m0.349s user 0m0.205s sys 0m0.026s
This quickly tells me that a lot of time is being spent waiting on my disk IO. YMMV....
Cool tip.
Did you see the report from John Swartzentruber about the connect and send system calls? They do something?
