From: Zeev Fisher (zeevf@galileo.co.il)
Date: Mon Jul 01 2002 - 12:41:05 EDT
Hi,
I don't quite understand the order of execution on an SMP systems and
some issues of LWP
I have a multithreaded application ( 3rd party ) which i inspect and see
that each monitoring interval it runs on a different CPU although it's
known
that it's best to keep a process running on the same processor ( keep
"warm" cache )
Another thing is that the number of LWP for a given process is changing
from time to time during the process execution - ??
For example , under V880 with 4 processors , i have the following case :
in a specific minute :
prstat -L :
root@galileo219 > /bin/ps -elcL
...
...
...
...
8 R 686 524 521 1 TS 50 ? 248522 pts/2
194:40 calibre6
8 S 686 524 521 2 TS 58 ? 248522 ? pts/2
0:00 calibre6
8 S 686 524 521 3 TS 58 ? 248522 ? pts/2
12:05 calibre6
8 O 686 524 521 4 TS 50 ? 248522 pts/2
190:23 calibre6
8 S 686 524 521 5 TS 58 ? 248522 ? pts/2
34:10 calibre6
8 O 686 524 521 6 TS 0 ? 248522 pts/2
190:40 calibre6
8 S 686 524 521 22 TS 58 ? 248522 ? pts/2
0:00 calibre6
8 O 686 524 521 12 TS 50 ? 248522 pts/2
166:37 calibre6
8 S 686 524 521 23 TS 58 ? 248522 ? pts/2
0:00 calibre6
8 S 686 524 521 24 TS 58 ? 248522 ? pts/2
0:00 calibre6
8 S 686 524 521 25 TS 58 ? 248522 ? pts/2
0:00 calibre6
8 S 686 524 521 26 TS 58 ? 248522 ? pts/2
0:00 calibre6
8 S 686 524 521 27 TS 58 ? 248522 ? pts/2
0:00 calibre6
13 LWP of the same process id ( 524 ).
prstat -L on 1 moment : ( paste of the relevent section )
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/LWPID
524 israelb 1994M 1976M run 10 0 2:48.54 22% calibre64/12
524 israelb 1994M 1976M cpu2 10 0 3:16.56 22% calibre64/1
524 israelb 1994M 1976M cpu0 10 0 3:12.38 22% calibre64/4
524 israelb 1994M 1976M cpu1 20 0 3:12.57 22% calibre64/6
524 israelb 1994M 1976M sleep 48 0 0:34.13 0.6% calibre64/5
After another moment :
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/LWPID
524 israelb 1994M 1976M cpu0 0 0 3:17.25 17% calibre64/1
524 israelb 1994M 1976M cpu1 0 0 3:13.06 17% calibre64/4
524 israelb 1994M 1976M run 0 0 2:49.22 17% calibre64/12
524 israelb 1994M 1976M cpu3 0 0 3:13.25 17% calibre64/6
524 israelb 1994M 1976M sleep 30 0 0:34.19 6.2% calibre64/5
We see that for example LWP 1 was running on cpu2 and on the other
moment it's running on CPU0
Another thing is that on a specific moment i see only 3 processes
running and not 4 ( 3 running and 1 in the run state waiting to run ) - ?
Thanks in advance for your answer.
I will summarize.
-- Zeev Fisher - Unix System Administrator Galileo Technology Ltd - A Marvell Company Moshav Manof, D.N. Misgav 20184, ISRAEL Email - zeevf@galileo.co.il Tel - + 972 4 8225046 ext. 1402 Cell - + 972 54 995402 Fax - + 972 4 8326420 WWW Page: http://www.marvell.com ------------------------------------------------------------------------ This message may contain confidential, proprietary or legally privileged information. The information is intended only for the use of the individual or entity named above. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by telephone, or by e-mail and delete the message from your computer. _______________________________________________ sunmanagers mailing list sunmanagers@sunmanagers.org http://www.sunmanagers.org/mailman/listinfo/sunmanagers
This archive was generated by hypermail 2.1.7 : Wed Apr 09 2008 - 23:24:32 EDT