Performance, threads question.

From: Grant Schoep <grant_at_storm.com>
Date: Fri, 26 Feb 1999 14:35:11 -0800

We have been having a performance problem on a machine, and I really can't
track down what it is. I am not really familar with the threads output of
vmstat on OSF1 either, and I think that is showing me some that is suspect.
Here is a short clip of the output of vmstat on the machine in question.
I cut out the first line since its just averages.

Virtual Memory Statistics: (pagesize = 8192)
  procs memory pages intr cpu
  r w u act free wire fault cow zero react pin pout in sy cs us sy id
  7216 22 17K 502 5240 4545 1301 1501 0 1072 0 519 7K 2K 51 49 0
  7218 22 17K 267 5259 3574 956 1073 0 1236 0 622 7K 2K 54 45 0
  6217 23 17K 510 5242 2536 634 1015 0 516 0 598 8K 2K 57 43 0
  8218 22 17K 126 5260 7678 2514 1944 0 1793 0 604 7K 2K 39 60 0
  5219 23 17K 489 5243 6345 2075 1558 0 1605 0 641 7K 2K 35 65 0

It looks like the w column is sitting around 217 threads.
man pages says this:
  r Number of threads that are running or are runnable.
  w Number of threads waiting interruptibly.
  u Number of threads waiting uninterruptibly.

So the w column is threads wiating interuptibly.
What does this mean?

yes, I see that the CPU idle is free at this point, but its not always like
that, and at many times wheren the CPU idle is sitting at 70, the w column
is always around 200-300.

Basically, I just was wondering if someone could fill me in on what the
three column, r,w,u really mean. I understand the r column. But what is the
difference bewteen interrupitibly and uninterupitibly. Other than both
words sound like they were made up. :>

                -grant


---------------------------------------------------------------------------
Grant Schoep, grant_at_storm.com
System/Network Administrator
L3 Communications Telemetry & Instrumentation
San Jose,CA (408)271-0800, Ext. 135
Received on Fri Feb 26 1999 - 22:41:35 NZDT

This archive was generated by hypermail 2.4.0 : Wed Nov 08 2023 - 11:53:39 NZDT