On 4/23/06, Tao Chen <[EMAIL PROTECTED]> wrote: > On 4/23/06, Sh <[EMAIL PROTECTED]> wrote: > > I have some questions about the prstat utility output > > For example if I do prstat -a: > > ---cut---- > > NPROC USERNAME SIZE RSS MEMORY TIME CPU > > 40 wraith 983M 399M 79% 0:48:04 15% > > 48 root 201M 90M 18% > 0:00:28 0,0% > > 2 daemon 10M 2856K 0,6% 0:00:00 0,0% > > 5 nobody 42M 6468K 1,3% 0:00:00 0,0% > > > > > > What it meant under 'SIZE' here?Virtual memory size?Real size of RAM > memory is 512 mb > > So what is 983 mb here? > > From manpage: > > SIZE > The total virtual memory size of the process, including all mapped > files and devices ... > > RSS > The resident set size of the process (RSS) ...
The important thing to remember here is that multiple processes can (and usually do) map some of the same pages. The things that fall into the "usually do" category are shared libraries and executables. Nearly everything will have some portion of libc mapped. In the event that wraith is running JDS, a huge amount of the RAM is likely tied up in a bunch of executables mapping libraries like glib, gtk, etc. > *Users who want to get more accurate usage information for capacity > planning should use the -x option to pmap(1) instead.* With this you can look at each process individually to see how much RAM is being used for the stack and heap - these are the places that "normal" processes will chew up the RAM. More sophisticated programs may be using shared memory segments (which are typically shared among several programs) and/or memory mapped files (which may or may not be shared among many programs). Mike -- Mike Gerdts http://mgerdts.blogspot.com/ _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
