RE: Linux Memory Accounting

From: Matthew Zito <mzito_at_gridapp.com>
Date: Mon, 2 Oct 2006 17:13:33 -0400
Message-ID: <C0A5E31718FC064A91E9FD7BE2F081B178B852@exchange.gridapp.com>

 

Shared memory shows up in the RSS of each process....so I suppose you could do complicated math surrounding subtracting out the SGA for all processes that attach therein, and then add it up....  

Matt

---

        From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Jared Still

	Sent: Monday, October 02, 2006 5:04 PM
	To: kevinc_at_polyserve.com
	Cc: Oracle-L Freelists
	Subject: Re: Linux Memory Accounting
	
	
	Thanks, though I think you knew what I meant. :)
	
	To be more precise in what I am asking:
	--------------------------------------
	
	According to the ps man page:
	
	rss            RSS         resident set size, the non-swapped
physical memory that a task has used (in kiloBytes). 
	                           (alias rssize, rsz).
	
	What's interesting is that summing RSS for all Oracle processes 
	on the server in question (RH ES 4 64 Bit) yield 25 gig of RAM.
	
	The server has only 12 gig of RAM.
	
	Here's the ps command:
	
	ps -fywluoracle  | awk  '{ mem=mem+$8 } END{ mem=mem*1024; print

"bytes: ", mem}'         

        My question is: Does someone here know what is really being reported by RSS?         

        Or is it just untrustworthy?         

	-- 
	Jared Still
	Certifiable Oracle DBA and Part Time Perl Evangelist
	
	
	Sample output
	
	[root_at_ordb02 bin]# ps -fywluoracle  | head
	S UID        PID  PPID  C PRI  NI  RSS    SZ WCHAN  STIME TTY
TIME CMD
	S oracle   23792     1  0  76   0 17196 135561 -    Sep04 ?
00:01:27 ora_pmon_pr02
	S oracle   23794     1  0  76   0 15340 135266 -    Sep04 ?
00:00:14 ora_psp0_pr02
	S oracle   23796     1  0  76   0 15408 135266 -    Sep04 ?
00:00:00 ora_mman_pr02 
	S oracle   23798     1  0  76   0 120164 147379 -   Sep04 ?
00:15:59 ora_dbw0_pr02
	S oracle   23800     1  0  76   0 24016 139159 -    Sep04 ?
00:14:57 ora_lgwr_pr02
	S oracle   23802     1  0  76   0 27228 135923 -    Sep04 ?
00:03:47 ora_ckpt_pr02
	S oracle   23804     1  0  76   0 239228 135937 -   Sep04 ?

00:03:41 ora_smon_pr02                                    

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Received on Mon Oct 02 2006 - 16:13:33 CDT