Re: Digging in the (linux) swap file
On Thu, Jul 17, 2003 at 11:14:16PM +0100, Steve Keay wrote:
On Thu, Jul 17, 2003 at 06:55:59PM +0100, Paul Makepeace wrote:
I don't think the kernel makes any per-process statistics visible.
there's a bunch of numbers in /proc/PID/{maps,stat,statm,status}
That might tell you something. I'm afraid i lost interest before
finding out what the numbers meant.
--
Chris Benson
Re: Digging in the (linux) swap file
Perhaps the Proc::ProcessTable module may be of some use? http://search.cpan.org/author/DURIST/Proc-ProcessTable-0.38/ProcessTable.pm Dan
Digging in the (linux) swap file
Is anyone aware of tools that will show what processes, and what in those processes are using the swap -- e.g. the data paged out? I found nothing on freshmeat or google. There seem, funnily enough, to be plenty of such tools for Windows. I'm curious since I have about 180MB of swap used and it's been gradually creeping up over the months (versus apache which I have to regularly restart). ** Trying to create another swap file, cfdisk can't re-read the partition table, neither will blockdev --rereadpt (there's only been an addition into the Extended partition). Is there some way for it to force a re-read to update /proc/partitions so I can mkswap? The machine's remote not easily rebootable or single-user-mode-able (the obvious answers). # swapon /dev/sda10 swapon: /dev/sda10: No such device or address # blockdev --rereadpt /dev/sda BLKRRPART: Device or resource busy # Paul PS dd if=/dev/swap | strings revealed an awful lot of perl module names. A cpan process running since January was using 35MB RSS+40MB swap... -- Paul Makepeace ... http://paulm.com/ What is the cat doing on my lap? Listen to the wind. -- http://paulm.com/toys/surrealism/
Re: Digging in the (linux) swap file
Paul Makepeace said: Is anyone aware of tools that will show what processes, and what in those processes are using the swap -- e.g. the data paged out? top and ps show you what processes are using swap. particularly, in the STAT column, the W means that the process is sawpped out, except for kernel processes. it will also have the command printed in parentheses. according to top(1): STAT The state of the task is shown here. The state is either S for sleeping, D for uninterruptible sleep, R for running, Z for zom#8208; bies, or T for stopped or traced. These states are modified by trailing for a process with negative nice value, N for a process with positive nice value, W for a swapped out process (this does not work correctly for kernel processes). COMMAND The tasks command name, which will be truncated if it is too long to be displayed on one line. Tasks in memory will have a full command line, but swapped#8208;out tasks will only have the name of the program in parentheses (for example, (getty)). as for picking apart what parts are in the swap, i dunno. it's just a guess, but i would wager that you could see old data in the swap partition, unless there have been security-minded wiping algorithms put in. -- muppet scott at asofyet dot org
Re: Digging in the (linux) swap file
On Thu, Jul 17, 2003 at 01:44:22PM -0400, muppet wrote: Is anyone aware of tools that will show what processes, and what in those processes are using the swap -- e.g. the data paged out? top and ps show you what processes are using swap. particularly, in the STAT There's a critical difference between swapped out and paged out. Swapped means the whole process is languishing whereas paged out just means some portion of the process is there. It's quite rare for processes (IME) to get completely swapped out. Generally it's an indication a program is some system-related like bdflush, or isn't being used at all (so kill it). I'm interested in which processes have _anything_ paged, and which pages. I'm hoping this will give some clue as to what's gradually using up the memory, and even possibly help debug apache's constant bloating without anything more invasive. as for picking apart what parts are in the swap, i dunno. it's just a guess, but i would wager that you could see old data in the swap partition, unless there have been security-minded wiping algorithms put in. Indeed. Paul -- Paul Makepeace ... http://paulm.com/ If this website is shit, I am not the pope, then stones would sing and pebbles would dance. -- http://paulm.com/toys/surrealism/
Re: Digging in the (linux) swap file
On Thu, Jul 17, 2003 at 06:55:59PM +0100, Paul Makepeace wrote: Is anyone aware of tools that will show what processes, and what in those processes are using the swap -- e.g. the data paged out? If the machine is not thrashing (i.e. lots of i/o to the swapfile) then perhaps the processes with large OT (size) but much smaller RSS are candidates? I don't think the kernel makes any per-process statistics visible.
