Re: total memory of children processes

[Martin Pala]

I'm sorry - i have access to linux only machines since i'm on civil service.

Martin

Jan-Henrik Haukeland wrote:

> Christian, do you thing you can you fix this? and if you can, will you
> be able to fix it before early next week?
>
> Does anyone have access to Solaris and can check if this problem occur
> there also?
>
>
>
> Martin Pala <address@hidden> writes:
>
>  
>
> > I see the same problem on my station too:
> >
> > unicorn:~/cvs/monit# ps -leaf
> > F S UID        PID  PPID  C PRI  NI ADDR SZ WCHAN  STIME TTY
> > TIME CMD
> > 1 S root      4890     1  0  69   0 -  2604 rt_sig 18:23 ?
> > 00:00:00 /usr/sbin/slapd
> > 1 S root      4891  4890  0  69   0 -  2604 poll   18:23 ?
> > 00:00:00 /usr/sbin/slapd
> > 1 S root      4892  4891  0  69   0 -  2604 select 18:23 ?
> > 00:00:00 /usr/sbin/slapd
> > 1 S root      4913  4891  0  69   0 -  2604 rt_sig 18:24 ?
> > 00:00:00 /usr/sbin/slapd
> >
> > unicorn:~/cvs/monit# ./monit -c /etc/monitrc status
> > Process 'slapd' is running with pid [4890]
> >        Uptime: 3m  CPU: 0.0% Memory w/o children: 0.8% [2604kB]
> >        Children: 3 Memory w/ children: 3.2% [10416kB]
> >        Monitoring status: monitored
> >
> > As you can see, the reported size is sum of RSS off all threads
> > (4*2604=10416). This is not correct result, because 2604kB is memory
> > shared by threads (LinuxThreads reports each thread with its PID and
> > size, but the memory is shared).
> >
> >
> > Note: this is not related to /proc/kcore patch - it only replaced
> > method for available memory detection (instead of kcore size it is
> > read from /proc/meminfo - the result is the same) => this is
> > standalone problem (bug).
> >
> > Martin
> >
> >
> > Arkadiusz Miskiewicz wrote:
> >
> >    
> >
> > > Hi,
> > >
> > > Total memory of children processes seems miscalculated:
> > > Event: total mem amount of 12193680kB matches resource limit [total
> > > mem amount>512001kB]
> > >
> > > ok but this machine has only 512MB ram and 2GB of swap.
> > >
> > > The problem seems be that only rss (resident set size) value is
> > > used. rss also includes memory shared between processes.
> > >
> > > IMO algoritm to calculate total mem amount should looke like:
> > >
> > > rss of parent + (rss of first child - shared mem, rss of second
> > > chold - shared mem and so on). It's still not perfect because we
> > > don't know between which processes that memory is shared but it's
> > > much better than adding whole rss.
> > >
> > > shared memory can be found in /proc/$pid/statm.
> > >
> > > On my server for httpd proces it's:
> > > address@hidden root]# pmap -x 22746 |less
> > > 22746:   httpd -4
> > > Address       kB Resident Shared Private Permissions       Name
> > > 00110000      80       -       0      80 read/exec         ld-2.2.5.so
> > > 00124000       4       -       0       4 read/write        ld-2.2.5.so
> > > 00125000       8       -       0       8 read/write         [ anon ]
> > > 00128000       4       -       0       4 read/exec         mod_asis.so
> > > [...]
> > > 01142000     980       -     980       0 read/write        mod_jk2.shm
> > > 01237000     980       -     980       0 read/write        mod_jk2.shm
> > > 0132c000     508       -     508       0 read/write
> > > SYSV00000000 (deleted)
> > > 013ab000     364       -     364       0 read/write
> > > SYSV00000000 (deleted)
> > > 08048000     212       -       0     212 read/exec         httpd
> > > 0807d000      32       -       0      32 read/write        httpd
> > > 08085000   63820       -       0   63820 read/write/exec    [ anon ]
> > > 40000000   32768       -   32768       0 read/write
> > > SYSV00000000 (deleted)
> > > 42000000   32768       -   32768       0 read/write
> > > SYSV00000000 (deleted)
> > > bfff5000      44       -       0      44 read/write/exec    [ anon ]
> > > --------  ------  ------  ------  ------
> > > total kB  148912       -   71360   77552
> > >
> > > so almost half of memory used by this process is shared between
> > > httpd (and other) processes...
> > >
> > > Comments?
> > >
> > >      
> >
> >
> > _______________________________________________
> > monit-dev mailing list
> > address@hidden
> > http://mail.nongnu.org/mailman/listinfo/monit-dev
> >
> >    
>
>