Subject: Re: increasing NMBCLUSTERS
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Chuck Silvers <chuq@chuq.com>
List: tech-net
Date: 09/29/2005 07:59:25
On Thu, Sep 29, 2005 at 04:45:42PM +0200, Manuel Bouyer wrote:
> On Thu, Sep 29, 2005 at 07:25:44AM -0700, Chuck Silvers wrote:
> > I was just looking at a similar problem on john klos's cobalt box last night:
> > 
> > Name        Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
> > mbpl         256  2030774    0  2013827  2924  1691  1233  1321     1   inf    0
> > mclpl       2048   429969 5987311 413585 40542 32346 8196  8196     4  8192    4
> > 
> > # netstat -m
> > 16540 mbufs in use:
> >         16538 mbufs allocated to data
> >         2 mbufs allocated to packet headers
> > 6001641 calls to protocol drain routines
> 
> This time the number of mclpl used matches the number of mbufs:
> 429969 - 413585 = 16384 (this more or less matches the 16540 mbufs in use).

what about the non-cluster mbufs?  there are many of those too.


> > definitely a leak somewhere.  this case was on 2.1_RC3.
> > we have a dump if anyone wants to look at it.
> 
> Can you do a netstat -a on this dump, and look at the sockets send and receive
> queues ? It's also possibles that these mbufs are used for socket queues
> that have problems to drain. I've seen this happens on web servers talking
> with clients behind a broken DSL setup (pmtu blackhole).

that shows only one TCP connection in the dump, and it has nothing in
its send or receive queues.

-Chuck