patch for HEAD and SAMBA_2_2

Scott Moomaw scott at
Tue Sep 25 10:37:16 GMT 2001

When the load average begins to climb, have you looked at the number of
smbd processes that exist?  I have seen several occasions where the system
under heavy load starts spawning new smbd processes at a high rate.  It is
like some timeout is happening so a new process is being spawned.  Given a
short amount of time in this condition, the server can spawn 1000s of new
smbd processes exacerbating this problem to the point that killing samba
is the only solution.


On Tue, 25 Sep 2001, David Lee wrote:

> We have been hitting performance problems with 2.2.1a, especially the
> "fcntl loop" problem, which causes occasional processes to gobble CPU.
> By arrangement with Jeremy Allison and Gerry Carter, we are now running
> SAMBA_2_2 (2.2.2-pre) as of the weekend: this is looking good w.r.t. to
> fcntl problem.
> But with both (2.2.1a, 2.2.2-pre) we are experiencing another problem,
> which I had at first attributed to a side-effect of fcntl, but am now less
> sure.
> We routine run several hundred concurrent smbd processes as routine.  But
> every few hours, the load average of the server (Sun E450, Solaris 8)
> will suddenly start to rise horribly: the only solution is "pkill smbd".
> This set me wondering about what a "dormant" smbd does.  We know that the
> central "process.c" loop will awake every 60 seconds, regardless.  Thus
> with, say, 300 smb processes, even all "doing nothing", there will be at
> least 5 per second actually doing something ("in background").
> The big question is:  anyone else seen this behaviour?
> My modest contribution is the attached patch to eliminate some unnecessary
> work which sometimes gets done "in background".  Basically, there are
> occasional background calls to "reopen_logs()" in "lib/debug.c" which
> do a double call of "lp_logfile()" and all that it entails.  The patch
> reduces that to a single call.
> The patch is against SAMBA_2_2 but almost certainly applies to HEAD too.
> (I don't think it completely solves my problem, but it might help it a
> little...)
> --
> :  David Lee                                I.T. Service          :
> :  Systems Programmer                       Computer Centre       :
> :                                           University of Durham  :
> :            South Road            :
> :                                           Durham                :
> :  Phone: +44 191 374 2882                  U.K.                  :

 Scott Moomaw, Network Administrator              Scott at
 Bridgewater College, IT Center
 Bridgewater, VA  22812
 Phone (540) 828 - 8000  x5437              FAX:  (540) 828 - 5493

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