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Re: maxchannel/maxring

On Mon, Feb 05, 2001 at 05:22:59PM +0300, Eugene Crosser wrote:
> Matti,
> am I right that the maximum number of children of scheduler is still
> limited by the maximum number of stdio filehandles?  If so, this is
> quite unfortunate and becoming the bottleneck here.  The computers are
> powerful enough to run several thousands of processes, but deliveries
> are "waiting for thread slot" if there are many distinct remote
> destinations.  Typical picture:
> root@ajax2:/usr/local/sbin/# mailq -QQ
> smtp/*/0
>         Threads:  619 Msgs: 15075 Procs: 150 Idle:   0 Plim: 150 Flim: 150
> Tlim: 1
> I tried to blindly increase maxchannel/maxring beyond 255 and the scheduler
> first started as many agents as I asked but then got crasy (stopped
> responding to mailq command).
> Does sfio have 255 limitation removed?  Does the scheduler still use
> stdio rather than sfio?

	Scheduler uses sfio to remove this stupid limitation you so
	nicely observe at native Solaris stdio library.

	You need to up the  maxchannel=,  maxta= and maxring= values
	suitably.  "maxta=0" is good value too as it uses systemcalls
	to figure the real ultimate limit on the number of files that
	the scheduler can have open -> the number of child processes.

	... but I have tested only versions less than 1/2 years old
	with huge numbers of FDs in use.

	When I find some BUGs, I try to log them into:
	perhaps this is mentioned in relation to your running version ?

> Eugene

/Matti Aarnio	<mea@nic.funet.fi>