Subject: Re: [vserver] Maximum number of Contexts
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Wed, 25 Feb 2009 01:14:40 +0100

On Tue, Feb 24, 2009 at 01:10:05PM -0500, John A. Sullivan III wrote:
> On Tue, 2009-02-24 at 12:27 -0500, John A. Sullivan III wrote:
> > While on the subject of kernel compiles, what exactly is Maximum number
> > of Contexts for? The explanation throws me off when it says "This makes
> > sure that at least this many contexts can be created" when the name says
> > it is the Maximum rather than Minimum.  Thanks - John
> 
> Hmm . . . I don't see this in 2.3.0.36.4.  Was it obsolesced?

it's still there (even in 2.3.0.36.7 :)

config	VSERVER_CONTEXTS
	int	"Maximum number of Contexts (1-65533)"	if EMBEDDED
	range 1 65533
	default "768"	if 64BIT
	default "256"
	help
	  This setting will optimize certain data structures
	  and memory allocations according to the expected
	  maximum.

	  note: this is not a strict upper limit.
----------------------------------------------------------------

I also think that the entry itself makes it quite
clear what the purpose is:

 - embedded systems might not want to waste memory or
   kernel resources for N >> M contexts, especially if
   M is in the single digits
 - it is not a strict upper limit, but if you know you
   are going to run 10000 contexts on this kernel, you'd
   better set it higher than default, or be prepared to
   hit some limit/performance penalty

HTC,
Herbert

> -- 
> John A. Sullivan III
> Open Source Development Corporation
> +1 207-985-7880
> jsullivan@opensourcedevel.com
> 
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