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From: Andrew Morton <akpm@digeo.com>
To: Tim Hockin <thockin@hockin.org>
Cc: Tim Hockin <thockin@sun.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [BK PATCH 1/2] Remove NGROUPS hardlimit (resend w/o qsort)
Date: Thu, 14 Nov 2002 18:41:47 -0800	[thread overview]
Message-ID: <3DD45EEB.4E4F170@digeo.com> (raw)
In-Reply-To: 200211150233.gAF2XQv15588@www.hockin.org

Tim Hockin wrote:
> 
> > 10,000 bits isn't much.  Maybe:
> 
> That's 10000 USED bits.  Remember groups are non-contiguously allocated.  If
> a task is a member of just groups 32767 and 65535, you'll get one bit per
> page used, and when they call getgroups() you need to pull it apart and
> return an array of gid_t.
> 

Well that's what I was asking.

What is the maximum group ID?  0xffffffff?

In that case a radix tree _might_ suit.  All you need to put in the
node is a (void *)1 or (void *)0.  But it won't be very space-efficient
for really sparse groups.

  reply	other threads:[~2002-11-15  2:35 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <mailman.1037316781.6599.linux-kernel2news@redhat.com>
2002-11-15  0:06 ` [BK PATCH 1/2] Remove NGROUPS hardlimit (resend w/o qsort) Pete Zaitcev
2002-11-15  0:14   ` Tim Hockin
2002-11-15  0:31     ` Pete Zaitcev
2002-11-15  0:46       ` Tim Hockin
2002-11-15  1:19         ` William Lee Irwin III
2002-11-15  1:45           ` Pete Zaitcev
2002-11-15  1:53             ` William Lee Irwin III
     [not found]         ` <3DD44742.2DFE4407@digeo.com>
2002-11-15  1:24           ` Tim Hockin
2002-11-15  1:30             ` Andrew Morton
2002-11-15  2:33               ` Tim Hockin
2002-11-15  2:41                 ` Andrew Morton [this message]
2002-11-15 15:13                   ` Alan Cox
2002-11-15  6:00               ` Aaron Lehmann
2002-11-15  1:04       ` Alan Cox
2002-11-15 13:32       ` Frank van Maarseveen
2002-11-14 23:26 Timothy Hockin
2002-11-15 16:30 ` Horst von Brand

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