Re: [BK PATCH 1/2] Remove NGROUPS hardlimit (resend w/o qsort)

Andrew Morton
2002-11-15T02:35:03Z

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.