Re: [patch 3/4] cpu alloc: The allocator

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 03 Oct 2008 10:43:31 +0300 Pekka Enberg <penberg@cs.helsinki.fi> wrote:

> Hi Andrew,
> 
> On Fri, 2008-10-03 at 00:33 -0700, Andrew Morton wrote:
> > > +static void set_map(int start, int length)
> > > +{
> > > +	while (length-- > 0)
> > > +		__set_bit(start++, cpu_alloc_map);
> > > +}
> > 
> > Can we use bitmap_fill() here?
> 
> But bitmap_fill() assumes that the starting offset is aligned to
> unsigned long (which is not the case here), doesn't it?

umm, yeah, the whole bitmap interface is busted from that POV.

> ___On Fri, 2008-10-03 at 00:33 -0700, Andrew Morton wrote:
> > But I'd have though that it would be possible to only allocate the
> > storage for online CPUs.  That would be a pretty significant win for
> > some system configurations?
> 
> Maybe, but then you'd have to deal with CPU hotplug... iik.

Of course.