Followup to: <20010306000652.A13992@excalibur.research.wombat.ie>
By author: Kenn Humborg <kenn@linux.ie>
In newsgroup: linux.dev.kernel
>
> On Sun, Mar 04, 2001 at 11:41:12PM +0100, Manfred Spraul wrote:
> > >
> > > Does kmalloc() make any guarantees of the alignment of allocated
> > > blocks? Will the returned block always be 4-, 8- or 16-byte
> > > aligned, for example?
> > >
> >
> > 4-byte alignment is guaranteed on 32-bit cpus, 8-byte alignment on
> > 64-bit cpus.
>
> So, to summarise (for 32-bit CPUs):
>
> o Alan Cox & Manfred Spraul say 4-byte alignment is guaranteed.
>
> o If you need larger alignment, you need to alloc a larger space,
> round as necessary, and keep the original pointer for kfree()
>
> Maybe I'll just use get_free_pages, since it's a 64KB chunk that
> I need (and it's only a once-off).
>
It might be worth asking the question if larger blocks are more
aligned?
-hpa
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