Messages in this thread | | | Date | Fri, 7 Jul 2006 18:25:22 -0700 (PDT) | From | Christoph Lameter <> | Subject | Re: [RFC 5/8] x86_64 without ZONE_DMA |
| |
On Sat, 8 Jul 2006, Andi Kleen wrote:
> > The savings are not only from the code paths. The VM itself is cleaner and > > the balancing issues are not that troublesome anymore. > > Doesn't help - it has to be fixed anyways for NUMA and other architectures.
Some architectures like ours can run with a single zone since they have DMA that works anywhere. Same thing is true for my machines are home and at work.
> Also in my experience empty zones are not a significant problem for VM > balancing.
The problem is that the zones are not even empty! We keep 16M in some weird ZONE_DMA that barely anyone one uses anymore and add slabs to it that are only used by some confused device drivers.
Also the empty zones are still a problem since they have to be scanned repeatedly (potentially on each allocation). They waste cachelines and result in loops where we could just have straight code. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |