On Thu, 1 Dec 2011 10:12:37 +0200, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > On Thu, Dec 01, 2011 at 12:58:59PM +1030, Rusty Russell wrote: > > On Thu, 1 Dec 2011 01:13:07 +0200, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > > > For x86, stores into memory are ordered. So I think that yes, smp_XXX > > > can be selected at compile time. > > > > > > So let's forget the virtio strangeness for a minute, > > > > Hmm, we got away with light barriers because we knew we were not > > *really* talking to a device. But now with virtio-mmio, turns out we > > are :) > > You think virtio-mmio this issue too? It's reported on remoteproc... I think any non-virtual, non-PCI device has to worry about it. Perhaps all virtio-mmio are virtual (at this point). I'm tempted to say we want permission from the device to do relaxed barriers (so I don't have to worry about it!) > > I'm really tempted to revert d57ed95 for 3.2, and we can revisit this > > optimization later if it proves worthwhile. > > Generally it does seem the best we can do for 3.2. > > Given it's rc3, I'd be a bit wary of introducing regressions - I'll try > to find some real setups (as in - not my laptop) to run some benchmarks > on, to verify there's no major problem. > I hope I can report on this in about a week from now - want to hold onto this meanwhile? Yep, no huge hurry. Thanks! Cheers, Rusty. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
