On Fri, Oct 28, 2011 at 10:07:12AM -0700, Dan Magenheimer wrote: > First, there are several companies and several unaffiliated kernel > developers contributing here, building on top of frontswap. I happen > to be spearheading it, and my company is backing me up. (It > might be more appropriate to note that much of the resistance comes > from people of your company... but please let's keep our open-source > developer hats on and have a technical discussion rather than one > which pleases our respective corporate overlords.) Fair enough to want an independent review but I'd be interesting to also know how many of the several companies and unaffiliated kernel developers are contributing to it that aren't using tmem with Xen. Obviously bounce buffers 4k vmexits are still faster than Xen-paravirt-I/O on disk platter... Note, Hugh is working for another company... and they're using cgroups not KVM nor Xen, so I suggests he'd be a fair reviewer from a non-virt standpoint, if he hopefully has the time to weight in. However keep in mind if we'd see something that can allow KVM to run even faster, we'd be quite silly in not taking advantage of it too, to beat our own SPECvirt record. The whole design idea of KVM (unlike Xen) is to reuse the kernel improvements as much as possible so when the guest runs faster the hypervisor also runs faster with the exact same code. Problem a vmexit doing a bounce buffer every 4k doesn't mix well into SPECvirt in my view and that probably is what has kept us from making any attempt to use tmem API anywhere. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>