Re: [PATCHv3 0/6] tun zerocopy support

2012-07-22 Thread David Miller
From: "Michael S. Tsirkin" Date: Sun, 22 Jul 2012 01:05:34 +0300 > I agree a small win in CPU use is nothing to write home about, > I don't yet understand why the win is so small - macvtap has zero copy > supported for a while and it has exactly same issues. > I hope adding tun zerocopy support u

Re: [PATCHv3 0/6] tun zerocopy support

2012-07-21 Thread Michael S. Tsirkin
On Fri, Jul 20, 2012 at 05:49:02PM -0700, David Miller wrote: > From: "Michael S. Tsirkin" > Date: Fri, 20 Jul 2012 22:23:03 +0300 > > > Same as with macvtap, I get single-percentage wins in CPU utilization > > on guest to external from this patchset, and a performance regression on > > guest to

Re: [PATCHv3 0/6] tun zerocopy support

2012-07-20 Thread David Miller
From: "Michael S. Tsirkin" Date: Fri, 20 Jul 2012 22:23:03 +0300 > Same as with macvtap, I get single-percentage wins in CPU utilization > on guest to external from this patchset, and a performance regression on > guest to host, so more work is needed until this feature can move out of > experime

[PATCHv3 0/6] tun zerocopy support

2012-07-20 Thread Michael S. Tsirkin
This adds support for experimental zero copy transmit to tun. This includes some patches from Ian's patchset to support zerocopy with tun, so it should help that work progress: we are still trying to figure out how to make everything work properly with tcp but tun seems easier, and it's helpful by