On Sun, Jan 29, 2012 at 01:42:41PM +0000, Wei Liu wrote:

On Fri, 2012-01-27 at 19:22 +0000, Konrad Rzeszutek Wilk wrote:

quoted

On Tue, Jan 17, 2012 at 01:46:56PM +0000, Wei Liu wrote:

quoted

A new netback implementation which includes three major features:

 - Global page pool support
 - NAPI + kthread 1:1 model
 - Netback internal name changes

Changes in V2:
 - Fix minor bugs in V1
 - Embed pending_tx_info into page pool
 - Per-cpu scratch space
 - Notification code path clean up

This patch series is the foundation of furture work. So it is better
to get it right first. Patch 1 and 3 have the real meat.

I've been playing with these patches and couple of things
came to my mind: 
 - would it make sense to also register to the shrinker API? This way
   if the host is running low on memory it can squeeze it out of the
   pool code. Perhaps a future TODO..
 - I like the pool code. I was thinking that perhaps (in the future)
   it could be used by blkback as well, as it runs into "not enought
   request structure" with the default setting. And making this dynamic
   would be pretty sweet.

Interesting thoughts worth adding to TODO list. But I'm focusing on
multi-page ring support and split event channel at the moment, which
should help improve performance on 10G network. Hopefully I can submit
RFC patch V3 in a few days. ;-)

quoted

 - This patch set solves the CPU banding problem I've seen with the
   older netback. The older one  I could see X netback threads eating 80%
   of CPU. With this one, the number is down to 13-14%.

So you can definitly stick 'Tested-by: Konrad.." on them. And definitly
Reviewed-by on the first two - hadn't had a chance to look at the rest.

Thanks for your extensive test and review.

Sure. I also did some testing with limiting the amount of CPUs and found
that 'xl vcpu-set 0 N' make netback not work anymore :-( 

Wei.