[PATCH 0/3 V2] xen-netback: switch to NAPI + kthread 1:1 model

[Wei Liu <wei.liu2@citrix.com>]

* This is a xen-devel only post, since we have not reached concesus on
  what to add / remove in this new model. This series tries to be
  conservative about adding in new feature compared to V1.

This series implements NAPI + kthread 1:1 model for Xen netback.

This model
 - provides better scheduling fairness among vifs
 - is prerequisite for implementing multiqueue for Xen network driver

The first two patches are ground work for the third patch. First one
simplifies code in netback, second one can reduce memory footprint if we
switch to 1:1 model.

The third patch has the real meat:
 - make use of NAPI to mitigate interrupt 
 - kthreads are not bound to CPUs any more, so that we can take
   advantage of backend scheduler and trust it to do the right thing

Change since V1:
 - No page pool in this version. Instead page tracking facility is
   removed.

Wei Liu (3):
  xen-netback: remove page tracking facility
  xen-netback: switch to per-cpu scratch space
  xen-netback: switch to NAPI + kthread 1:1 model

 drivers/net/xen-netback/common.h    |   92 ++--
 drivers/net/xen-netback/interface.c |  122 +++--
 drivers/net/xen-netback/netback.c   |  959 +++++++++++++++--------------------
 3 files changed, 537 insertions(+), 636 deletions(-)

-- 
1.7.10.4