linux/drivers/net/xen-netback
David Vrabel 1650d5455b xen-netback: always fully coalesce guest Rx packets
Always fully coalesce guest Rx packets into the minimum number of ring
slots.  Reducing the number of slots per packet has significant
performance benefits when receiving off-host traffic.

Results from XenServer's performance benchmarks:

                         Baseline    Full coalesce
Interhost VM receive      7.2 Gb/s   11 Gb/s
Interhost aggregate      24 Gb/s     24 Gb/s
Intrahost single stream  14 Gb/s     14 Gb/s
Intrahost aggregate      34 Gb/s     34 Gb/s

However, this can increase the number of grant ops per packet which
decreases performance of backend (dom0) to VM traffic (by ~10%)
/unless/ grant copy has been optimized for adjacent ops with the same
source or destination (see "grant-table: defer releasing pages
acquired in a grant copy"[1] expected in Xen 4.6).

[1] http://lists.xen.org/archives/html/xen-devel/2015-01/msg01118.html

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-23 18:01:58 -08:00
..
common.h xen-netback: always fully coalesce guest Rx packets 2015-01-23 18:01:58 -08:00
interface.c xen-netback: support frontends without feature-rx-notify again 2014-12-18 12:49:49 -05:00
Makefile
netback.c xen-netback: always fully coalesce guest Rx packets 2015-01-23 18:01:58 -08:00
xenbus.c xen-netback: fixing the propagation of the transmit shaper timeout 2015-01-06 14:17:37 -05:00