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| author | David Vrabel <david.vrabel@citrix.com> | 2015-01-20 17:49:52 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-01-24 05:01:58 +0300 |
| commit | 1650d5455bd2dc6b5ee134bd6fc1a3236c266b5b (patch) | |
| tree | ade96080aac11eaf88a50f000a60c46ef633fb39 /drivers/net/xen-netback/common.h | |
| parent | f4ac8292b09350868418983fc1b85a6c6e48a177 (diff) | |
| download | linux-1650d5455bd2dc6b5ee134bd6fc1a3236c266b5b.tar.xz | |
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>
Diffstat (limited to 'drivers/net/xen-netback/common.h')
| -rw-r--r-- | drivers/net/xen-netback/common.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 5f1fda44882b..589fa256256b 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -251,7 +251,6 @@ struct xenvif { struct xenvif_rx_cb { unsigned long expires; int meta_slots_used; - bool full_coalesce; }; #define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb) |