From 1650d5455bd2dc6b5ee134bd6fc1a3236c266b5b Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Tue, 20 Jan 2015 14:49:52 +0000 Subject: 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 Acked-by: Ian Campbell Signed-off-by: David S. Miller --- drivers/net/xen-netback/common.h | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/net/xen-netback/common.h') 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) -- cgit v1.2.3