Module Name: src
Committed By: jdolecek
Date: Sun Apr 26 13:09:53 UTC 2020
Modified Files:
src/sys/arch/xen/xen: xennetback_xenbus.c
Log Message:
bump send queue to 2*NET_TX_RING_SIZE to make it less likely packets
are dropped on load
m_defrag() short packets before calling bus_dmamap_load_mbuf() -
if it's fragmented load_mbuf would fail anyway, and even with
eventual feature-sg support it's way faster to pass the short packet
in single fragment
To generate a diff of this commit:
cvs rdiff -u -r1.97 -r1.98 src/sys/arch/xen/xen/xennetback_xenbus.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/xennetback_xenbus.c
diff -u src/sys/arch/xen/xen/xennetback_xenbus.c:1.97 src/sys/arch/xen/xen/xennetback_xenbus.c:1.98
--- src/sys/arch/xen/xen/xennetback_xenbus.c:1.97 Sat Apr 25 11:33:28 2020
+++ src/sys/arch/xen/xen/xennetback_xenbus.c Sun Apr 26 13:09:52 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: xennetback_xenbus.c,v 1.97 2020/04/25 11:33:28 jdolecek Exp $ */
+/* $NetBSD: xennetback_xenbus.c,v 1.98 2020/04/26 13:09:52 jdolecek Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -25,7 +25,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xennetback_xenbus.c,v 1.97 2020/04/25 11:33:28 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xennetback_xenbus.c,v 1.98 2020/04/26 13:09:52 jdolecek Exp $");
#include "opt_xen.h"
@@ -269,6 +269,7 @@ xennetback_xenbus_create(struct xenbus_d
ifp->if_init = xennetback_ifinit;
ifp->if_stop = xennetback_ifstop;
ifp->if_timer = 0;
+ IFQ_SET_MAXLEN(&ifp->if_snd, uimax(2 * NET_TX_RING_SIZE, IFQ_MAXLEN));
IFQ_SET_READY(&ifp->if_snd);
if_attach(ifp);
if_deferred_start_init(ifp, NULL);
@@ -912,6 +913,15 @@ xennetback_ifsoftstart_copy(struct xnetb
xst = &xneti->xni_xstate[i];
+ /*
+ * For short packets it's always way faster passing
+ * single defragmented packet, even with feature-sg.
+ * Try to defragment first if the result is likely
+ * to fit into a single mbuf.
+ */
+ if (m->m_pkthdr.len < MCLBYTES && m->m_next)
+ (void)m_defrag(m, M_DONTWAIT);
+
if (bus_dmamap_load_mbuf(
xneti->xni_xbusd->xbusd_dmat,
xst->xs_dmamap, m, BUS_DMA_NOWAIT) != 0) {
