Module Name: src
Committed By: riastradh
Date: Wed Aug 9 08:38:27 UTC 2023
Modified Files:
src/sys/arch/xen/xen: xennetback_xenbus.c
Log Message:
xvif(4): Omit needless membars in xennetback_evthandler.
This should improve throughput without any impact on correctness.
To generate a diff of this commit:
cvs rdiff -u -r1.119 -r1.120 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:1.119 src/sys/arch/xen/xen/xennetback_xenbus.c:1.120
--- src/sys/arch/xen/xen/xennetback_xenbus.c:1.119 Wed Aug 9 08:38:16 2023
+++ src/sys/arch/xen/xen/xennetback_xenbus.c Wed Aug 9 08:38:27 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: xennetback_xenbus.c,v 1.119 2023/08/09 08:38:16 riastradh Exp $ */
+/* $NetBSD: xennetback_xenbus.c,v 1.120 2023/08/09 08:38:27 riastradh Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -25,7 +25,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xennetback_xenbus.c,v 1.119 2023/08/09 08:38:16 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xennetback_xenbus.c,v 1.120 2023/08/09 08:38:27 riastradh Exp $");
#include <sys/types.h>
#include <sys/param.h>
@@ -813,13 +813,6 @@ xennetback_evthandler(void *arg)
XENPRINTF(("xennetback_evthandler "));
again:
while (1) {
- /*
- * XXX The xen_rmb here and comment make no sense:
- * xneti->xni_txring.req_cons is a private variable.
- */
- xen_rmb(); /* be sure to read the request before updating */
- /* XXX Unclear what this xen_wmb is for. */
- xen_wmb();
if (!RING_HAS_UNCONSUMED_REQUESTS(&xneti->xni_txring))
break;
/*
@@ -832,8 +825,6 @@ again:
RING_COPY_REQUEST(&xneti->xni_txring,
xneti->xni_txring.req_cons,
&txreq);
- /* XXX Unclear what this xen_rmb is for. */
- xen_rmb();
XENPRINTF(("%s pkt size %d\n", xneti->xni_if.if_xname,
txreq.size));
xneti->xni_txring.req_cons++;
