[src/trunk]: src/sys/rump/net/lib Prevent LWP migrations between CPUs during ...

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6ea8aef102d6
branches:  trunk
changeset: 344772:6ea8aef102d6
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Tue Apr 19 05:48:10 2016 +0000

description:
Prevent LWP migrations between CPUs during upper layer processing

This is a contract of psref(9) that is used by upper layer componenets,
e.g., bridge(4).

diffstat:

 sys/rump/net/lib/libshmif/if_shmem.c |  8 ++++++--
 sys/rump/net/lib/libvirtif/if_virt.c |  8 ++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diffs (67 lines):

diff -r 402a2c88ac11 -r 6ea8aef102d6 sys/rump/net/lib/libshmif/if_shmem.c
--- a/sys/rump/net/lib/libshmif/if_shmem.c      Tue Apr 19 04:13:56 2016 +0000
+++ b/sys/rump/net/lib/libshmif/if_shmem.c      Tue Apr 19 05:48:10 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_shmem.c,v 1.65 2016/02/09 08:32:12 ozaki-r Exp $    */
+/*     $NetBSD: if_shmem.c,v 1.66 2016/04/19 05:48:10 ozaki-r Exp $    */
 
 /*
  * Copyright (c) 2009, 2010 Antti Kantee.  All Rights Reserved.
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.65 2016/02/09 08:32:12 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.66 2016/04/19 05:48:10 ozaki-r Exp $");
 
 #include <sys/param.h>
 #include <sys/atomic.h>
@@ -764,10 +764,14 @@
                }
 
                if (passup) {
+                       int bound = curlwp->l_pflag & LP_BOUND;
                        ifp->if_ipackets++;
                        KERNEL_LOCK(1, NULL);
+                       /* Prevent LWP migrations between CPUs for psref(9) */
+                       curlwp->l_pflag |= LP_BOUND;
                        bpf_mtap(ifp, m);
                        if_input(ifp, m);
+                       curlwp->l_pflag ^= bound ^ LP_BOUND;
                        KERNEL_UNLOCK_ONE(NULL);
                        m = NULL;
                }
diff -r 402a2c88ac11 -r 6ea8aef102d6 sys/rump/net/lib/libvirtif/if_virt.c
--- a/sys/rump/net/lib/libvirtif/if_virt.c      Tue Apr 19 04:13:56 2016 +0000
+++ b/sys/rump/net/lib/libvirtif/if_virt.c      Tue Apr 19 05:48:10 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_virt.c,v 1.50 2016/02/09 08:32:12 ozaki-r Exp $     */
+/*     $NetBSD: if_virt.c,v 1.51 2016/04/19 05:48:10 ozaki-r Exp $     */
 
 /*
  * Copyright (c) 2008, 2013 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_virt.c,v 1.50 2016/02/09 08:32:12 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_virt.c,v 1.51 2016/04/19 05:48:10 ozaki-r Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -374,11 +374,15 @@
        }
 
        if (passup) {
+               int bound = curlwp->l_pflag & LP_BOUND;
                ifp->if_ipackets++;
                m->m_pkthdr.rcvif = ifp;
                KERNEL_LOCK(1, NULL);
+               /* Prevent LWP migrations between CPUs for psref(9) */
+               curlwp->l_pflag |= LP_BOUND;
                bpf_mtap(ifp, m);
                if_input(ifp, m);
+               curlwp->l_pflag ^= bound ^ LP_BOUND;
                KERNEL_UNLOCK_LAST(NULL);
        } else {
                m_freem(m);