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authorSteven Rostedt <srostedt@redhat.com>2010-05-21 19:49:57 +0400
committerSteven Rostedt <rostedt@goodmis.org>2010-05-21 19:49:57 +0400
commitff5f149b6aec8edbfa3698721667acd043009a33 (patch)
treed052553eb296dfee3f01b1cb2b717cb7ccf3127a /drivers/vhost/vhost.c
parentf0218b3e9974f06014b61be8987159f4a20e011e (diff)
parent580d607cd666dfabfc1c7b0fb08c8ac690c7c87f (diff)
downloadlinux-ff5f149b6aec8edbfa3698721667acd043009a33.tar.xz
Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/core-7
Conflicts: include/linux/ftrace_event.h include/trace/ftrace.h kernel/trace/trace_event_perf.c kernel/trace/trace_kprobe.c kernel/trace/trace_syscalls.c Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'drivers/vhost/vhost.c')
-rw-r--r--drivers/vhost/vhost.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index e69d238c5af0..49fa953aaf6e 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1035,7 +1035,12 @@ int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)
/* This actually signals the guest, using eventfd. */
void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
{
- __u16 flags = 0;
+ __u16 flags;
+ /* Flush out used index updates. This is paired
+ * with the barrier that the Guest executes when enabling
+ * interrupts. */
+ smp_mb();
+
if (get_user(flags, &vq->avail->flags)) {
vq_err(vq, "Failed to get flags");
return;