From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: RAPOPORT@il.ibm.com, yang.zhang.wz@gmail.com,
borntraeger@de.ibm.com, Jason Wang <jasowang@redhat.com>
Subject: [PATCH V4 1/3] vhost: introduce vhost_has_work()
Date: Fri, 4 Mar 2016 06:24:51 -0500 [thread overview]
Message-ID: <1457090693-55974-2-git-send-email-jasowang@redhat.com> (raw)
In-Reply-To: <1457090693-55974-1-git-send-email-jasowang@redhat.com>
This path introduces a helper which can give a hint for whether or not
there's a work queued in the work list. This could be used for busy
polling code to exit the busy loop.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/vhost.c | 7 +++++++
drivers/vhost/vhost.h | 1 +
2 files changed, 8 insertions(+)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index ad2146a..90ac092 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -245,6 +245,13 @@ void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
}
EXPORT_SYMBOL_GPL(vhost_work_queue);
+/* A lockless hint for busy polling code to exit the loop */
+bool vhost_has_work(struct vhost_dev *dev)
+{
+ return !list_empty(&dev->work_list);
+}
+EXPORT_SYMBOL_GPL(vhost_has_work);
+
void vhost_poll_queue(struct vhost_poll *poll)
{
vhost_work_queue(poll->dev, &poll->work);
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index d3f7674..43284ad 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -37,6 +37,7 @@ struct vhost_poll {
void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
+bool vhost_has_work(struct vhost_dev *dev);
void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
unsigned long mask, struct vhost_dev *dev);
--
1.8.3.1
next prev parent reply other threads:[~2016-03-04 11:25 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-04 11:24 [PATCH V4 0/3] basic busy polling support for vhost_net Jason Wang
2016-03-04 11:24 ` Jason Wang [this message]
2016-03-04 11:24 ` [PATCH V4 2/3] vhost: introduce vhost_vq_avail_empty() Jason Wang
2016-03-04 11:24 ` [PATCH V4 3/3] vhost_net: basic polling support Jason Wang
2016-03-09 19:26 ` [PATCH V4 0/3] basic busy polling support for vhost_net Greg Kurz
2016-03-10 6:48 ` Michael Rapoport
[not found] ` <201603100648.u2A6mSTl020833@d06av07.portsmouth.uk.ibm.com>
2016-03-15 3:10 ` Jason Wang
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