* [PATCH] vhost: wake up worker outside spin_lock
@ 2013-06-07 13:50 Qin Chuanyu
2013-06-07 14:05 ` Asias He
2013-06-09 9:47 ` Michael S. Tsirkin
0 siblings, 2 replies; 4+ messages in thread
From: Qin Chuanyu @ 2013-06-07 13:50 UTC (permalink / raw)
To: mst, jasowang; +Cc: kvm, netdev
the wake_up_process func is included by spin_lock/unlock in
vhost_work_queue,
but it could be done outside the spin_lock.
I have test it with kernel 3.0.27 and guest suse11-sp2 using iperf,
the num as below.
original modified
thread_num tp(Gbps) vhost(%) | tp(Gbps) vhost(%)
1 9.59 28.82 | 9.59 27.49
8 9.61 32.92 | 9.62 26.77
64 9.58 46.48 | 9.55 38.99
256 9.6 63.7 | 9.6 52.59
Signed-off-by: Chuanyu Qin <qinchuanyu@huawei.com>
---
drivers/vhost/vhost.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 94dbd25..dcc7a17 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -146,9 +146,11 @@ static inline void vhost_work_queue(struct
vhost_dev *dev,
if (list_empty(&work->node)) {
list_add_tail(&work->node, &dev->work_list);
work->queue_seq++;
+ spin_unlock_irqrestore(&dev->work_lock, flags);
wake_up_process(dev->worker);
+ } else {
+ spin_unlock_irqrestore(&dev->work_lock, flags);
}
- spin_unlock_irqrestore(&dev->work_lock, flags);
}
void vhost_poll_queue(struct vhost_poll *poll)
--
1.7.3.1.msysgit.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] vhost: wake up worker outside spin_lock
2013-06-07 13:50 [PATCH] vhost: wake up worker outside spin_lock Qin Chuanyu
@ 2013-06-07 14:05 ` Asias He
2013-06-09 9:47 ` Michael S. Tsirkin
1 sibling, 0 replies; 4+ messages in thread
From: Asias He @ 2013-06-07 14:05 UTC (permalink / raw)
To: Qin Chuanyu; +Cc: Michael S. Tsirkin, Jason Wang, KVM, netdev
On Fri, Jun 7, 2013 at 9:50 PM, Qin Chuanyu <qinchuanyu@huawei.com> wrote:
> the wake_up_process func is included by spin_lock/unlock in
> vhost_work_queue,
> but it could be done outside the spin_lock.
> I have test it with kernel 3.0.27 and guest suse11-sp2 using iperf,
> the num as below.
> original modified
>
> thread_num tp(Gbps) vhost(%) | tp(Gbps) vhost(%)
> 1 9.59 28.82 | 9.59 27.49
> 8 9.61 32.92 | 9.62 26.77
> 64 9.58 46.48 | 9.55 38.99
> 256 9.6 63.7 | 9.6 52.59
>
> Signed-off-by: Chuanyu Qin <qinchuanyu@huawei.com>
> ---
> drivers/vhost/vhost.c | 4 +++-
>
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 94dbd25..dcc7a17 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -146,9 +146,11 @@ static inline void vhost_work_queue(struct vhost_dev
> *dev,
>
> if (list_empty(&work->node)) {
> list_add_tail(&work->node, &dev->work_list);
> work->queue_seq++;
> + spin_unlock_irqrestore(&dev->work_lock, flags);
> wake_up_process(dev->worker);
> + } else {
> + spin_unlock_irqrestore(&dev->work_lock, flags);
> }
> - spin_unlock_irqrestore(&dev->work_lock, flags);
>
> }
Hmm, this looks more clearer to me.
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -156,14 +156,17 @@ EXPORT_SYMBOL_GPL(vhost_poll_flush);
void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
{
unsigned long flags;
+ bool wakeup = false;
spin_lock_irqsave(&dev->work_lock, flags);
if (list_empty(&work->node)) {
list_add_tail(&work->node, &dev->work_list);
work->queue_seq++;
- wake_up_process(dev->worker);
+ wakeup = true;
}
spin_unlock_irqrestore(&dev->work_lock, flags);
+ if (wakeup)
+ wake_up_process(dev->worker);
}
>
> void vhost_poll_queue(struct vhost_poll *poll)
> --
> 1.7.3.1.msysgit.0
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Asias
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] vhost: wake up worker outside spin_lock
2013-06-07 13:50 [PATCH] vhost: wake up worker outside spin_lock Qin Chuanyu
2013-06-07 14:05 ` Asias He
@ 2013-06-09 9:47 ` Michael S. Tsirkin
1 sibling, 0 replies; 4+ messages in thread
From: Michael S. Tsirkin @ 2013-06-09 9:47 UTC (permalink / raw)
To: Qin Chuanyu; +Cc: jasowang, kvm, netdev
On Fri, Jun 07, 2013 at 09:50:16PM +0800, Qin Chuanyu wrote:
> the wake_up_process func is included by spin_lock/unlock in
> vhost_work_queue,
> but it could be done outside the spin_lock.
> I have test it with kernel 3.0.27 and guest suse11-sp2 using iperf,
> the num as below.
> original modified
> thread_num tp(Gbps) vhost(%) | tp(Gbps) vhost(%)
> 1 9.59 28.82 | 9.59 27.49
> 8 9.61 32.92 | 9.62 26.77
> 64 9.58 46.48 | 9.55 38.99
> 256 9.6 63.7 | 9.6 52.59
>
> Signed-off-by: Chuanyu Qin <qinchuanyu@huawei.com>
> ---
> drivers/vhost/vhost.c | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 94dbd25..dcc7a17 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -146,9 +146,11 @@ static inline void vhost_work_queue(struct
> vhost_dev *dev,
Applied and queued for 3.11, thanks.
This patch is malformed because of the wrapped line above.
I've applied this by hand, so just FYI, please see
Documentation/email-clients.txt
for some hints on configuring mail properly.
> if (list_empty(&work->node)) {
> list_add_tail(&work->node, &dev->work_list);
> work->queue_seq++;
> + spin_unlock_irqrestore(&dev->work_lock, flags);
> wake_up_process(dev->worker);
> + } else {
> + spin_unlock_irqrestore(&dev->work_lock, flags);
> }
> - spin_unlock_irqrestore(&dev->work_lock, flags);
> }
>
> void vhost_poll_queue(struct vhost_poll *poll)
> --
> 1.7.3.1.msysgit.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] vhost: wake up worker outside spin_lock
@ 2013-06-07 10:59 Qinchuanyu
0 siblings, 0 replies; 4+ messages in thread
From: Qinchuanyu @ 2013-06-07 10:59 UTC (permalink / raw)
To: mst, jasowang
Cc: (kvm@vger.kernel.org), (netdev@vger.kernel.org), Heguansen
the wake_up_process func is included by spin_lock/unlock in vhost_work_queue,
but it could be done outside the spin_lock.
I have test it with kernel 3.0.27 and guest suse11-sp2 using iperf, the num as below.
orignal modified
thread_num tp(Gbps) vhost(%) | tp(Gbps) vhost(%)
1 9.59 28.82 | 9.59 27.49
8 9.61 32.92 | 9.62 26.77
64 9.58 46.48 | 9.55 38.99
256 9.6 63.7 | 9.6 52.59
Signed-off-by: Chuanyu Qin <qinchuanyu@huawei.com>
---
drivers/vhost/vhost.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 94dbd25..8bee109 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -146,9 +146,10 @@ static inline void vhost_work_queue(struct vhost_dev *dev,
if (list_empty(&work->node)) {
list_add_tail(&work->node, &dev->work_list);
work->queue_seq++;
+ spin_unlock_irqrestore(&dev->work_lock, flags);
wake_up_process(dev->worker);
- }
- spin_unlock_irqrestore(&dev->work_lock, flags);
+ } else
+ spin_unlock_irqrestore(&dev->work_lock, flags);
}
void vhost_poll_queue(struct vhost_poll *poll)
--
1.7.3.1.msysgit.0
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-06-09 9:47 UTC | newest]
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2013-06-07 14:05 ` Asias He
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