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[PATCH v3 5/9] vhost: Add kthread support in function vhost_worker_queue()

Cindy Lu posted 9 patches 1 year, 3 months ago
There is a newer version of this series
[PATCH v3 5/9] vhost: Add kthread support in function vhost_worker_queue()
Posted by Cindy Lu 1 year, 3 months ago 
The function vhost_worker_queue() uses vhost_task_fn and
selects the different mode based on the value of inherit_owner.

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 drivers/vhost/vhost.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 603b146fccc1..8b7ddfb33c61 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -238,13 +238,18 @@ EXPORT_SYMBOL_GPL(vhost_poll_stop);
 static void vhost_worker_queue(struct vhost_worker *worker,
 			       struct vhost_work *work)
 {
+	if (!worker && !worker->fn)
+		return;
+
 	if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
 		/* We can only add the work to the list after we're
 		 * sure it was not in the list.
 		 * test_and_set_bit() implies a memory barrier.
 		 */
 		llist_add(&work->node, &worker->work_list);
-		vhost_task_wake(worker->vtsk);
+		worker->fn->wakeup(worker->dev->inherit_owner ?
+					   (void *)worker->vtsk :
+					   (void *)worker->task);
 	}
 }
 
-- 
2.45.0
Re: [PATCH v3 5/9] vhost: Add kthread support in function vhost_worker_queue()
Posted by Dan Carpenter 1 year, 3 months ago 
Hi Cindy,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Cindy-Lu/vhost-Add-a-new-parameter-to-allow-user-select-kthread/20241105-153254
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link:    https://lore.kernel.org/r/20241105072642.898710-6-lulu%40redhat.com
patch subject: [PATCH v3 5/9] vhost: Add kthread support in function vhost_worker_queue()
config: x86_64-randconfig-161-20241106 (https://download.01.org/0day-ci/archive/20241107/202411071251.tQLG8K6C-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202411071251.tQLG8K6C-lkp@intel.com/

New smatch warnings:
drivers/vhost/vhost.c:241 vhost_worker_queue() error: we previously assumed 'worker' could be null (see line 241)

Old smatch warnings:
drivers/vhost/vhost.c:311 vhost_dev_flush() warn: iterator 'i' not incremented
drivers/vhost/vhost.c:678 vhost_attach_cgroups() error: uninitialized symbol 'ret'.
drivers/vhost/vhost.c:673 vhost_attach_cgroups() warn: iterator 'i' not incremented

vim +/worker +241 drivers/vhost/vhost.c

228a27cf78afc63 Mike Christie      2023-06-26  238  static void vhost_worker_queue(struct vhost_worker *worker,
0921dddcb589803 Mike Christie      2023-06-26  239  			       struct vhost_work *work)
3a4d5c94e959359 Michael S. Tsirkin 2010-01-14  240  {
001268765c12bbf Cindy Lu           2024-11-05 @241  	if (!worker && !worker->fn)

|| was intended instead of &&.

001268765c12bbf Cindy Lu           2024-11-05  242  		return;
001268765c12bbf Cindy Lu           2024-11-05  243  
04b96e5528ca971 Jason Wang         2016-04-25  244  	if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
04b96e5528ca971 Jason Wang         2016-04-25  245  		/* We can only add the work to the list after we're
04b96e5528ca971 Jason Wang         2016-04-25  246  		 * sure it was not in the list.
635abf01918157e Peng Tao           2016-12-07  247  		 * test_and_set_bit() implies a memory barrier.
04b96e5528ca971 Jason Wang         2016-04-25  248  		 */
0921dddcb589803 Mike Christie      2023-06-26  249  		llist_add(&work->node, &worker->work_list);
001268765c12bbf Cindy Lu           2024-11-05  250  		worker->fn->wakeup(worker->dev->inherit_owner ?
001268765c12bbf Cindy Lu           2024-11-05  251  					   (void *)worker->vtsk :
001268765c12bbf Cindy Lu           2024-11-05  252  					   (void *)worker->task);
3a4d5c94e959359 Michael S. Tsirkin 2010-01-14  253  	}
ac9fde2474d04bd Qin Chuanyu        2013-06-07  254  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH v3 5/9] vhost: Add kthread support in function vhost_worker_queue()
Posted by Dan Carpenter 1 year, 3 months ago 
On Thu, Nov 07, 2024 at 01:38:56PM +0300, Dan Carpenter wrote:
> Hi Cindy,
> 
> kernel test robot noticed the following build warnings:
> 
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Cindy-Lu/vhost-Add-a-new-parameter-to-allow-user-select-kthread/20241105-153254
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
> patch link:    https://lore.kernel.org/r/20241105072642.898710-6-lulu%40redhat.com
> patch subject: [PATCH v3 5/9] vhost: Add kthread support in function vhost_worker_queue()
> config: x86_64-randconfig-161-20241106 (https://download.01.org/0day-ci/archive/20241107/202411071251.tQLG8K6C-lkp@intel.com/config)
> compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> | Closes: https://lore.kernel.org/r/202411071251.tQLG8K6C-lkp@intel.com/
> 
> New smatch warnings:
> drivers/vhost/vhost.c:241 vhost_worker_queue() error: we previously assumed 'worker' could be null (see line 241)
> 

I only meant to send this warning.

> Old smatch warnings:
> drivers/vhost/vhost.c:311 vhost_dev_flush() warn: iterator 'i' not incremented
> drivers/vhost/vhost.c:678 vhost_attach_cgroups() error: uninitialized symbol 'ret'.
> drivers/vhost/vhost.c:673 vhost_attach_cgroups() warn: iterator 'i' not incremented
> 

Not these.  I need to fix these for systems without the cross function
DB...  #embarassing.

regards,
dan carpenter
Re: [PATCH v3 5/9] vhost: Add kthread support in function vhost_worker_queue()
Posted by Jason Wang 1 year, 3 months ago 
On Tue, Nov 5, 2024 at 3:27 PM Cindy Lu <lulu@redhat.com> wrote:
>
> The function vhost_worker_queue() uses vhost_task_fn and
> selects the different mode based on the value of inherit_owner.
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>  drivers/vhost/vhost.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 603b146fccc1..8b7ddfb33c61 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -238,13 +238,18 @@ EXPORT_SYMBOL_GPL(vhost_poll_stop);
>  static void vhost_worker_queue(struct vhost_worker *worker,
>                                struct vhost_work *work)
>  {
> +       if (!worker && !worker->fn)
> +               return;
> +
>         if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) {
>                 /* We can only add the work to the list after we're
>                  * sure it was not in the list.
>                  * test_and_set_bit() implies a memory barrier.
>                  */
>                 llist_add(&work->node, &worker->work_list);
> -               vhost_task_wake(worker->vtsk);
> +               worker->fn->wakeup(worker->dev->inherit_owner ?
> +                                          (void *)worker->vtsk :
> +                                          (void *)worker->task);

Logically, it looks better to introduce the ops before introducing
back the kthread behaviour?

Thanks

>         }
>  }
>
> --
> 2.45.0
>

Patchew 2.1-devel-b67e4c2

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