lkml.org 
[lkml]   [2022]   [Dec]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 05/11] vduse: Introduce bound workqueue for irq injection
On Mon, Dec 19, 2022 at 1:04 PM Yongji Xie <xieyongji@bytedance.com> wrote:
>
> On Fri, Dec 16, 2022 at 12:02 PM Jason Wang <jasowang@redhat.com> wrote:
> >
> > On Mon, Dec 5, 2022 at 4:44 PM Xie Yongji <xieyongji@bytedance.com> wrote:
> > >
> > > This introduces a bound workqueue to support running
> > > irq callback in a specified cpu.
> > >
> > > Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> > > ---
> > > drivers/vdpa/vdpa_user/vduse_dev.c | 29 ++++++++++++++++++++++-------
> > > 1 file changed, 22 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> > > index 37809bfcb7ef..d126f3e32a20 100644
> > > --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> > > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> > > @@ -57,6 +57,7 @@ struct vduse_virtqueue {
> > > struct vdpa_callback cb;
> > > struct work_struct inject;
> > > struct work_struct kick;
> > > + int irq_effective_cpu;
> >
> > I wonder why it's a cpu number instead of a cpumask. The latter seems
> > more flexible, e.g when using NUMA.
> >
>
> This variable represents the CPU that runs the interrupt callback
> rather than CPU affinity.

Ok, but for some reason it only gets updated when a new affinity is set?

(Btw, I don't see how the code deals with cpu hotplug, do we need
cpuhot notifier?)

Thanks

>
> > > };
> > >
> > > struct vduse_dev;
> > > @@ -128,6 +129,7 @@ static struct class *vduse_class;
> > > static struct cdev vduse_ctrl_cdev;
> > > static struct cdev vduse_cdev;
> > > static struct workqueue_struct *vduse_irq_wq;
> > > +static struct workqueue_struct *vduse_irq_bound_wq;
> > >
> > > static u32 allowed_device_id[] = {
> > > VIRTIO_ID_BLOCK,
> > > @@ -917,7 +919,8 @@ static void vduse_vq_irq_inject(struct work_struct *work)
> > > }
> > >
> > > static int vduse_dev_queue_irq_work(struct vduse_dev *dev,
> > > - struct work_struct *irq_work)
> > > + struct work_struct *irq_work,
> > > + int irq_effective_cpu)
> > > {
> > > int ret = -EINVAL;
> > >
> > > @@ -926,7 +929,11 @@ static int vduse_dev_queue_irq_work(struct vduse_dev *dev,
> > > goto unlock;
> > >
> > > ret = 0;
> > > - queue_work(vduse_irq_wq, irq_work);
> > > + if (irq_effective_cpu == -1)
> >
> > Is it better to have a macro for this magic number?
> >
>
> It makes sense to me.
>
> Thanks,
> Yongji
>

\
 
 \ /
  Last update: 2023-03-26 23:15    [W:0.088 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site