net: Fixup virtnet_set_affinity() cause cpumask warning

  From: Guo Ren <guoren@linux.alibaba.com>

Don't pass nr_bits-1 as arg1 for cpumask_next_wrap, which would
cause warning now.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at include/linux/cpumask.h:110 cpumask_next_wrap+0x5c/0x80
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.0.0-11659-ge7e38f6cce55-dirty #328
Hardware name: riscv-virtio,qemu (DT)
epc : cpumask_next_wrap+0x5c/0x80
 ra : virtnet_set_affinity+0x1ba/0x1fc
epc : ffffffff808992ca ra : ffffffff805d84ca sp : ff60000002327a50
 gp : ffffffff81602390 tp : ff600000023a0000 t0 : 5f74656e74726976
 t1 : 0000000000000000 t2 : 735f74656e747269 s0 : ff60000002327a90
 s1 : 0000000000000003 a0 : 0000000000000003 a1 : ffffffff816051c0
 a2 : 0000000000000004 a3 : 0000000000000000 a4 : 0000000000000000
 a5 : 0000000000000004 a6 : 0000000000000000 a7 : 0000000000000000
 s2 : 0000000000000000 s3 : ffffffff816051c0 s4 : ffffffff8160224c
 s5 : 0000000000000004 s6 : 0000000000000004 s7 : 0000000000000000
 s8 : 0000000000000003 s9 : ffffffff810aa398 s10: ffffffff80e97d20
 s11: 0000000000000004 t3 : ffffffff819acc97 t4 : ffffffff819acc97
 t5 : ffffffff819acc98 t6 : ff60000002327878
status: 0000000200000120 badaddr: 0000000000000000 cause: 0000000000000003
[<ffffffff805d84ca>] virtnet_set_affinity+0x1ba/0x1fc
[<ffffffff805da7ac>] virtnet_probe+0x832/0xf1e
[<ffffffff804fe61c>] virtio_dev_probe+0x164/0x2de
[<ffffffff8054c4c4>] really_probe+0x82/0x224
[<ffffffff8054c6c0>] __driver_probe_device+0x5a/0xaa
[<ffffffff8054c73c>] driver_probe_device+0x2c/0xb8
[<ffffffff8054cd66>] __driver_attach+0x76/0x108
[<ffffffff8054a482>] bus_for_each_dev+0x52/0x9a
[<ffffffff8054be8c>] driver_attach+0x1a/0x28
[<ffffffff8054b996>] bus_add_driver+0x154/0x1c2
[<ffffffff8054d592>] driver_register+0x52/0x108
[<ffffffff804fe120>] register_virtio_driver+0x1c/0x2c
[<ffffffff80a29142>] virtio_net_driver_init+0x7a/0xb0
[<ffffffff80002854>] do_one_initcall+0x66/0x2e4
[<ffffffff80a01222>] kernel_init_freeable+0x28a/0x304
[<ffffffff808cb1be>] kernel_init+0x1e/0x110
[<ffffffff80003c4e>] ret_from_exception+0x0/0x10
---[ end trace 0000000000000000 ]---

Fixes: 78e5a3399421 ("cpumask: fix checking valid cpu range")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
 drivers/net/virtio_net.c | 2 ++
 1 file changed, 2 insertions(+)
  

On Thu, Oct 13, 2022 at 10:14 AM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> Don't pass nr_bits-1 as arg1 for cpumask_next_wrap, which would
> cause warning now.
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 1 at include/linux/cpumask.h:110 cpumask_next_wrap+0x5c/0x80
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.0.0-11659-ge7e38f6cce55-dirty #328
> Hardware name: riscv-virtio,qemu (DT)
> epc : cpumask_next_wrap+0x5c/0x80
>  ra : virtnet_set_affinity+0x1ba/0x1fc
> epc : ffffffff808992ca ra : ffffffff805d84ca sp : ff60000002327a50
>  gp : ffffffff81602390 tp : ff600000023a0000 t0 : 5f74656e74726976
>  t1 : 0000000000000000 t2 : 735f74656e747269 s0 : ff60000002327a90
>  s1 : 0000000000000003 a0 : 0000000000000003 a1 : ffffffff816051c0
>  a2 : 0000000000000004 a3 : 0000000000000000 a4 : 0000000000000000
>  a5 : 0000000000000004 a6 : 0000000000000000 a7 : 0000000000000000
>  s2 : 0000000000000000 s3 : ffffffff816051c0 s4 : ffffffff8160224c
>  s5 : 0000000000000004 s6 : 0000000000000004 s7 : 0000000000000000
>  s8 : 0000000000000003 s9 : ffffffff810aa398 s10: ffffffff80e97d20
>  s11: 0000000000000004 t3 : ffffffff819acc97 t4 : ffffffff819acc97
>  t5 : ffffffff819acc98 t6 : ff60000002327878
> status: 0000000200000120 badaddr: 0000000000000000 cause: 0000000000000003
> [<ffffffff805d84ca>] virtnet_set_affinity+0x1ba/0x1fc
> [<ffffffff805da7ac>] virtnet_probe+0x832/0xf1e
> [<ffffffff804fe61c>] virtio_dev_probe+0x164/0x2de
> [<ffffffff8054c4c4>] really_probe+0x82/0x224
> [<ffffffff8054c6c0>] __driver_probe_device+0x5a/0xaa
> [<ffffffff8054c73c>] driver_probe_device+0x2c/0xb8
> [<ffffffff8054cd66>] __driver_attach+0x76/0x108
> [<ffffffff8054a482>] bus_for_each_dev+0x52/0x9a
> [<ffffffff8054be8c>] driver_attach+0x1a/0x28
> [<ffffffff8054b996>] bus_add_driver+0x154/0x1c2
> [<ffffffff8054d592>] driver_register+0x52/0x108
> [<ffffffff804fe120>] register_virtio_driver+0x1c/0x2c
> [<ffffffff80a29142>] virtio_net_driver_init+0x7a/0xb0
> [<ffffffff80002854>] do_one_initcall+0x66/0x2e4
> [<ffffffff80a01222>] kernel_init_freeable+0x28a/0x304
> [<ffffffff808cb1be>] kernel_init+0x1e/0x110
> [<ffffffff80003c4e>] ret_from_exception+0x0/0x10
> ---[ end trace 0000000000000000 ]---
>
> Fixes: 78e5a3399421 ("cpumask: fix checking valid cpu range")

Please stop saying you're fixing my patch. It reveals the problem, not
creates it.

I have a deep rework for cpumask_next_wrap(). Will send v2 soon and CC you.

Thanks,
Yury

> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> ---
>  drivers/net/virtio_net.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 7106932c6f88..e4b56523b2b5 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2300,6 +2300,8 @@ static void virtnet_set_affinity(struct virtnet_info *vi)
>
>                 for (j = 0; j < group_size; j++) {
>                         cpumask_set_cpu(cpu, mask);
> +                       if (cpu == (nr_cpu_ids - 1))
> +                               break;
>                         cpu = cpumask_next_wrap(cpu, cpu_online_mask,
>                                                 nr_cpu_ids, false);
>                 }
> --
> 2.36.1
>
  

On Fri, Oct 14, 2022 at 2:13 AM Yury Norov <yury.norov@gmail.com> wrote:
>
> On Thu, Oct 13, 2022 at 10:14 AM <guoren@kernel.org> wrote:
> >
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Don't pass nr_bits-1 as arg1 for cpumask_next_wrap, which would
> > cause warning now.
> >
> > ------------[ cut here ]------------
> > WARNING: CPU: 0 PID: 1 at include/linux/cpumask.h:110 cpumask_next_wrap+0x5c/0x80
> > Modules linked in:
> > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.0.0-11659-ge7e38f6cce55-dirty #328
> > Hardware name: riscv-virtio,qemu (DT)
> > epc : cpumask_next_wrap+0x5c/0x80
> >  ra : virtnet_set_affinity+0x1ba/0x1fc
> > epc : ffffffff808992ca ra : ffffffff805d84ca sp : ff60000002327a50
> >  gp : ffffffff81602390 tp : ff600000023a0000 t0 : 5f74656e74726976
> >  t1 : 0000000000000000 t2 : 735f74656e747269 s0 : ff60000002327a90
> >  s1 : 0000000000000003 a0 : 0000000000000003 a1 : ffffffff816051c0
> >  a2 : 0000000000000004 a3 : 0000000000000000 a4 : 0000000000000000
> >  a5 : 0000000000000004 a6 : 0000000000000000 a7 : 0000000000000000
> >  s2 : 0000000000000000 s3 : ffffffff816051c0 s4 : ffffffff8160224c
> >  s5 : 0000000000000004 s6 : 0000000000000004 s7 : 0000000000000000
> >  s8 : 0000000000000003 s9 : ffffffff810aa398 s10: ffffffff80e97d20
> >  s11: 0000000000000004 t3 : ffffffff819acc97 t4 : ffffffff819acc97
> >  t5 : ffffffff819acc98 t6 : ff60000002327878
> > status: 0000000200000120 badaddr: 0000000000000000 cause: 0000000000000003
> > [<ffffffff805d84ca>] virtnet_set_affinity+0x1ba/0x1fc
> > [<ffffffff805da7ac>] virtnet_probe+0x832/0xf1e
> > [<ffffffff804fe61c>] virtio_dev_probe+0x164/0x2de
> > [<ffffffff8054c4c4>] really_probe+0x82/0x224
> > [<ffffffff8054c6c0>] __driver_probe_device+0x5a/0xaa
> > [<ffffffff8054c73c>] driver_probe_device+0x2c/0xb8
> > [<ffffffff8054cd66>] __driver_attach+0x76/0x108
> > [<ffffffff8054a482>] bus_for_each_dev+0x52/0x9a
> > [<ffffffff8054be8c>] driver_attach+0x1a/0x28
> > [<ffffffff8054b996>] bus_add_driver+0x154/0x1c2
> > [<ffffffff8054d592>] driver_register+0x52/0x108
> > [<ffffffff804fe120>] register_virtio_driver+0x1c/0x2c
> > [<ffffffff80a29142>] virtio_net_driver_init+0x7a/0xb0
> > [<ffffffff80002854>] do_one_initcall+0x66/0x2e4
> > [<ffffffff80a01222>] kernel_init_freeable+0x28a/0x304
> > [<ffffffff808cb1be>] kernel_init+0x1e/0x110
> > [<ffffffff80003c4e>] ret_from_exception+0x0/0x10
> > ---[ end trace 0000000000000000 ]---
> >
> > Fixes: 78e5a3399421 ("cpumask: fix checking valid cpu range")
>
> Please stop saying you're fixing my patch. It reveals the problem, not
> creates it.
Okay, I would change it to:
Fixes: 2ca653d607ce ("virtio_net: Stripe queue affinities across cores.")

But I still need to mention your patch, because it causes the problem
from the git bisect view. But I agree that "yours reveals the problem,
not creates it."

>
> I have a deep rework for cpumask_next_wrap(). Will send v2 soon and CC you.
>
> Thanks,
> Yury
>
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > ---
> >  drivers/net/virtio_net.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 7106932c6f88..e4b56523b2b5 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -2300,6 +2300,8 @@ static void virtnet_set_affinity(struct virtnet_info *vi)
> >
> >                 for (j = 0; j < group_size; j++) {
> >                         cpumask_set_cpu(cpu, mask);
> > +                       if (cpu == (nr_cpu_ids - 1))
> > +                               break;
> >                         cpu = cpumask_next_wrap(cpu, cpu_online_mask,
> >                                                 nr_cpu_ids, false);
> >                 }
> > --
> > 2.36.1
> >