2024-06-06 15:46:09

by Waiman Long

Subject: Re: [PATCH v3 1/2] cgroup/cpuset: export cpuset_cpus_allowed()

On 6/6/24 11:10, Fred Griffoul wrote:
> A subsequent patch calls cpuset_cpus_allowed() in the vfio driver pci
> code. Export the symbol to be able to build the vfio driver as a kernel
> module.
>
> Signed-off-by: Fred Griffoul <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> ---
> kernel/cgroup/cpuset.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index 4237c8748715..9fd56222aa4b 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -4764,6 +4764,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
> rcu_read_unlock();
> spin_unlock_irqrestore(&callback_lock, flags);
> }
> +EXPORT_SYMBOL_GPL(cpuset_cpus_allowed);
>
> /**
> * cpuset_cpus_allowed_fallback - final fallback before complete catastrophe.

LGTM

Acked-by: Waiman Long <[email protected]>

2024-06-07 16:32:13

by Tejun Heo

Subject: Re: [PATCH v3 1/2] cgroup/cpuset: export cpuset_cpus_allowed()

On Thu, Jun 06, 2024 at 11:45:37AM -0400, Waiman Long wrote:
>
> On 6/6/24 11:10, Fred Griffoul wrote:
> > A subsequent patch calls cpuset_cpus_allowed() in the vfio driver pci
> > code. Export the symbol to be able to build the vfio driver as a kernel
> > module.
> >
> > Signed-off-by: Fred Griffoul <[email protected]>
> > Reported-by: kernel test robot <[email protected]>
> > Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > ---
> > kernel/cgroup/cpuset.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> > index 4237c8748715..9fd56222aa4b 100644
> > --- a/kernel/cgroup/cpuset.c
> > +++ b/kernel/cgroup/cpuset.c
> > @@ -4764,6 +4764,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
> > rcu_read_unlock();
> > spin_unlock_irqrestore(&callback_lock, flags);
> > }
> > +EXPORT_SYMBOL_GPL(cpuset_cpus_allowed);
> > /**
> > * cpuset_cpus_allowed_fallback - final fallback before complete catastrophe.
>
> LGTM
>
> Acked-by: Waiman Long <[email protected]>

Acked-by: Tejun Heo <[email protected]>

If more convenient, please feel free to route the patch with the rest of the
series. If you want it applied to the cgroup tree, please let me know.

Thanks.

--
tejun

2024-06-07 18:18:32

by Frederic Griffoul

Subject: Re: [PATCH v3 1/2] cgroup/cpuset: export cpuset_cpus_allowed()

Thanks. Unfortunately exporting cpuset_cpus_allowed() is not enough.
When CONFIG_CPUSETS is _not_ defined, the function is inline to return
task_cpu_possible_mask(). On arm64 the latter checks the static key
arm64_mismatched_32bit_el0, and thus this symbol must be exported too.

I wonder whether it would be better to avoid inlining cpuset_cpus_allowed()
in this case.

Br,

Fred

On Fri, Jun 7, 2024 at 5:29 PM Tejun Heo <[email protected]> wrote:
>
> On Thu, Jun 06, 2024 at 11:45:37AM -0400, Waiman Long wrote:
> >
> > On 6/6/24 11:10, Fred Griffoul wrote:
> > > A subsequent patch calls cpuset_cpus_allowed() in the vfio driver pci
> > > code. Export the symbol to be able to build the vfio driver as a kernel
> > > module.
> > >
> > > Signed-off-by: Fred Griffoul <[email protected]>
> > > Reported-by: kernel test robot <[email protected]>
> > > Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > > ---
> > > kernel/cgroup/cpuset.c | 1 +
> > > 1 file changed, 1 insertion(+)
> > >
> > > diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> > > index 4237c8748715..9fd56222aa4b 100644
> > > --- a/kernel/cgroup/cpuset.c
> > > +++ b/kernel/cgroup/cpuset.c
> > > @@ -4764,6 +4764,7 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
> > > rcu_read_unlock();
> > > spin_unlock_irqrestore(&callback_lock, flags);
> > > }
> > > +EXPORT_SYMBOL_GPL(cpuset_cpus_allowed);
> > > /**
> > > * cpuset_cpus_allowed_fallback - final fallback before complete catastrophe.
> >
> > LGTM
> >
> > Acked-by: Waiman Long <[email protected]>
>
> Acked-by: Tejun Heo <[email protected]>
>
> If more convenient, please feel free to route the patch with the rest of the
> series. If you want it applied to the cgroup tree, please let me know.
>
> Thanks.
>
> --
> tejun