Re: [PATCH] PCI: use local_pci_probe when best selected cpu is offline

[Hongchen Zhang]

On 2024/6/4 下午10:57, Huacai Chen wrote:
> Hi, Hongchen,
>
> On Wed, May 29, 2024 at 7:19 PM Hongchen Zhang
> <zhanghongchen@xxxxxxxxxxx> wrote:
> The title should be better like this:
> PCI: Use local_pci_probe() when best selected CPU is offline
>
> > When the best selected cpu is offline, work_on_cpu will stuck
> > forever. Therefore, in this case, we should call
> > local_pci_probe instead of work_on_cpu.
>
> It is better to reword like this:
>
> When the best selected CPU is offline, work_on_cpu() will stuck forever.
> This can be happen if a node is online while all its CPUs are offline
> (we can use "maxcpus=1" without "nr_cpus=1" to reproduce it), Therefore,
> in this case, we should call local_pci_probe() instead of work_on_cpu().
OK, Let me modify the log and send V2.
> Huacai
>
> > Cc: <stable@xxxxxxxxxxxxxxx>
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > Signed-off-by: Hongchen Zhang <zhanghongchen@xxxxxxxxxxx>
> > ---
> >   drivers/pci/pci-driver.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> > index af2996d0d17f..32a99828e6a3 100644
> > --- a/drivers/pci/pci-driver.c
> > +++ b/drivers/pci/pci-driver.c
> > @@ -386,7 +386,7 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
> >                  free_cpumask_var(wq_domain_mask);
> >          }
> >
> > -       if (cpu < nr_cpu_ids)
> > +       if ((cpu < nr_cpu_ids) && cpu_online(cpu))
> >                  error = work_on_cpu(cpu, local_pci_probe, &ddi);
> >          else
> >                  error = local_pci_probe(&ddi);
> > --
> > 2.33.0


--
Best Regards
Hongchen Zhang