| Message ID | 1481277572-18283-1-git-send-email-yuriy.kolerov@synopsys.com |
|---|---|
| State | New |
| Headers | show |
Hi Yuriy, On 12/09/2016 01:59 AM, Yuriy Kolerov wrote: > By default the kernel sets a value for default affinity which may > not correspond to the real bitmap of potentially online CPUs. E.g. > for ARC HS processors with 2 cores the default value of affinity in > the kernel may be 0xF and it is wrong in this case. This happens > because init_irq_default_affinity() sets all bits in > irq_default_affinity variable by default. > > It is better to set the default value of affinity to the boot core > to guarantee that value of irq_default_affinity contains at least > one valid online CPU during the early stage of booting. It is > necessary for proper configuration of affinity for common interrupt. > > Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com> > --- > arch/arc/kernel/irq.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c > index 538b36a..e53bfd5 100644 > --- a/arch/arc/kernel/irq.c > +++ b/arch/arc/kernel/irq.c > @@ -20,6 +20,12 @@ > */ > void __init init_IRQ(void) > { > +#ifdef CONFIG_SMP > + /* Set the default affinity to the boot cpu. */ > + cpumask_clear(irq_default_affinity); > + cpumask_set_cpu(smp_processor_id(), irq_default_affinity); > +#endif > + > /* > * process the entire interrupt tree in one go > * Any external intc will be setup provided DT chains them For a multi patch series, always include a cover letter. This gives an idea of over intent of the series. Also there is no record of what changed between v1 and v2. Reviewers typically have a short memory span :-) Also try to include all the reviewers: in this case Marc Z gave very good feedback and direction for patches. This is just a general lkml submission best practice ! Now on to the patch itself, I don't like arch code fudging a core genirq global variable. If at all this needs to be moved into core code - assuming this is the right thing to do ! Marc , tglx ? -Vineet
diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c index 538b36a..e53bfd5 100644 --- a/arch/arc/kernel/irq.c +++ b/arch/arc/kernel/irq.c @@ -20,6 +20,12 @@ */ void __init init_IRQ(void) { +#ifdef CONFIG_SMP + /* Set the default affinity to the boot cpu. */ + cpumask_clear(irq_default_affinity); + cpumask_set_cpu(smp_processor_id(), irq_default_affinity); +#endif + /* * process the entire interrupt tree in one go * Any external intc will be setup provided DT chains them
By default the kernel sets a value for default affinity which may not correspond to the real bitmap of potentially online CPUs. E.g. for ARC HS processors with 2 cores the default value of affinity in the kernel may be 0xF and it is wrong in this case. This happens because init_irq_default_affinity() sets all bits in irq_default_affinity variable by default. It is better to set the default value of affinity to the boot core to guarantee that value of irq_default_affinity contains at least one valid online CPU during the early stage of booting. It is necessary for proper configuration of affinity for common interrupt. Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com> --- arch/arc/kernel/irq.c | 6 ++++++ 1 file changed, 6 insertions(+)