Re: [PATCH] [SCSI] mpt2sas : Fix unsafe using smp_processor_id() inpreemptible

[Alex Shi <alex.shi@xxxxxxxxx>]

On 04/20/2012 07:00 PM, Nandigama, Nagalakshmi wrote:

> diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
> index 272fab7..0f47f56 100644
> --- a/drivers/scsi/mpt2sas/mpt2sas_base.c
> +++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
> @@ -1792,7 +1792,10 @@ static inline void _base_writeq(__u64 b, volatile void __iomem *addr,
>  static inline u8
>  _base_get_msix_index(struct MPT2SAS_ADAPTER *ioc)
>  {
> -       return ioc->cpu_msix_table[smp_processor_id()];
> +       int cpu = get_cpu();
> +       put_cpu();
> +       return ioc->cpu_msix_table[cpu];
> +
>  }


If we don't care the correctness interrupt CPU. Do
preempt_enable/preempt_disable is just waste of time.
A patch like following is enough, :)

 _base_get_msix_index(struct MPT2SAS_ADAPTER *ioc)
 {
-       return ioc->cpu_msix_table[smp_processor_id()];
+       return ioc->cpu_msix_table[raw_smp_processor_id()];
 }


BTW, I didn't subscribe linux-scsi mailing list, so cc to me is
appreciated.
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html