Re: [dpdk-dev] [PATCH v2] Adding RTE_KNI_PREEMPT_DEFAULT configuration option

["Zhang, Helin" <helin.zhang@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Marc Sune
> Sent: Friday, February 13, 2015 10:25 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH v2] Adding RTE_KNI_PREEMPT_DEFAULT
> configuration option
> 
> This patch introduces CONFIG_RTE_KNI_PREEMPT_DEFAULT flag. When set to
> 'no', KNI kernel thread(s) do not call schedule_timeout_interruptible(), which
> improves overall KNI performance at the expense of CPU cycles (polling).
> 
> Default values is 'yes', maintaining the same behaviour as of now.
> 
> v2: CONFIG_RTE_KNI_PREEMPT -> CONFIG_RTE_KNI_PREEMPT_DEFAULT
> 
> Signed-off-by: Marc Sune <marc.sune@bisdn.de>
Acked-by: Helin Zhang <helin.zhang@intel.com>

> ---
>  config/common_linuxapp                 | 1 +
>  lib/librte_eal/linuxapp/kni/kni_misc.c | 4 ++++
>  2 files changed, 5 insertions(+)
> 
> diff --git a/config/common_linuxapp b/config/common_linuxapp index
> d428f84..72ba6ab 100644
> --- a/config/common_linuxapp
> +++ b/config/common_linuxapp
> @@ -359,6 +359,7 @@ CONFIG_RTE_LIBRTE_PIPELINE=y  # Compile
> librte_kni  #  CONFIG_RTE_LIBRTE_KNI=y
> +CONFIG_RTE_KNI_PREEMPT_DEFAULT=y
>  CONFIG_RTE_KNI_KO_DEBUG=n
>  CONFIG_RTE_KNI_VHOST=n
>  CONFIG_RTE_KNI_VHOST_MAX_CACHE_SIZE=1024
> diff --git a/lib/librte_eal/linuxapp/kni/kni_misc.c
> b/lib/librte_eal/linuxapp/kni/kni_misc.c
> index 868b325..1935d32 100644
> --- a/lib/librte_eal/linuxapp/kni/kni_misc.c
> +++ b/lib/librte_eal/linuxapp/kni/kni_misc.c
> @@ -229,9 +229,11 @@ kni_thread_single(void *unused)
>  			}
>  		}
>  		up_read(&kni_list_lock);
> +#ifdef RTE_KNI_PREEMPT_DEFAULT
>  		/* reschedule out for a while */
>  		schedule_timeout_interruptible(usecs_to_jiffies( \
>  				KNI_KTHREAD_RESCHEDULE_INTERVAL));
> +#endif
>  	}
> 
>  	return 0;
> @@ -252,8 +254,10 @@ kni_thread_multiple(void *param)  #endif
>  			kni_net_poll_resp(dev);
>  		}
> +#ifdef RTE_KNI_PREEMPT_DEFAULT
>  		schedule_timeout_interruptible(usecs_to_jiffies( \
>  				KNI_KTHREAD_RESCHEDULE_INTERVAL));
> +#endif
>  	}
> 
>  	return 0;
> --
> 2.1.4