On 11/02/15 02:54, Zhang, Helin wrote: > >> -----Original Message----- >> From: Richardson, Bruce >> Sent: Tuesday, February 10, 2015 9:24 PM >> To: Marc Sune >> Cc: dev at dpdk.org; Zhang, Helin >> Subject: Re: [dpdk-dev] [PATCH] Adding RTE_KNI_PREEMPT configuration >> option >> >> On Tue, Feb 10, 2015 at 12:59:29PM +0100, Marc Sune wrote: >>> This patch of Nov 2014 hasn't been yet ACKed/NACKed. Could someone >>> please give some quick feedback? >>> >>> Thanks >>> marc >>> >>> On 07/11/14 12:00, Marc Sune wrote: >>>> This patch introduces CONFIG_RTE_KNI_PREEMPT 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. >>>> >>>> Signed-off-by: Marc Sune <marc.sune at bisdn.de> >> Although a better option would be to have a runtime setting, this is still an >> improvement over what we have. >> >> Acked-by: Bruce Richardson <bruce.richardson at 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 >>>> 57b61c9..24b529d 100644 >>>> --- a/config/common_linuxapp >>>> +++ b/config/common_linuxapp >>>> @@ -380,6 +380,7 @@ CONFIG_RTE_LIBRTE_PIPELINE=y >>>> # Compile librte_kni >>>> # >>>> CONFIG_RTE_LIBRTE_KNI=y >>>> +CONFIG_RTE_KNI_PREEMPT=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 ba77776..e7e6c27 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 >>>> /* 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 >>>> schedule_timeout_interruptible(usecs_to_jiffies( \ >>>> KNI_KTHREAD_RESCHEDULE_INTERVAL)); >>>> +#endif >>>> } >>>> return 0; > As Bruce indicated, it would be better to do that at runtime, we can > add a config in struct rte_kni_conf, which will be copied to > struct rte_kni_device_info, then kernel space will know the configuration. > This way, we can enable/disable PREEMPT during KNI instance allocation time.
As I said before, I see the point on having it at runtime and I agree. However, rte_kni_device_info is a struct that is per interface, not for the entire KNI subsystem, so it is kind of abusing to add a flag there when only will be used once, at bootstrap. To do it "properly" we should create a new ioctl() call IMHO. > Anyway, it can be done now or later. So, do we integrate the current patch, as acked by Bruce before? Marc > > Regards, > Helin >
