From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v2] kni: use netif_rx instead of netif_receive_skb in which ocurr deallock on userpace contex Date: Sat, 19 Jul 2014 02:03:53 +0200 Message-ID: <5714891.ieLfUKBjNN@xps13> References: <1405093044-3264-1-git-send-email-blue119@gmail.com> <2139993.JzhFVyBpua@xps13> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev-VfR2kkLFssw@public.gmane.org To: Yao-Po Wang Return-path: In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" 2014-07-17 15:24, Alex Markuze: > On Thu, Jul 17, 2014 at 3:02 PM, Thomas Monjalon > > 2014-07-11 23:37, Yao-Po Wang: > >> Per netif_receive_skb function description, it may only be called from > >> interrupt contex, but KNI is run on kthread that like as user-space > >> contex. It may occur deallock, if netif_receive_skb called from kthread, > >> so it should be repleaced by netif_rx or adding local_bh_disable/enable > >> around netif_receive_skb. > >> > >> Signed-off-by: Yao-Po Wang > > > >> --- a/lib/librte_eal/linuxapp/kni/kni_net.c > >> +++ b/lib/librte_eal/linuxapp/kni/kni_net.c > >> /* Call netif interface */ > >> - netif_receive_skb(skb); > >> + netif_rx(skb); > > > > Is there someone confident to approve this change? > > Yao-Po is correct. > > Please see this comment In Linux source code . > http://lxr.free-electrons.com/source/net/core/dev.c#L3715 > > Context: > All todays network drivers use(ixgbe is no exception) NAPI which is a > soft irq context of the receive flow . > This is the context in which netif_receive_skb should be called in. > KNI is not soft IRQ context so the generic netif_rx is the > right function. Thanks for confirmation. Assuming Acked-by: Alex Markuze Applied for version 1.7.1 Thanks -- Thomas