Messages in this thread Patch in this message | | | Subject | Re: tun.c patch to fix "smp_processor_id() in preemptible code" | From | Lee Revell <> | Date | Tue, 19 Oct 2004 17:51:17 -0400 |
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On Tue, 2004-10-19 at 17:35, Herbert Xu wrote: > Lee Revell <rlrevell@joe-job.com> wrote: > > > > I looked at Robert Love's book and I am still unclear on the use of > > do_softirq above. To reiterate the question: why does netif_rx_ni have > > to manually flush any pending softirqs on the current proccessor after > > doing the rx? Is this just a performance hack? > > Yes it allows the packet to be processed immediately.
Ok, here is the correct patch. If this is really just a matter of performance, and not required for correctness, disabling preemption is broken, right?
Lee
--- include/linux/netdevice.h~ 2004-10-15 20:19:33.000000000 -0400 +++ include/linux/netdevice.h 2004-10-19 17:47:03.000000000 -0400 @@ -697,8 +697,6 @@ static inline int netif_rx_ni(struct sk_buff *skb) { int err = netif_rx(skb); - if (softirq_pending(smp_processor_id())) - do_softirq(); return err; }
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