On Wed, 31 Oct 2012, Shan Wei wrote: > --- a/net/openvswitch/datapath.c > +++ b/net/openvswitch/datapath.c > @@ -208,7 +208,7 @@ void ovs_dp_process_received_packet(struct vport *p, > struct sk_buff *skb) > int error; > int key_len; > > - stats = per_cpu_ptr(dp->stats_percpu, smp_processor_id()); > + stats = this_cpu_ptr(dp->stats_percpu);
Well this is an improvement and may be ok if the preemption is disabled at this point. There is another possibility here to use this_cpu_read/add/inc instead of determining the pointer to the local cpu first and then performing operations on the fields. The pointer relocation with this_cpu_xxx ops is implicit in the instructions and safe against changing of processors. It would also save us the determination of a pointer to the current cpus stats structure. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
