> -----邮件原件----- > 发件人: Michael S. Tsirkin <mst@xxxxxxxxxx> > 发送时间: 2021年8月31日 22:34 > 收件人: Li,Rongqing <lirongqing@xxxxxxxxx> > 抄送: netdev@xxxxxxxxxxxxxxx; bpf@xxxxxxxxxxxxxxx; > virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx > 主题: Re: 答复: [PATCH] virtio_net: reduce raw_smp_processor_id() calling in > virtnet_xdp_get_sq > > On Tue, Aug 31, 2021 at 02:09:36AM +0000, Li,Rongqing wrote: > > > -----邮件原件----- > > > 发件人: Michael S. Tsirkin <mst@xxxxxxxxxx> > > > 发送时间: 2021年8月31日 5:10 > > > 收件人: Li,Rongqing <lirongqing@xxxxxxxxx> > > > 抄送: netdev@xxxxxxxxxxxxxxx; bpf@xxxxxxxxxxxxxxx; > > > virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx > > > 主题: Re: [PATCH] virtio_net: reduce raw_smp_processor_id() calling in > > > virtnet_xdp_get_sq > > > > > > On Thu, Aug 26, 2021 at 04:21:35PM +0800, Li RongQing wrote: > > > > smp_processor_id()/raw* will be called once each when not more > > > > queues in virtnet_xdp_get_sq() which is called in non-preemptible > > > > context, so it's safe to call the function > > > > smp_processor_id() once. > > > > > > > > Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx> > > > > > > commit log should probably explain why it's a good idea to replace > > > raw_smp_processor_id with smp_processor_id in the case of > > > curr_queue_pairs <= nr_cpu_ids. > > > > > > > > > I change it as below, is it ok? > > > > virtio_net: reduce raw_smp_processor_id() calling in > > virtnet_xdp_get_sq > > shorter: > > virtio_net: s/raw_smp_processor_id/smp_processor_id/ in virtnet_xdp_get_sq > > > > > > smp_processor_id() and raw_smp_processor_id() are called once > > each in virtnet_xdp_get_sq(), when curr_queue_pairs <= nr_cpu_ids, > > should be merged > > I'd just drop this part. > > > > > virtnet_xdp_get_sq() is called in non-preemptible context, so > > it's safe to call the function smp_processor_id(), and keep > > smp_processor_id(), and remove the calling of raw_smp_processor_id(), > > avoid the wrong use virtnet_xdp_get_sq to preemptible context > > in the future > > s/avoid.*/this way we'll get a warning if this is ever called in a preemptible > context/ > Thanks, should I resend it -Li > > > > > -Li
