hi all: I read the function of process_backlog, and I found it don't delete the NIC form poll list. the codes is: 4321 static int process_backlog(struct napi_struct *napi, int quota) 4322 { 4323 int work = 0; 4324 struct softnet_data *sd = container_of(napi, struct softnet_data, backlog); 4325 4326 /* Check if we have pending ipi, its better to send them now, 4327 * not waiting net_rx_action() end. 4328 */ 4329 if (sd_has_rps_ipi_waiting(sd)) { 4330 local_irq_disable(); 4331 net_rps_action_and_irq_enable(sd); 4332 } 4333 4334 napi->weight = weight_p; 4335 local_irq_disable(); 4336 while (1) { 4337 struct sk_buff *skb; 4338 4339 while ((skb = __skb_dequeue(&sd->process_queue))) { 4340 local_irq_enable(); 4341 __netif_receive_skb(skb); 4342 local_irq_disable(); 4343 input_queue_head_incr(sd); 4344 if (++work >= quota) { 4345 local_irq_enable(); 4346 return work; 4347 } 4348 } 4349 4350 rps_lock(sd); 4351 if (skb_queue_empty(&sd->input_pkt_queue)) { 4352 /* 4353 * Inline a custom version of __napi_complete(). 4354 * only current cpu owns and manipulates this napi, 4355 * and NAPI_STATE_SCHED is the only possible flag set 4356 * on backlog. 4357 * We can use a plain write instead of clear_bit(), 4358 * and we dont need an smp_mb() memory barrier. 4359 */ 4360 napi->state = 0; 4361 rps_unlock(sd); 4362 4363 break; 4364 } 4365 4366 skb_queue_splice_tail_init(&sd->input_pkt_queue, 4367 &sd->process_queue); 4368 rps_unlock(sd); 4369 } 4370 local_irq_enable(); 4371 4372 return work; 4373 } I think we should delete the NIC from the poll list by: list_del(&napi->poll_list); and my git repository infromation is: [root@localhost linux]# git show commit aa39477b5692611b91ac9455ae588738852b3f60 Merge: 48ec833 5164bec Author: Linus Torvalds <torvalds@linux-foundation.org> Date: Mon Dec 22 14:47:17 2014 -0800 Merge tag 'dm-3.19-fixes' of git:// git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: "Thre stable fixes and one fix for a regression introduced during 3.19 merge: - Fix inability to discard used space when the thin-pool target is in out-of-data-space mode and also transition the thin-pool back to write mode once free space is made available. - Fix DM core bio-based end_io bug that prevented proper post-processing of the error code returned from the block layer. - Fix crash in DM thin-pool due to thin device being added to the pool's active_thins list before properly initializing the thin device's refcount" * tag 'dm-3.19-fixes' of git:// git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: fix missed error code if .end_io isn't implemented by target_type dm thin: fix crash by initializing thin device's refcount and completion earlier dm thin: fix missing out-of-data-space to write mode transition if blocks are released dm thin: fix inability to discard blocks when in out-of-data-space mode Don't handle the list_del is right, or this is a bug? Thank you.