Re: [Xen-devel] [PATCH net v2 2/3] xen-netback: don't stop dealloc kthread too early
From: Wei Liu <hidden>
Date: 2014-08-11 14:44:42
On Mon, Aug 11, 2014 at 03:13:41PM +0100, Zoltan Kiss wrote: [...]
quoted hunk ↗ jump to hunk
quoted
And cleaning it up a bit (the while() could be a for(;;)).I would recommend this: ---@@ -2066,7 +2066,7 @@ int xenvif_dealloc_kthread(void *data) wait_event_interruptible(queue->dealloc_wq, tx_dealloc_work_todo(queue) || kthread_should_stop()); - if (kthread_should_stop()) + if (kthread_should_stop() && !atomic_read(&queue->inflight_packets)) break; xenvif_tx_dealloc_action(queue);--- If kthread_stop called, this will keep the main loop running until all callbacks are called. Then it proceeds to the exit branch, otherwise doesn't disrupt normal operation.
This snippet lacks change to while(). I would generally go for a shorter solution if the code is self-explanatory.
@@ -2078,21 +2066,19 @@ int xenvif_dealloc_kthread(void *data) { struct xenvif_queue *queue = data; - while (!kthread_should_stop()) { + for (;;) { wait_event_interruptible(queue->dealloc_wq, tx_dealloc_work_todo(queue) || kthread_should_stop()); - if (kthread_should_stop()) + if (kthread_should_stop() && + !atomic_read(&queue->inflight_packets) && + !tx_dealloc_work_todo(queue)) break; xenvif_tx_dealloc_action(queue); cond_resched(); } - /* Unmap anything remaining*/ - if (tx_dealloc_work_todo(queue)) - xenvif_tx_dealloc_action(queue); - return 0; }