On Mon, Jun 4, 2012 at 12:15 PM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > On Fri, Jun 01, 2012 at 10:13:06AM +0100, Stefan Hajnoczi wrote: >> Other block drivers (cciss, rbd, nbd) use spin_unlock_irq() so I followed that. >> To me this seems wrong: blk_run_queue() uses spin_lock_irqsave() but we enable >> irqs with spin_unlock_irq(). If the caller of blk_run_queue() had irqs >> disabled and we enable them again this could be a problem, right? Can someone >> more familiar with kernel locking comment? > > Why take the risk? What's the advantage of enabling them here? VCPU is > not running while the hypervisor is processing the notification anyway. > And the next line returns from the function so the interrupts will get > enabled. I agree. After looking through the code more following Asias' call chain, I'm happy to use spin_unlock() and not worry about the irq part. Will fix. Stefan _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
