On Wed, 26 Aug 2009, Gleb Natapov wrote: > On Wed, Aug 26, 2009 at 10:42:05PM +0300, Avi Kivity wrote: > > On 08/26/2009 10:13 PM, Davide Libenzi wrote: > > >Ok, so why not using the eventfd counter as state? > > >On the device side: > > > > > >void write_state(int sfd, int state) { > > > u64 cnt; > > > > > > /* Clear the current state, sfd is in non-blocking mode */ > > > read(sfd,&cnt, sizeof(cnt)); > > > /* Writes new state */ > > > cnt = 1 + !!state; > > > write(sfd,&cnt, sizeof(cnt)); > > >} > > > > > > > > >On the hypervisor side: > > > > > >int read_state(int sfd) { > > > u64 cnt; > > > > > > read(sfd,&cnt, sizeof(cnt)); > > > return state - 1; > > >} > > > > > > > Hadn't though of read+write as set. While the 1+ is a little ugly, > > it's workable. > > > It's two system calls instead of one to inject interrupt. I guess that's going to completely throw off-chart your RT performance, doesn't it? - Davide -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html