Am 19.05.2010 um 10:18 schrieb Peter Lieven: > Kevin Wolf wrote: >> Am 19.05.2010 09:29, schrieb Christoph Hellwig: >> >>> On Tue, May 18, 2010 at 03:22:36PM +0200, Kevin Wolf wrote: >>> >>>> I think it's stuck here in an endless loop: >>>> >>>> while (laiocb->ret == -EINPROGRESS) >>>> qemu_laio_completion_cb(laiocb->ctx); >>>> >>>> Can you verify this by single-stepping one or two loop iterations? ret >>>> and errno after the read call could be interesting, too. >>>> >>> Maybe the compiler is just too smart. Without some form of barrier >>> it could just optimize the loop away as laiocb->ret couldn't change >>> in a normal single-threaded environment. >>> >> >> It probably could in theory, but in practice we're in a read() inside >> qemu_laio_completion, so it didn't do it here. >> > if you supply a patch that will add some usleeps at the point in > question i'm willing to test if it solves the 100% cpu problem. can someone help here? what would be the best option to add some usleeps? >> Kevin >> >> > > > -- 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
