On Wed, Dec 10, 2008 at 12:50:17PM -0600, Anthony Liguori wrote: > But opening twice means that you lose coherency with NFS.
Not sure why. They're not running from different nfs clients. If this really isn't feasible, other ways to go would be to stick with a single thread and add kernel aio to fix seeking I/O bandwidth (so cfq indexing the bucket by the thread id will also work ok). Alternatively we can support readv/writev only with kernel aio, no threads, and we emulate it with a flood of pread/pwrite on the other host os plus we set DEBUG_BOUNCE where readv/writev is emulated. But then linux will be the only host OS benefiting from zerocopy. If we never want to add kernel aio, we can also add preadv/pwritev to linux but it remains a linux-only solution, so going with kernel aio for a linux-only solution is surely better than the workaround with userland threads plus preadv/pwritev. Still Al or somebody should add preadv/pwritev, those are needed and useful as shown here. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
