On Thu, Dec 11, 2008 at 04:53:35PM +0100, Andrea Arcangeli wrote: > > * It can't handle block allocation. Kernel handles that by doing > > such writes synchronously via VFS layer (instead of the separate > > aio code paths). Leads to horrible performance and bug reports > > such as "installs on sparse files are very slow". > > I think here you mean O_DIRECT regardless of aio/sync API, I doubt aio > has any relevance to block allocation in any way, so whatever problem > we have with kernel API and O_DIRECT should also be there with > sync-api + userland threads and O_DIRECT.
userland threads with O_DIRECT means only the thread doing block allocation gets stalled, not any other. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
