Hello, On 08/17/2010 03:23 PM, Christoph Hellwig wrote: >> Hmmm... the underlying storage could be md/dm RAIDs in which case FUA >> should be cheaper than FLUSH. > > If someone ever wrote a virtio-blk backend that sits directly ontop > of the Linux block layer that would be true. Of the five known > virtio-blk backends all operate on normal files using the Posix I/O > APIs, or the Linux aio API (optionally in qemu) or in-kernel > vfs_read/vfs_write (vhost-blk). Right. > Given how little testing lguest gets compared to qemu I really don't > want a protocol addition for it unless it really buys us something. > Once we're done with this barrier conversion I plan into benchmarking > FUA and a pre-flush tag on the command for virtio in real life setups, > and see if it actually buys us anything. Hmmm... yeah, we can drop it. Michael, what do you think? Thanks. -- tejun -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
