On Tue, Nov 30, 2010 at 11:39:06AM +1100, Neil Brown wrote: > Would it not be sufficient to simply gather flushes while a flush is pending. > i.e > - if no flush is pending, set the 'flush pending' flag, submit a flush, > then clear the flag. > - if a flush is pending, then wait for it to complete, and then submit a > single flush on behalf of all pending flushes. > > That way when flush is fast, you do a flush every time, and when it is slow > you gather multiple flushes together. We can even optimize the second flush away if no other I/O has completed since the first flush has started. That will always be the case for SATA devices as the cache flush command is not queued. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
