On Fri, Jul 30, 2010 at 05:09:52PM +0400, Vladislav Bolkhovitin wrote: > Sorry, I can't follow you here. What was the load pattern difference > between the tests in the way how the backend device saw it? I thought, > it was only in absence of the cache flush commands (SYNCHRONIZE_CACHE?) > in the write through case, but looks like there is something more different? The only difference in commands is that we see no SYNCHRONIZE_CACHE. The big picture difference is that we also only drain the queue just to undrain it ASAP, instead of keeping it drained over a sequence of SYNCHRONIZE_CACHE + WRITE + SYNCHRONIZE_CACHE, which can make a huge difference for a device with very low latencies like the SSD in my laptop. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
