On Wed, Dec 10, 2014 at 09:59:12PM +0900, Akira Hayakawa wrote: > Joe, > > I appreciate your continuous work. > > Is that read or write? > The difference between Type 0 and 1 should only show up in write path. > So is it write test? Yes, writing across the whole device using 'dd'. These are the tests: dmtest list --suite writeboost -n /wipe_device/ > And what is the unit of each result? seconds. > > > So maybe it's just volume of IO that's causing the problem? What's > > the difference between Type 0 and Type 1? In the code I notice you > > have 'rambuf' structures, are you caching IO in memory? > "rambuf" is a temporary space that every write data comes in. > 127*4KB data are once stored there and 4KB metadata section are added > then it becomes a log and flushed to the cache device sequentially (512KB each). So you copy the bio payload to a different block of ram and then complete the bio? Or does the rambuf refer to the bio payload directly? > By the way, > I think more clearer discussion can be done if tests are done on physical machines > to isolate things relevant to VM. I will also add these tests to dmts later and > run on my machine. > But, it will be much better if we have good server with RAID-ed backing store > and the newest SSD (How would it be if it's PCI-e SSD)... I generally find it quicker to investigate problems on the machine that are actually exhibiting the problem ;) Seriously though, you're asking us to send this upstream; it needs to work on consumer level hardware. I've got a big machine with Fusion IO storage that I can run the same tests on later. - Joe -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
