On Fri, Jul 12, 2013 at 08:13:36AM +0200, Stefan Priebe - Profihost AG wrote: > Am 12.07.2013 03:55, schrieb Kent Overstreet: > > On Thu, Jul 04, 2013 at 10:13:20AM +0200, Stefan Priebe - Profihost AG wrote: > >> Hello list, > >> > >> while testing bcache i noticed that while writing a big 48GB file the > >> sequential cutoff works fine i see only I/O on the disk but not on the > >> cache. I thought i would afterwards see a bypassed value of around 48GB > >> but it is only 1.2GB. > >> > >> Is this expected? Is bcache in kernel 3.10 stable for production usage? > > > > That sounds like a bug, but bcache in 3.10 certainly should be stable > > for production usage. > > > > There can be some weirdness due to the way the stats work, there's a ~13 > > second update interval (and also the intermediate counters are 32 bit > > ints so if you manage to wrap that in 13 seconds you'll lose counts, but > > it's counting sectors so I doubt that happened here). > > Mhm i doubt that too. But if i write 40GB shouldn't i see a bypass value > near 40GB? It's just very small. > > > Does that sound like it might explain what you were seeing, or do you > > think there's something else going on? > No right no i don't believe that. Have you noticed any pattern to it? Does it appear to sometimes be right and sometimes wrong, or is it always wrong? I looked again at the code that updates that value and I'm not coming up with any ideas to explain what you're seeing... -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
