On Thu, Jun 02, 2011 at 08:54:03PM -0400, Vivek Goyal wrote: > > In this case I had done "sync" while aio-stress was doing O_DIRECT writes. > I really don't have any real world example, I just cooked up a hypothetical > scenario. > > Just wondering why ext4 and XFS behavior are different and which is a > more appropriate behavior. ext4 does not seem to be waiting for all > pending AIO/DIO to finish while XFS does. I think this is something we can chalk up to "different implementations do different things". I'm not convinced either behviour is wrong per se. Granted, the recent work to make sync and fsync not livelock in the face of continuing writes means that I'm more happy with ext4's behaviour, but I don't think that means xfs's behavior is wrong. One of the things that I have thought about is sysctl which makes sync a no-op unless you are root. The reason for that is that many system administrators sometimes have a habit of typing sync, and on a heavily loaded production server, this can really cause performance to go to hell for up to tens of minutes. So it might make sense to not allow non-root users from trashing overall system performance by running sync.... - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
