On Thu, Apr 08, 2010 at 01:41:57PM -0700, john stultz wrote: > > I'll continue to play with your patch and see if I can con some some > folks with more interesting storage setups to do some testing as well. You might want to ask djwong to play with it with his nice big machine. (We don't need a big file system, but we want as many CPU's as possible, and to use his "mailserver" workload to really stress the journal. I'd recommend using barrier=0 for additional journal lock-level stress testing, and then try some forced sysrq-b reboots and then make sure that the filesystem is consistent after the journal replay.) I've since done basic two-CPU testing using xfstests under KVM, but that's really not going to test any locking issues. > Any thoughts for ways to rework the state_lock in start_this_handle? > (Now that its at the top of the contention logs? :) That's going to be much harder. We're going to have to take j_state_lock at some point inside start_this_handle. We might be able to decrease the amount of code which is run while the spinlock is taken, but I very much doubt it's possible to eliminate that spinlock entirely. Do you have detailed lockstat information showing the hold-time and wait-time of j_lock_stat (especially in start_this_handle)? - 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
