Ok, I think I figured out what was going on. The db->submit_transaction() call (from _txc_finish_io) was blocking when there was a submit_transaction_sync() in progress. This was making me hit a ceiling of about 80 iops on my slow disk. When I moved that into _kv_sync_thread (just prior to the submit_transaction_sync() call) it jumps up to 300+ iops. I pushed that to wip-newstore. Further, if I drop the O_DSYNC, it goes up another 50% or so. It'll take a bit more coding to effectively batch the (implicit) fdatasync from the O_DSYNC up, though, and capture some of that. Next! sage -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
