On Wed 30-01-13 00:26:58, Ted Tso wrote: > On Wed, Jan 23, 2013 at 08:29:11PM +0100, Jan Kara wrote: > > > old JBD: AIM7 jobs/min 97624.39; got 78193 jbd wakeups > > > new JBD: AIM7 jobs/min 85929.43; got 6306999 jbd wakeups, 6264684 extra wakeups > > Yeah, that's a lot. My guess would be *a lot* of processes are hanging in > > start_this_handle() and waiting for transaction commit. Each of them calls > > __log_start_commit() and things add up. Thanks for getting these numbers. > > Yeah, wow. That would imply that there are a huge number of processes > that get hung up in start_this_handle(), and they are waking up the > journal before the kjournald has a chance to set T_LOCKED (since then > they would get blocked earlier in start_this_handle). > > Given that, I wonder if the following change would actually help or > hurt things. Eric, would you be willing to ask your perf team to try > testing out these patches? Umm, I don't see anything. Forgot to attach them? Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- 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
