On 05/09/2014 03:17 AM, Matias Bjørling wrote: > With multi-million IOPS and multi-node workloads, the atomic_t in_flight > tracking becomes a bottleneck. Change the in-flight accounting to per-cpu > counters to elevate.
The part stats are a pain in the butt, I've tried to come up with a great fix for them too. But I don't think the percpu conversion is necessarily the right one. The summing is part of the hotpath, so percpu counters aren't necessarily the right way to go. I don't have a better answer right now, otherwise it would have been fixed :-) There's some low hanging fruit (like doing part_in_flight() twice in part_round_stats_single()), though. So I'm not going to apply this one as-is, lets see if we can find a better solution. Perhaps local_t would be a good solution. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
