Hello, On Tue, Sep 01, 2015 at 02:51:50PM +0200, Michal Hocko wrote: > > Is reclaim throughput as determined by CPU cycle bandwidth a > > meaningful metric? > > Well, considering it has a direct effect on the latency I would consider > it quite meaningful. > > > I'm having a bit of trouble imagining that this > > actually would matter especially given that writeback is single > > threaded per bdi_writeback. > > Sure, if the LRU contains a lot of dirty pages then the writeback will be > a bottleneck. But LRUs are quite often full of the clean pagecache pages > which can be reclaimed quickly and efficiently. I see. Hmmm... I can imagine the scheduling latencies from synchronization being a factor. Alright, if we decide to do this return-path reclaiming, I'll update the patch to accumulate nr_pages. Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>