On Wed, Sep 4, 2013 at 8:08 AM, Jan Kara <jack@xxxxxxx> wrote: > On Thu 22-08-13 17:03:16, Andy Lutomirski wrote: >> Writes via mmap currently update mtime and ctime in ->page_mkwrite. >> This hurts both throughput and latency. In workloads that dirty a >> large number of mmapped pages, ->page_mkwrite can be hot and >> file_update_time is slow and scales poorly. Updating timestamps can >> also sleep, which hurts latency for real-time workloads. > It would help to make your case if you posted the latency comparison > before & after the patchset in this introductory email. We can then see > how significant is the reduction of latency... Will do, although the data from my workload will be a little strange. I was hoping that Dave Hansen would re-run his benchmark with these patches applied. I tried to run it, but it wasn't obvious what the numbers that spewed out meant. --Andy > > Honza > -- > Jan Kara <jack@xxxxxxx> > SUSE Labs, CR -- Andy Lutomirski AMA Capital Management, LLC -- 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
