Hello! On Wed 30-03-16 18:19:23, Jan Kara wrote: > this is a second version of the patches to fix data exposure after a crash > in data=ordered mode. Since previous revision I have implemented suggestion > by Ted that it is enough to wait for outstanding writeback from jbd2 thread > when IO was already submitted during delalloc writeback (see patches 3 and > 4 for details). > > I have checked that indeed jbd2 did not submit any data buffers under > appropriate load (I've used randwrite workload from fio) with the improvement > but I didn't observe any measurable improvement in transaction commit times > - waiting for already outstanding writeback was dominating the commit time and > the additional buffers jbd2 was originally submitting apparently didn't make > a big difference. At least for this workload. I have a hard time coming up with > some other workload where the optimization would make a big difference since > flusher thread ends up submitting overwritten blocks anyway which makes jbd2 > thread wait for the IO. But still conceptually the change makes sense so it > may be worth it. So Ted, feel free to either merge or drop the last two > patches in this series... Ping Ted? It would be good to merge at least the first patch in the series during this cycle... Thanks! Honza -- Jan Kara <jack@xxxxxxxx> 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
