On Tue, Jan 09 2007, Neil Brown wrote: > On Monday January 8, akpm@xxxxxxxx wrote: > > On Mon, 8 Jan 2007 10:08:34 +0100 > > Lars Ellenberg <Lars.Ellenberg@xxxxxxxxxx> wrote: > > > > > md raidX make_request functions strip off the BIO_RW_SYNC flag, > > > thus introducing additional latency. > > > > > > fixing this in raid1 and raid10 seems to be straight forward enough. > > > > > > for our particular usage case in DRBD, passing this flag improved > > > some initialization time from ~5 minutes to ~5 seconds. > > > > That sounds like a significant fix. > > > > This patch also applies to 2.6.19 and I have tagged it for a -stable > > backport. Neil, are you OK with that? > > Yes, I'm OK with that, thanks. Ack from me as well, it's really a quite nasty bug from a performance POV. Not just for DRDB, but for io schedulers as well. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
