Jeff Garzik wrote: > Carlo Wood wrote: >> The dmesg output of 33480a0ede8dcc7e6483054279008f972bd56fd3 (thus >> "before") is: > [...] >> And the dmesg output of 551c012d7eea3dc5ec063c7ff9c718d39e77634f (thus >> "after") is: > [...] > > Your disk configurations are quite radically different between the two > kernels (see attached diff for key highlights). > > The new behavior of the more recent kernel (551c012d7...) is that it now > fully drives your hardware :) The reset problems go away, NCQ is > enabled, and if you had 3.0Gbps drives (you don't) they would be driven > at a faster speed. > > Given that some drives might be better tuned for benchmarks in > non-queued mode, and that a major behavior difference is that your > drives are now NCQ-enabled, the first thing I would suggest you try is > disabling NCQ: > http://linux-ata.org/faq.html#ncq > > Other indicators are the other changes in the "ahci 0000:00:1f.2: > flags:" line, which do affect other behaviors, though none so important > to RAID5 performance as NCQ, I would think. > > Turning on NCQ also potentially affects barrier behavior in RAID, though > I'm guessing that is not a factor here. Ah.. right. That should have enabled NCQ. Me slow today. :-) -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
