On Wed, Jun 25 2008, Matthew Wilcox wrote: > On Wed, Jun 25, 2008 at 07:26:39PM +0200, Jens Axboe wrote: > > Uhm, but it IS "a blatant layering violation", it's doing things from > > the wrong side up :-) > > That's just "doing things from a spot Jens doesn't approve of". A > layering violation would be SCSI knowing how elevators work. And that's what the patch is doing, it knows that CFQ/AS idles and thus chooses noop. So it's even doing it wrong, since that disables other goodness as well. The whole sd_set_elevator() is a mess, I honestly can't see how you can even start to defend it. I don't really appreciate the personal bit either. > > I don't think udev is a particularly good idea either. My plan was to > > introduce device profiles for the queue, but it is probably a bad idea > > to over-engineer this. So I'll keep it simple, stick to a 'zero cost > > seek' flag instead and allow drivers to signal that. libata/ide needs to > > check the ID page word to detect SSD drives as well, so they need a few > > lines of change too. > > One of the other patches in this mess was the libata piece to translate > ATA8's rotation speed to SCSI's b1 VPD page, so ide is the only > remaining work left to do (can't it die already?) IDE is definitely low priority :-). I had a pata ssd drive, but IDE is only really interesting for the bits that can't be libata driven. So not very interesting. ATA8 seems to have changed the SSD detection scheme. I don't have an SSD disk so I cannot check what the current models report. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
