On Mon, Mar 09, 2009 at 02:04:55PM +0000, James Bottomley wrote: > > Disadvantages: > > - UNMAP gets less testing > > Also disadvantages: UNMAP will not work unless trim is pulled back out > of libata again ... which makes this look a bit like a temporary hack. Huh? sd.c will continue to have sd_discard_fn() which will work fine for UNMAP. This will give us a different path for ATA discs and SCSI discs, as far as discard functions go. > As I've said before, I don't like the bio based approach. I think you > leak a page on every trim command doing it (why? because the kernel > mapped bios have special bio->end_io routines to collect and free the > pages, you have no such routine). I added that in an earlier patch: http://git.kernel.org/?p=linux/kernel/git/willy/ssd.git;a=commitdiff;h=f6ebf54cb8045a0cab19d73e26a07945c29d1394;hp=1223b373ae0283221b46e70955eb825679c5a6cb I'm all in favour of a less messy approach than using bios directly, if there is one. I don't see what it might look like yet. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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
