On Wed, Mar 07 2001, Stephen C. Tweedie wrote: > > SCSI has ordered tag, which fit the model Alan described quite nicely. > > I've been meaning to implement this for some time, it would be handy > > for journalled fs to use such a barrier. Since ATA doesn't do queueing > > (at least not in current Linux), a synchronize cache is probably the > > only way to go there. > > Note that you also have to preserve the position of the barrier in the > elevator queue, and you need to prevent LVM and soft raid from > violating the barrier if different commands end up being sent to > different disks. Yep, it's much harder than it seems. Especially because for the barrier to be really useful, having inter-request dependencies becomes a requirement. So you can say something like 'flush X and Y, but don't flush Y before X is done'. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
- Re: scsi vs ide performance on fs... Jeremy Hansen
- Re: scsi vs ide performance o... Linus Torvalds
- Re: scsi vs ide performance o... Stephen C. Tweedie
- Re: scsi vs ide performance on fsync's David Balazic
- Re: scsi vs ide performance on fsync's Gregory Maxwell
- Re: scsi vs ide performance on fsync's Jonathan Morton
- Re: scsi vs ide performance on fsync's Mark Hahn
- Re: scsi vs ide performance on fsync's David Balazic
- Re: scsi vs ide performance on fsync's Jens Axboe
- Re: scsi vs ide performance on fsync's Stephen C. Tweedie
- Re: scsi vs ide performance on fsync's Jens Axboe
- Re: scsi vs ide performance on fsync's Stephen C. Tweedie
- Re: scsi vs ide performance on fs... Jens Axboe
- Re: scsi vs ide performance o... Stephen C. Tweedie
- Re: scsi vs ide performance o... Jens Axboe
- Re: scsi vs ide performance o... Stephen C. Tweedie
- Re: scsi vs ide performance o... Jens Axboe
- Re: scsi vs ide performance o... Chris Mason
- Re: scsi vs ide performance on fsync's David Balazic
- Re: scsi vs ide performance on fsync's Matthias Urlichs
- Re: scsi vs ide performance on fsync's Jens Axboe