On Mon, May 11, 2009 at 6:48 AM, Matthew Wilcox <matthew@xxxxxx> wrote: > > On Mon, May 11, 2009 at 02:43:25PM +0200, J??rn Engel wrote: > > Given the hardware braindamage it is relatively sane. As always, it > > would be much better to fix the problem and not add workarounds, but we > > seem to lack the gods favor this time around. > > > > Can't anyone explain to the SATA folks that a discard is much closer to > > a write than to a secure erase or some other rare and slow command? > > I've heard the ATA committee are working on an NCQ version of TRIM. Doesn't this fact make this discussion moot? If the ATA committee knows they've got a problem, and are fixing it at the level where the problem exists, why is Linux's job to fix at a higher level? The proposed solutions are going to consume CPU and slow down I/O unnecessarily, as well as inefficiently dispatch Discards (i.e. the longer the time between the discard and the reuse of a block, the better). If they are going to be implemented, then have a special "brain-dead ATA mode" that doesn't inhibit solutions that can implement Discard w/o the "queue draining" required by the broken implementation. Chris P.S. Why was ext2/discard functionality removed? -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
