On Wed, Mar 02, 2016 at 10:15:02AM +0100, Arnd Bergmann wrote: > I'm missing the background on this, just saw the patch fly by, > so sorry if this has been asked before: > > Why do you want to invalidate the cache? Is this to save RAM > or is something else going to write here and you have to invalidate > it for correctness?
BLKZEROOUT can be though as a direct I/O operation - it issues a WRITE SAME (or similar) command straight to the device to zero the specified range. If there was cached data for this range it would now be stale.
