On Tue, Jul 04, 2017 at 05:27:02PM +0900, Damien Le Moal wrote: > The BIO issuing loop in __blkdev_issue_zeroout() is allocating BIOs > with a maximum number of bvec (pages) equal to > > min(nr_sects, (sector_t)BIO_MAX_PAGES) > > This works since the BIO will always be limited to the absolute maximum > number of pages but this is ineficient as too many bvec entries may be > requested since different units (number of sectors vs number of pages) > are used in the min() operation. Fix this by correctly using the same > unit (number of pages), making sure that this number is at least 1 for > cases where the number of sectors is less that the number of sectors in > a page. > > Also remove a trailing space after the bit shift in the internal loop > min() call. Can you move the nr sectors calculation into a helper and add some comments?
