On Mon, Mar 25, 2013 at 11:24:11AM +0100, Lukas Czerner wrote: > Currently on many places in ext4 we're using > ext4_get_group_no_and_offset() even though we're only interested in > knowing the block group of the particular block, not the offset within > the block group so we can use more efficient way to compute block group. > > This patch introduces ext4_get_group_number() which computes block group > for a givem block much more efficiently. Use this function instead of > ext4_get_group_no_and_offset() everywhere where we're only interested in > knowing the block group. Again, we have the same problem as the previous patch. I could imagine setting a flag which uses the shift-instead-of-div optimization, but that will reduce the optimization somewhat. OTOH, an 64-bit division is pretty expensive, especially on older/simpler CPU's, so perhaps it's worth it. - Ted -- 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
