2020-12-13 14:18:27

by Lukas Bulwahn

Subject: [PATCH v3] block: drop dead assignments in loop_init()

Commit 8410d38c2552 ("loop: use __register_blkdev to allocate devices on
demand") simplified loop_init(); so computing the range of the block region
is not required anymore and can be dropped.

Drop dead assignments in loop_init().

As compilers will detect these unneeded assignments and optimize this,
the resulting object code is identical before and after this change.

No functional change. No change in object code.

Signed-off-by: Lukas Bulwahn <[email protected]>
---
v1 -> v2:
- replaced if block with ternary operator after Julia's style comment

v2 -> v3:
- use if instead of ternary following Jens' preference

Christoph, please ack.

Jens, please pick this minor non-urgent clean-up patch on your
block -next tree on top of Christoph's commit above.


drivers/block/loop.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d2ce1ddc192d..e5ff328f0917 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2304,7 +2304,6 @@ MODULE_ALIAS("devname:loop-control");
static int __init loop_init(void)
{
int i, nr;
- unsigned long range;
struct loop_device *lo;
int err;

@@ -2341,13 +2340,10 @@ static int __init loop_init(void)
* /dev/loop-control interface, or be instantiated by accessing
* a 'dead' device node.
*/
- if (max_loop) {
+ if (max_loop)
nr = max_loop;
- range = max_loop << part_shift;
- } else {
+ else
nr = CONFIG_BLK_DEV_LOOP_MIN_COUNT;
- range = 1UL << MINORBITS;
- }

err = misc_register(&loop_misc);
if (err < 0)
--
2.17.1

2020-12-14 06:04:54

by Jens Axboe

Subject: Re: [PATCH v3] block: drop dead assignments in loop_init()

On 12/11/20 10:13 PM, Lukas Bulwahn wrote:
> Commit 8410d38c2552 ("loop: use __register_blkdev to allocate devices on
> demand") simplified loop_init(); so computing the range of the block region
> is not required anymore and can be dropped.
>
> Drop dead assignments in loop_init().
>
> As compilers will detect these unneeded assignments and optimize this,
> the resulting object code is identical before and after this change.
>
> No functional change. No change in object code.

Applied, thanks.

--
Jens Axboe