2008-02-14 15:15:46

by Julia Lawall

Subject: [PATCH 3/6] fs/ocfs2: Use DIV_ROUND_UP

From: Julia Lawall <[email protected]>

The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) /
(d)) but is perhaps more readable.

An extract of the semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@haskernel@
@@

#include <linux/kernel.h>

@depends on haskernel@
expression n,d;
@@

(
- (n + d - 1) / d
+ DIV_ROUND_UP(n,d)
|
- (n + (d - 1)) / d
+ DIV_ROUND_UP(n,d)
)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP((n),d)
+ DIV_ROUND_UP(n,d)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP(n,(d))
+ DIV_ROUND_UP(n,d)
// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---

diff -u -p a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
--- a/fs/ocfs2/cluster/heartbeat.c 2007-12-31 08:43:31.000000000 +0100
+++ b/fs/ocfs2/cluster/heartbeat.c 2008-02-13 20:59:54.000000000 +0100
@@ -1149,7 +1149,7 @@ static int o2hb_map_slot_data(struct o2h
slot->ds_raw_block = NULL;
}

- reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp;
+ reg->hr_num_pages = DIV_ROUND_UP(reg->hr_blocks, spp);
mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks "
"at %u blocks per page\n",
reg->hr_num_pages, reg->hr_blocks, spp);

2008-02-18 19:36:40

by Mark Fasheh

Subject: Re: [PATCH 3/6] fs/ocfs2: Use DIV_ROUND_UP

On Thu, Feb 14, 2008 at 04:15:17PM +0100, Julia Lawall wrote:
> From: Julia Lawall <[email protected]>
>
> The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) /
> (d)) but is perhaps more readable.
>
> An extract of the semantic patch that makes this change is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
>
> // <smpl>
> @haskernel@
> @@
>
> #include <linux/kernel.h>
>
> @depends on haskernel@
> expression n,d;
> @@
>
> (
> - (n + d - 1) / d
> + DIV_ROUND_UP(n,d)
> |
> - (n + (d - 1)) / d
> + DIV_ROUND_UP(n,d)
> )
>
> @depends on haskernel@
> expression n,d;
> @@
>
> - DIV_ROUND_UP((n),d)
> + DIV_ROUND_UP(n,d)
>
> @depends on haskernel@
> expression n,d;
> @@
>
> - DIV_ROUND_UP(n,(d))
> + DIV_ROUND_UP(n,d)
> // </smpl>
>
> Signed-off-by: Julia Lawall <[email protected]>
Acked-by: Mark Fasheh <[email protected]>
--Mark

--
Mark Fasheh
Principal Software Developer, Oracle
[email protected]