From: Julia Lawall <julia at diku.dk> 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 <julia at diku.dk> --- 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);
Mark Fasheh
2008-Feb-18 11:36 UTC
[Ocfs2-devel] 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 <julia@diku.dk> > > 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 <julia@diku.dk>Acked-by: Mark Fasheh <mark.fasheh@oracle.com> --Mark -- Mark Fasheh Principal Software Developer, Oracle mark.fasheh@oracle.com