On 14.02.2008 [16:14:33 +0100], Julia Lawall wrote: > From: Julia Lawall <julia@xxxxxxx> > > 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@xxxxxxx> > > --- > > diff -u -p a/fs/direct-io.c b/fs/direct-io.c > --- a/fs/direct-io.c 2008-02-08 08:58:17.000000000 +0100 > +++ b/fs/direct-io.c 2008-02-13 20:58:53.000000000 +0100 > @@ -976,7 +976,7 @@ direct_io_worker(int rw, struct kiocb *i > for (seg = 0; seg < nr_segs; seg++) { > user_addr = (unsigned long)iov[seg].iov_base; > dio->pages_in_io += > - ((user_addr+iov[seg].iov_len +PAGE_SIZE-1)/PAGE_SIZE > + (DIV_ROUND_UP(user_addr + iov[seg].iov_len, PAGE_SIZE) > - user_addr/PAGE_SIZE); Is it just me, or does ((user_addr + iov[seg].iov_len + PAGE_SIZE - 1)/PAGE_SIZE - user_addr/PAGE_SIZE) not simplify to = ((iov[seg].iov_len + PAGE_SIZE - 1)/PAGE_SIZE + user_addr/PAGE_SIZE - user_addr/PAGE_SIZE) = ((iov[seg].iov_len + PAGE_SIZE - 1)/PAGE_SIZE) = DIV_ROUND_UP(iov[seg].iov_len, PAGE_SIZE) CMIIW. Thanks, Nish -- Nishanth Aravamudan <nacc@xxxxxxxxxx> IBM Linux Technology Center - To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
