From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756257Ab0I1Tew (ORCPT ); Tue, 28 Sep 2010 15:34:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52722 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753850Ab0I1Tev (ORCPT ); Tue, 28 Sep 2010 15:34:51 -0400 Date: Tue, 28 Sep 2010 15:34:46 -0400 From: Vivek Goyal To: linux kernel mailing list , Jens Axboe Cc: Randy Dunlap Subject: [PATCH] blkio-throttle: Fix linux-next compilation failure on i386 Message-ID: <20100928193446.GE8950@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jens, One more fix for throttling logic. After this fix I realized that there is potential for integer overflow in my calculations. I need to figure out how to take care of these overflow situations and will post a patch for that later. Thanks Vivek o Randy Dunlap reported following linux-next failure. This patch fixes it. on i386: blk-throttle.c:(.text+0x1abb8): undefined reference to `__udivdi3' blk-throttle.c:(.text+0x1b1dc): undefined reference to `__udivdi3' o bytes_per_second interface is 64bit and I was continuing to do 64 bit division even on 32bit platform without help of special macros/functions hence the failure. Signed-off-by: Vivek Goyal --- block/blk-throttle.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) Index: linux-2.6-block/block/blk-throttle.c =================================================================== --- linux-2.6-block.orig/block/blk-throttle.c 2010-09-28 12:42:51.000000000 -0400 +++ linux-2.6-block/block/blk-throttle.c 2010-09-28 14:16:05.000000000 -0400 @@ -378,7 +378,8 @@ throtl_slice_used(struct throtl_data *td static inline void throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw) { - unsigned long nr_slices, bytes_trim, time_elapsed, io_trim; + unsigned long nr_slices, time_elapsed, io_trim; + u64 bytes_trim, tmp; BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw])); @@ -396,8 +397,10 @@ throtl_trim_slice(struct throtl_data *td if (!nr_slices) return; + tmp = tg->bps[rw] * throtl_slice * nr_slices; + do_div(tmp, HZ); + bytes_trim = tmp; - bytes_trim = (tg->bps[rw] * throtl_slice * nr_slices)/HZ; io_trim = (tg->iops[rw] * throtl_slice * nr_slices)/HZ; if (!bytes_trim && !io_trim) @@ -415,7 +418,7 @@ throtl_trim_slice(struct throtl_data *td tg->slice_start[rw] += nr_slices * throtl_slice; - throtl_log_tg(td, tg, "[%c] trim slice nr=%lu bytes=%lu io=%lu" + throtl_log_tg(td, tg, "[%c] trim slice nr=%lu bytes=%llu io=%lu" " start=%lu end=%lu jiffies=%lu", rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim, tg->slice_start[rw], tg->slice_end[rw], jiffies); @@ -462,7 +465,7 @@ static bool tg_with_in_bps_limit(struct struct bio *bio, unsigned long *wait) { bool rw = bio_data_dir(bio); - u64 bytes_allowed, extra_bytes; + u64 bytes_allowed, extra_bytes, tmp; unsigned long jiffy_elapsed, jiffy_wait, jiffy_elapsed_rnd; jiffy_elapsed = jiffy_elapsed_rnd = jiffies - tg->slice_start[rw]; @@ -473,8 +476,9 @@ static bool tg_with_in_bps_limit(struct jiffy_elapsed_rnd = roundup(jiffy_elapsed_rnd, throtl_slice); - bytes_allowed = (tg->bps[rw] * jiffies_to_msecs(jiffy_elapsed_rnd)) - / MSEC_PER_SEC; + tmp = tg->bps[rw] * jiffies_to_msecs(jiffy_elapsed_rnd); + do_div(tmp, MSEC_PER_SEC); + bytes_allowed = tmp; if (tg->bytes_disp[rw] + bio->bi_size <= bytes_allowed) { if (wait)