From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934669AbbENAXr (ORCPT ); Wed, 13 May 2015 20:23:47 -0400 Received: from mail.kernel.org ([198.145.29.136]:48506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934608AbbENAXP (ORCPT ); Wed, 13 May 2015 20:23:15 -0400 Date: Wed, 13 May 2015 17:23:09 -0700 From: Jaegeuk Kim To: Arnd Bergmann Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Yossi Goldfill , linux-f2fs-devel@lists.sourceforge.net, Changman Lee Subject: Re: [PATCH] f2fs: fix building on 32-bit architectures Message-ID: <20150514002309.GB68412@jaegeuk-mac02> References: <2179770.3R5P5nr1c7@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2179770.3R5P5nr1c7@wuerfel> 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 Arnd, Thank you for the patch. Merged and pushed to -next. :) Thanks, On Wed, May 13, 2015 at 10:49:58PM +0200, Arnd Bergmann wrote: > A bug fix to the debug output extended the type of some local > variables to 64-bit, which now causes the kernel to fail building > because of missing 64-bit division functions: > > ERROR: "__aeabi_uldivmod" [fs/f2fs/f2fs.ko] undefined! > > In the kernel, we have to use div_u64 or do_div to do this, > in order to annotate that this is an expensive operation. > > As the function is only called for debug out, we know this > is not performance critical, so it is safe to use div_u64. > > Signed-off-by: Arnd Bergmann > Fixes: d1f85bd38db19 ("f2fs: avoid value overflow in showing current status") > --- > This patch is required for ARM allmodconfig builds. > > diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c > index efbc83f07305..75176e0dd6c8 100644 > --- a/fs/f2fs/debug.c > +++ b/fs/f2fs/debug.c > @@ -113,10 +113,10 @@ static void update_sit_info(struct f2fs_sb_info *sbi) > ndirty++; > } > } > - dist = MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec / 100; > - si->bimodal = bimodal / dist; > + dist = div_u64(MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec, 100); > + si->bimodal = div_u64(bimodal, dist); > if (si->dirty_count) > - si->avg_vblocks = total_vblocks / ndirty; > + si->avg_vblocks = div_u64(total_vblocks, ndirty); > else > si->avg_vblocks = 0; > }