Date:   Fri, 10 Mar 2023 13:47:38 -0800
From:   Eric Biggers <ebiggers@kernel.org>
To:     Al Viro <viro@zeniv.linux.org.uk>
Cc:     Yangtao Li <frank.li@vivo.com>, tytso@mit.edu,
        adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ext4: convert to DIV_ROUND_UP() in
 mpage_process_page_bufs()
Message-ID: <ZAulevdpZg/W/JbL@sol.localdomain>
References: <20230310060734.8780-1-frank.li@vivo.com>
 <ZArLbO1ckmcXwQf0@sol.localdomain>
 <20230310063729.GO3390869@ZenIV>
 <ZArRq/25a5Gt+YMB@sol.localdomain>
 <20230310064612.GQ3390869@ZenIV>
 <ZArULrNVaxl7e42r@sol.localdomain>
 <20230310070527.GS3390869@ZenIV>
 <20230310071231.GU3390869@ZenIV>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230310071231.GU3390869@ZenIV>
Precedence: bulk

On Fri, Mar 10, 2023 at 07:12:31AM +0000, Al Viro wrote:
> 
> Out of curiosity (and that's already too brittle for practical use) -
> does DIV_ROUND_UP_ULL() do any better on full example?

'DIV_ROUND_UP_ULL(i_size_read(inode), i_blocksize(inode))' works properly with
clang but not gcc.   If i_blocksize() is changed to do '1U << inode->i_blkbits'
instead of '1 << inode->i_blkbits', it works with gcc too.

- Eric