From: Changbin Du <changbin.du@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
David Sterba <dsterba@suse.com>,
Changbin Du <changbin.du@gmail.com>,
Anand Jain <anand.jain@oracle.com>,
Nikolay Borisov <nborisov@suse.com>,
Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>,
Qu Wenruo <wqu@suse.com>, Gu Jinxiang <gujx@cn.fujitsu.com>,
linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] btrfs: avoid link error with CONFIG_NO_AUTO_INLINE
Date: Mon, 5 Nov 2018 14:37:18 +0000 [thread overview]
Message-ID: <20181105143717.xrarjgcdgaipmsqd@mail.google.com> (raw)
In-Reply-To: <20181103153941.1881966-1-arnd@arndb.de>
Thanks for this fix.
Reviewed-by: Changbin Du <changbin.du@gmail.com>
On Sat, Nov 03, 2018 at 04:39:28PM +0100, Arnd Bergmann wrote:
> On 32-bit ARM with gcc-8, I see a link error with the addition of the
> CONFIG_NO_AUTO_INLINE option:
>
> fs/btrfs/super.o: In function `btrfs_statfs':
> super.c:(.text+0x67b8): undefined reference to `__aeabi_uldivmod'
> super.c:(.text+0x67fc): undefined reference to `__aeabi_uldivmod'
> super.c:(.text+0x6858): undefined reference to `__aeabi_uldivmod'
> super.c:(.text+0x6920): undefined reference to `__aeabi_uldivmod'
> super.c:(.text+0x693c): undefined reference to `__aeabi_uldivmod'
> fs/btrfs/super.o:super.c:(.text+0x6958): more undefined references to `__aeabi_uldivmod' follow
>
> So far this is the only file that shows the behavior, so I'd propose
> to just work around it by marking the functions as 'static inline'
> that normally get inlined here.
>
> The reference to __aeabi_uldivmod comes from a div_u64() which has an
> optimization for a constant division that uses a straight '/' operator
> when the result should be known to the compiler. My interpretation is
> that as we turn off inlining, gcc still expects the result to be constant
> but fails to use that constant value.
>
> Cc: Changbin Du <changbin.du@gmail.com>
> Fixes: 943b8435c3bd ("kernel hacking: add a config option to disable compiler auto-inlining")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> fs/btrfs/super.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index c3c1e7bee49d..b7af0b8936ad 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -1922,7 +1922,7 @@ static int btrfs_remount(struct super_block *sb, int *flags,
> }
>
> /* Used to sort the devices by max_avail(descending sort) */
> -static int btrfs_cmp_device_free_bytes(const void *dev_info1,
> +static inline int btrfs_cmp_device_free_bytes(const void *dev_info1,
> const void *dev_info2)
> {
> if (((struct btrfs_device_info *)dev_info1)->max_avail >
> @@ -1951,8 +1951,8 @@ static inline void btrfs_descending_sort_devices(
> * The helper to calc the free space on the devices that can be used to store
> * file data.
> */
> -static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
> - u64 *free_bytes)
> +static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
> + u64 *free_bytes)
> {
> struct btrfs_device_info *devices_info;
> struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
> --
> 2.18.0
>
--
Thanks,
Changbin Du
prev parent reply other threads:[~2018-11-05 14:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-03 15:39 [PATCH] btrfs: avoid link error with CONFIG_NO_AUTO_INLINE Arnd Bergmann
2018-11-03 20:41 ` Nikolay Borisov
2018-11-03 21:25 ` Arnd Bergmann
2018-11-04 0:38 ` Qu Wenruo
2018-11-04 22:32 ` Arnd Bergmann
2018-11-05 16:51 ` David Sterba
2018-11-05 21:27 ` Arnd Bergmann
2018-11-06 15:04 ` David Sterba
2018-11-05 9:20 ` Nikolay Borisov
2018-11-05 14:37 ` Changbin Du [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181105143717.xrarjgcdgaipmsqd@mail.google.com \
--to=changbin.du@gmail.com \
--cc=anand.jain@oracle.com \
--cc=arnd@arndb.de \
--cc=clm@fb.com \
--cc=dsterba@suse.com \
--cc=gujx@cn.fujitsu.com \
--cc=josef@toxicpanda.com \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=misono.tomohiro@jp.fujitsu.com \
--cc=nborisov@suse.com \
--cc=wqu@suse.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).