All of lore.kernel.org
 help / color / mirror / Atom feed
From: Valentin Schneider <valentin.schneider@arm.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	linux-kernel@vger.kernel.org,
	Dietmar Eggemann <dietmar.eggemann@arm.com>
Subject: Re: [PATCH v1] sched/topology: Make compiler happy about unused constant definitions
Date: Tue, 25 Aug 2020 10:03:12 +0100	[thread overview]
Message-ID: <jhjd03fdrn3.mognet@arm.com> (raw)
In-Reply-To: <20200825082636.GQ1891694@smile.fi.intel.com>


On 25/08/20 09:26, Andy Shevchenko wrote:
> On Mon, Aug 24, 2020 at 06:09:41PM +0100, Valentin Schneider wrote:
>> On 24/08/20 16:39, Andy Shevchenko wrote:
>> > Compilation of almost each file ends up with
>> >
>> >  In file included from .../include/linux/energy_model.h:10,
>> >                 from .../include/linux/device.h:16,
>> >                 from .../drivers/spi/spi.c:8:
>> >  .../include/linux/sched/topology.h:30:27: warning: ‘SD_DEGENERATE_GROUPS_MASK’ defined but not used [-Wunused-const-variable=]
>> >     30 | static const unsigned int SD_DEGENERATE_GROUPS_MASK =
>> >        |                           ^~~~~~~~~~~~~~~~~~~~~~~~~
>> >  ...
>> >
>> > Make compiler happy by annotating the static constants with __maybwe_unused.
>> >
>>
>> That should see some use as long as the build is for SMP. This whole region
>> is guarded by #ifdef CONFIG_SMP, so an !SMP build shouldn't trigger this.
>
> Isn't SMP is default for most of the kernel builds?
> And honestly I didn't get the purpose of this comment.
>

Sorry, that's what I get for trying to be too succinct; what I tried to say
was that SD_DEGENERATE_GROUPS_MASK should very much be used for SMP. If the
build is !SMP, it shouldn't even be defined, IOW I'm perplexed as to where
this is coming from.

>> With what config/kernel are you getting this?
>
> x86_64_defconfig from the kernel sources with some drivers added (SMP or so has
> not been touched, DEBUG_SHED was enabled once to confirm that another static
> const has same issue).

Thanks, I'll poke around this.

  reply	other threads:[~2020-08-25  9:03 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-24 15:39 [PATCH v1] sched/topology: Make compiler happy about unused constant definitions Andy Shevchenko
2020-08-24 17:09 ` Valentin Schneider
2020-08-25  8:26   ` Andy Shevchenko
2020-08-25  9:03     ` Valentin Schneider [this message]
2020-08-25 10:12       ` Valentin Schneider
2020-08-25 11:24         ` Andy Shevchenko
2020-08-25 11:26           ` Andy Shevchenko
2020-08-25 11:32             ` Andy Shevchenko
2020-08-25 12:00               ` Valentin Schneider
2020-08-25 12:38                 ` Andy Shevchenko
2020-08-25 10:23     ` David Laight
2020-08-25 11:30       ` 'Andy Shevchenko'

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=jhjd03fdrn3.mognet@arm.com \
    --to=valentin.schneider@arm.com \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=vincent.guittot@linaro.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.