From: Guenter Roeck <linux@roeck-us.net>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"David Laight" <David.Laight@ACULAB.COM>
Cc: Russell King <linux@arm.linux.org.uk>,
Peter Zijlstra <peterz@infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Paul Mackerras <paulus@samba.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2] sched: Fix compiler warnings
Date: Wed, 25 Jun 2014 09:09:08 -0700 [thread overview]
Message-ID: <53AAF424.6010302@roeck-us.net> (raw)
In-Reply-To: <20140625155259.GQ14781@pengutronix.de>
On 06/25/2014 08:52 AM, Uwe Kleine-König wrote:
> Hello,
>
> On Wed, Jun 25, 2014 at 03:40:28PM +0000, David Laight wrote:
>> From: Guenter Roeck
>>> Actually turns out one can use __attribute_const__, and it is
>>>
>>> static inline int __attribute_const__ cpu_corepower_flags(void)
>>>
>>> which turns out to be widely used.
>>>
>>> I'll change that and resubmit after testing.
>>
>> You don't need to tell the compiler that for an inline function.
> I didn't check for the functions in question here, but in general your
> statement is wrong.
>
> For example:
>
> static inline unsigned int __attribute_const__ read_cpuid_id(void)
> {
> return readl(BASEADDR_V7M_SCB + V7M_SCB_CPUID);
> }
>
> from arch/arm/include/asm/cputype.h. The V7M_SCB_CPUID register never
> changes, but there is no way gcc can deduce that.
>
Sigh. As I mentioned earlier, it is much easier to introduce a problem
than to fix it.
Ok, I'll leave this alone. I already spent much more time on this than
I should or have, so it is really time to move on.
Guenter
WARNING: multiple messages have this Message-ID (diff)
From: linux@roeck-us.net (Guenter Roeck)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] sched: Fix compiler warnings
Date: Wed, 25 Jun 2014 09:09:08 -0700 [thread overview]
Message-ID: <53AAF424.6010302@roeck-us.net> (raw)
In-Reply-To: <20140625155259.GQ14781@pengutronix.de>
On 06/25/2014 08:52 AM, Uwe Kleine-K?nig wrote:
> Hello,
>
> On Wed, Jun 25, 2014 at 03:40:28PM +0000, David Laight wrote:
>> From: Guenter Roeck
>>> Actually turns out one can use __attribute_const__, and it is
>>>
>>> static inline int __attribute_const__ cpu_corepower_flags(void)
>>>
>>> which turns out to be widely used.
>>>
>>> I'll change that and resubmit after testing.
>>
>> You don't need to tell the compiler that for an inline function.
> I didn't check for the functions in question here, but in general your
> statement is wrong.
>
> For example:
>
> static inline unsigned int __attribute_const__ read_cpuid_id(void)
> {
> return readl(BASEADDR_V7M_SCB + V7M_SCB_CPUID);
> }
>
> from arch/arm/include/asm/cputype.h. The V7M_SCB_CPUID register never
> changes, but there is no way gcc can deduce that.
>
Sigh. As I mentioned earlier, it is much easier to introduce a problem
than to fix it.
Ok, I'll leave this alone. I already spent much more time on this than
I should or have, so it is really time to move on.
Guenter
WARNING: multiple messages have this Message-ID (diff)
From: Guenter Roeck <linux@roeck-us.net>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"David Laight" <David.Laight@ACULAB.COM>
Cc: Russell King <linux@arm.linux.org.uk>,
Peter Zijlstra <peterz@infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ingo Molnar <mingo@redhat.com>, Paul Mackerras <paulus@samba.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
Ingo Molnar <mingo@kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2] sched: Fix compiler warnings
Date: Wed, 25 Jun 2014 09:09:08 -0700 [thread overview]
Message-ID: <53AAF424.6010302@roeck-us.net> (raw)
In-Reply-To: <20140625155259.GQ14781@pengutronix.de>
On 06/25/2014 08:52 AM, Uwe Kleine-König wrote:
> Hello,
>
> On Wed, Jun 25, 2014 at 03:40:28PM +0000, David Laight wrote:
>> From: Guenter Roeck
>>> Actually turns out one can use __attribute_const__, and it is
>>>
>>> static inline int __attribute_const__ cpu_corepower_flags(void)
>>>
>>> which turns out to be widely used.
>>>
>>> I'll change that and resubmit after testing.
>>
>> You don't need to tell the compiler that for an inline function.
> I didn't check for the functions in question here, but in general your
> statement is wrong.
>
> For example:
>
> static inline unsigned int __attribute_const__ read_cpuid_id(void)
> {
> return readl(BASEADDR_V7M_SCB + V7M_SCB_CPUID);
> }
>
> from arch/arm/include/asm/cputype.h. The V7M_SCB_CPUID register never
> changes, but there is no way gcc can deduce that.
>
Sigh. As I mentioned earlier, it is much easier to introduce a problem
than to fix it.
Ok, I'll leave this alone. I already spent much more time on this than
I should or have, so it is really time to move on.
Guenter
next prev parent reply other threads:[~2014-06-25 16:09 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-25 1:05 [PATCH v2] sched: Fix compiler warnings Guenter Roeck
2014-06-25 1:05 ` Guenter Roeck
2014-06-25 1:05 ` Guenter Roeck
2014-06-25 1:23 ` Benjamin Herrenschmidt
2014-06-25 1:23 ` Benjamin Herrenschmidt
2014-06-25 1:23 ` Benjamin Herrenschmidt
2014-06-25 6:41 ` Vincent Guittot
2014-06-25 6:41 ` Vincent Guittot
2014-06-25 6:41 ` Vincent Guittot
2014-06-25 7:14 ` Uwe Kleine-König
2014-06-25 7:14 ` Uwe Kleine-König
2014-06-25 7:14 ` Uwe Kleine-König
2014-06-25 14:27 ` Guenter Roeck
2014-06-25 14:27 ` Guenter Roeck
2014-06-25 14:27 ` Guenter Roeck
2014-06-25 14:49 ` Uwe Kleine-König
2014-06-25 14:49 ` Uwe Kleine-König
2014-06-25 14:49 ` Uwe Kleine-König
2014-06-25 15:03 ` Guenter Roeck
2014-06-25 15:03 ` Guenter Roeck
2014-06-25 15:03 ` Guenter Roeck
2014-06-25 15:40 ` David Laight
2014-06-25 15:40 ` David Laight
2014-06-25 15:40 ` David Laight
2014-06-25 15:52 ` Uwe Kleine-König
2014-06-25 15:52 ` Uwe Kleine-König
2014-06-25 15:52 ` Uwe Kleine-König
2014-06-25 16:04 ` David Laight
2014-06-25 16:04 ` David Laight
2014-06-25 16:04 ` David Laight
2014-06-25 16:09 ` Guenter Roeck [this message]
2014-06-25 16:09 ` Guenter Roeck
2014-06-25 16:09 ` Guenter Roeck
2014-06-26 0:59 ` Stephen Rothwell
2014-06-26 0:59 ` Stephen Rothwell
2014-06-26 0:59 ` Stephen Rothwell
2014-06-26 3:27 ` Guenter Roeck
2014-06-26 3:27 ` Guenter Roeck
2014-06-26 3:27 ` Guenter Roeck
2014-07-02 6:37 ` [tip:sched/urgent] " tip-bot for Guenter Roeck
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