From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Will Deacon <will.deacon@arm.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
"H. Peter Anvin" <hpa@zytor.com>,
"linux-next@vger.kernel.org" <linux-next@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Paul McKenney <paulmck@linux.vnet.ibm.com>
Subject: Re: linux-next: build warnings after merge of the access_once tree
Date: Thu, 26 Mar 2015 19:54:20 +0100 [thread overview]
Message-ID: <551455DC.4080604@de.ibm.com> (raw)
In-Reply-To: <CA+55aFw6f4sLc4DMTmd2T9-r8NNQq8Zr4Wf1SvHSG=s1Vd-WuA@mail.gmail.com>
Am 26.03.2015 um 18:52 schrieb Linus Torvalds:
> On Thu, Mar 26, 2015 at 10:24 AM, Christian Borntraeger
> <borntraeger@de.ibm.com> wrote:
>>
>> Oh I just added that check back then because some guy named
>> Linus suggested something like that ;-)
>
> Yes, my bad.
>
> In my defense, that was when we were talking about ACCESS_ONCE()
> causing bugs with gcc due to the blind use of "volatile" that it turns
> out gcc doesn't necessarily like.
>
> With the memcpy fallback (and the simpler "scalar pointer copy by
> hand"), I think READ_ONCE() (and WRITE_ONCE()) are safe.
>
> Linus
>
FWIW, I dropped the warning fixp patch from my linux-next branch so
everything should be back to normal and we can merge Peters patch for 4.0 or
4.1.
Christian
prev parent reply other threads:[~2015-03-26 18:54 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-26 8:31 linux-next: build warnings after merge of the access_once tree Stephen Rothwell
2015-03-26 10:11 ` Christian Borntraeger
2015-03-26 10:34 ` Peter Zijlstra
2015-03-26 13:27 ` Will Deacon
2015-03-26 14:22 ` Peter Zijlstra
2015-03-26 14:41 ` Will Deacon
2015-03-26 14:51 ` Peter Zijlstra
2015-03-26 15:08 ` Will Deacon
2015-03-26 16:15 ` Linus Torvalds
2015-03-26 16:21 ` Linus Torvalds
2015-03-26 16:36 ` Peter Zijlstra
2015-03-26 16:44 ` Peter Zijlstra
2015-03-26 16:45 ` Peter Zijlstra
[not found] ` <CA+55aFw1WHJqSj+z-mJGY-kxrg_OsGp9jK9VBi+wB4zPgCkv_w@mail.gmail.com>
2015-03-26 17:07 ` Peter Zijlstra
2015-03-26 17:17 ` Will Deacon
2015-03-26 17:23 ` Christian Borntraeger
2015-03-26 19:42 ` Christian Borntraeger
2015-03-26 16:28 ` Peter Zijlstra
[not found] ` <CA+55aFzUPPSHakwbp-Y-SaXB+o1=V6rOknz7L3AYNXNPU1MSfg@mail.gmail.com>
2015-03-26 17:12 ` Paul E. McKenney
2015-03-26 17:24 ` Christian Borntraeger
2015-03-26 17:52 ` Linus Torvalds
2015-03-26 18:54 ` Christian Borntraeger [this message]
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