From: "H. Peter Anvin" <hpa@zytor.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Yinghai Lu <yinghai@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Rabin Vincent <rabin@rab.in>, lkml <linux-kernel@vger.kernel.org>,
penberg@cs.helsinki.fi, cl@linux-foundation.org,
linux-arch@vger.kernel.org
Subject: Re: start_kernel(): bug: interrupts were enabled early
Date: Wed, 31 Mar 2010 15:36:26 -0700 [thread overview]
Message-ID: <4BB3CE6A.2080406@zytor.com> (raw)
In-Reply-To: <1270074687.7101.74.camel@pasglop>
On 03/31/2010 03:31 PM, Benjamin Herrenschmidt wrote:
> On Wed, 2010-03-31 at 13:47 -0700, Yinghai Lu wrote:
>>> perhaps the second one isn't needed? Perhaps no architecture
>> requires
>>> that local interrupts be disabled across the above initialisations?
>>
>> spin_unlock_irq from arm is different from other archs?
>
> No, it's not, it will enable IRQs and thats illegal to do so early
> during boot. We've been over that one again and again, the problem is
> that people want to keep using that instead of irqsave/restore because
> it's a nano-optimisation on x86... oh well...
>
Well, guess what... the particular user in this case *isn't used at all
on x86* so it is a non-issue here. So I take it we have your particular
vote to use irqsave/irqrestore in lib/rwsem-spinlock.c?
-hpa
prev parent reply other threads:[~2010-03-31 22:40 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20100325194100.GA2364@debian>
2010-03-31 20:40 ` start_kernel(): bug: interrupts were enabled early Andrew Morton
2010-03-31 20:47 ` Yinghai Lu
2010-03-31 20:47 ` Yinghai Lu
2010-03-31 20:52 ` Andrew Morton
2010-03-31 21:12 ` H. Peter Anvin
2010-03-31 21:28 ` Andrew Morton
2010-03-31 22:35 ` Benjamin Herrenschmidt
2010-04-01 16:13 ` Linus Torvalds
2010-04-01 14:27 ` Andrew Morton
2010-04-01 20:12 ` Linus Torvalds
2010-04-02 14:46 ` David Howells
2010-04-02 14:54 ` Linus Torvalds
2010-04-07 19:09 ` Kevin Hilman
2010-04-08 15:55 ` Américo Wang
2010-04-08 15:55 ` Américo Wang
2010-03-31 21:01 ` Matthew Wilcox
2010-03-31 21:05 ` H. Peter Anvin
2010-03-31 21:17 ` Matthew Wilcox
2010-03-31 21:42 ` Christoph Lameter
2010-03-31 21:54 ` Russell King
2010-03-31 21:57 ` H. Peter Anvin
2010-03-31 21:57 ` H. Peter Anvin
2010-03-31 22:30 ` Russell King
2010-03-31 22:37 ` Benjamin Herrenschmidt
2010-03-31 22:49 ` Andrew Morton
2010-04-01 1:17 ` Benjamin Herrenschmidt
2010-03-31 22:26 ` Andrew Morton
2010-04-01 6:26 ` H. Peter Anvin
2010-04-01 3:33 ` Andrew Morton
2010-04-01 6:48 ` Benjamin Herrenschmidt
2010-04-01 11:06 ` David Howells
2010-04-01 15:55 ` Christoph Lameter
2010-04-01 23:00 ` Benjamin Herrenschmidt
2010-04-01 16:15 ` H. Peter Anvin
2010-04-01 16:15 ` H. Peter Anvin
2010-04-01 6:50 ` Benjamin Herrenschmidt
2010-03-31 22:36 ` Benjamin Herrenschmidt
2010-04-01 15:57 ` Christoph Lameter
2010-03-31 21:05 ` Russell King
2010-03-31 21:05 ` Russell King
2010-03-31 21:08 ` H. Peter Anvin
2010-03-31 21:08 ` H. Peter Anvin
2010-03-31 22:58 ` David Howells
2010-04-01 9:41 ` Jamie Lokier
2010-04-01 10:50 ` David Howells
2010-04-01 11:23 ` Matthew Wilcox
2010-03-31 22:31 ` Benjamin Herrenschmidt
2010-03-31 22:36 ` H. Peter Anvin [this message]
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