From: Andrew Morton <akpm@linux-foundation.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Christoph Lameter <cl@linux-foundation.org>,
Matthew Wilcox <matthew@wil.cx>, Yinghai Lu <yinghai@kernel.org>,
Rabin Vincent <rabin@rab.in>, lkml <linux-kernel@vger.kernel.org>,
penberg@cs.helsinki.fi, linux-arch@vger.kernel.org
Subject: Re: start_kernel(): bug: interrupts were enabled early
Date: Wed, 31 Mar 2010 23:33:30 -0400 [thread overview]
Message-ID: <20100331233330.1a7357e4.akpm@linux-foundation.org> (raw)
In-Reply-To: <4BB43CAC.3080102@zytor.com>
On Wed, 31 Mar 2010 23:26:52 -0700 "H. Peter Anvin" <hpa@zytor.com> wrote:
> On 03/31/2010 03:26 PM, Andrew Morton wrote:
> >
> > Not by adding overhead to every single down_read()/down_write() just to
> > fix a once-off startup problem - that's taking laziness way too far.
> >
>
> How much overhead is this on non-x86 architectures (keep in mind x86
> doesn't use this?)
>
Just a few instructions, I guess. But we can do it with zero.
And from a design POV, pretending that down_read()/down_write() can be
called with interrupts disabled is daft - they cannot! Why muck up the
usual code paths with this startup-specific hack?
next prev parent reply other threads:[~2010-04-01 6:35 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-25 19:41 start_kernel(): bug: interrupts were enabled early Rabin Vincent
2010-03-31 20:40 ` Andrew Morton
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
2010-03-31 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 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 [this message]
2010-04-01 6:48 ` Benjamin Herrenschmidt
2010-04-01 16:15 ` H. Peter Anvin
2010-04-01 11:06 ` David Howells
2010-04-01 15:55 ` Christoph Lameter
2010-04-01 23:00 ` Benjamin Herrenschmidt
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 21:08 ` H. Peter Anvin
2010-03-31 22:31 ` Benjamin Herrenschmidt
2010-03-31 22:36 ` H. Peter Anvin
2010-03-31 22:58 ` David Howells
2010-04-01 9:41 ` Jamie Lokier
2010-04-01 11:23 ` Matthew Wilcox
2010-04-01 10:50 ` David Howells
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