Re: start_kernel(): bug: interrupts were enabled early

From: Andrew Morton
Date: Thu Apr 01 2010 - 02:35:56 EST


On Wed, 31 Mar 2010 23:26:52 -0700 "H. Peter Anvin" <hpa@xxxxxxxxx> 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?

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