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From: "H. Peter Anvin" <hpa@zytor.com>
To: Jan Beulich <JBeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
	Nick Piggin <npiggin@suse.de>,
	linux-kernel@vger.kernel.org
Subject: Re: uses of cmpxchg/xadd in spinlock.h and rwsem.h vs. CONFIG_M386
Date: Tue, 12 May 2009 08:51:12 -0700	[thread overview]
Message-ID: <4A099AF0.8020001@zytor.com> (raw)
In-Reply-To: <4A09AF8402000078000007DC@vpn.id2.novell.com>

Jan Beulich wrote:
> While looking at a completely different issue I happened to grep for uses of
> xadd, and it would appear to me that there got uses added that would make
> a M386-configured SMP kernel die on an actual i386.
> 
> Oh, for the rwsem case I see - it would use the RWSEM_GENERIC_SPINLOCK case
> when selecting M386. But I see nothing similar for the ticket spinlocks - am
> I overlooking something?

It's quite possible we break 386 on a regular basis... I'm not sure how
many people even in the embedded industry run current kernels on
386-compatible hardware.  Most embedded hardware is at least 486.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.


  parent reply	other threads:[~2009-05-12 15:51 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-12 15:19 uses of cmpxchg/xadd in spinlock.h and rwsem.h vs. CONFIG_M386 Jan Beulich
2009-05-12 15:37 ` Nick Piggin
2009-05-12 15:57   ` Alan Cox
2009-05-12 16:02   ` Peter Zijlstra
2009-05-12 15:51 ` H. Peter Anvin [this message]
2009-05-12 15:57   ` Nick Piggin
2009-05-12 16:04     ` H. Peter Anvin
2009-05-12 16:16       ` Jan Beulich
2009-05-12 16:18 ` Andreas Schwab

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