Re: [GIT PULL] x86/spinlocks optional for 3.1 [LWN.net]

From:		Linus Torvalds <torvalds-AT-linux-foundation.org>
To:		"H. Peter Anvin" <hpa-AT-linux.intel.com>
Subject:		Re: [GIT PULL] x86/spinlocks optional for 3.1
Date:		Mon, 1 Aug 2011 14:04:42 -1000
Message-ID:		<CA+55aFyKFP3KzVfSEO02TjjmMDDL5agCJjKERFdmStM4k9DtQQ@mail.gmail.com>
Cc:		"H. Peter Anvin" <hpa-AT-zytor.com>, Ingo Molnar <mingo-AT-elte.hu>, Jeremy Fitzhardinge <jeremy.fitzhardinge-AT-citrix.com>, Linux Kernel Mailing List <linux-kernel-AT-vger.kernel.org>, Thomas Gleixner <tglx-AT-linutronix.de>
Archive-link:		Article, Thread

On Mon, Aug 1, 2011 at 7:53 AM, H. Peter Anvin <hpa@linux.intel.com> wrote:
>
> Sorry for this late pull; testing on this got delayed due to my and
> Ingo's scheduling and the desire to make sure that this would not
> cause a performance regression.
>
> At this time we have good confidence in it, but if you feel this is
> too late feel free to drop it and we'll do it for 3.2.

Hmm. I don't mind it per se, but I hate how this patch that is meant
to combine the inline asm versions into one C version actually creates
*more* lines, and creates *more* inline asm differences between
x86-32/64 due to the xadd.

So quite frankly, I think the patch in this form is totally
self-defeating. I'm not pulling something that is supposed to clean
things up, but just adds more ugliness in some other place.

If that xadd implementation could perhaps be shared, I wouldn't hate
it so much. As it is, I really don't see the point in pulling this.

             Linus

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