linux-kernel - Re: [PATCH] use unfair spinlock when running on hypervisor.

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Message-ID: <87sk56ycka.fsf@basil.nowhere.org>
Date:	Tue, 01 Jun 2010 17:53:09 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Gleb Natapov <gleb@...hat.com>
Cc:	linux-kernel@...r.kernel.org, kvm@...r.kernel.org, avi@...hat.com,
	hpa@...or.com, mingo@...e.hu, npiggin@...e.de, tglx@...utronix.de,
	mtosatti@...hat.com
Subject: Re: [PATCH] use unfair spinlock when running on hypervisor.

Gleb Natapov <gleb@...hat.com> writes:
>
> The patch below allows to patch ticket spinlock code to behave similar to
> old unfair spinlock when hypervisor is detected. After patching unlocked

The question is what happens when you have a system with unfair
memory and you run the hypervisor on that. There it could be much worse.

Your new code would starve again, right?

There's a reason the ticket spinlocks were added in the first place.

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only.
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