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From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>, Len Brown <lenb@kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86: Voluntary leave_mm before entering ACPI C3
Date: Wed, 19 Dec 2007 11:36:00 -0800	[thread overview]
Message-ID: <476972A0.3050105@zytor.com> (raw)
In-Reply-To: <20071219193255.GA2158@elte.hu>

Ingo Molnar wrote:
> * Venki Pallipadi <venkatesh.pallipadi@intel.com> wrote:
> 
>> Aviod TLB flush IPIs during C3 states by voluntary leave_mm() before 
>> entering C3.
>>
>> The performance impact of TLB flush on C3 should not be significant 
>> with respect to C3 wakeup latency. Also, CPUs tend to flush TLB in 
>> hardware while in C3 anyways.
>>

Are there any CPUs around which *don't* flush the TLB across C3?  (I 
guess it's not guaranteed by the spec, though, and as TLBs grow larger 
there might be incentive to keep them online.)

	-hpa

  reply	other threads:[~2007-12-19 19:36 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-19 18:34 Venki Pallipadi
2007-12-19 19:32 ` Ingo Molnar
2007-12-19 19:36   ` H. Peter Anvin [this message]
2007-12-19 19:40     ` Ingo Molnar
2007-12-19 19:48       ` H. Peter Anvin
2007-12-19 20:23         ` Venki Pallipadi
2007-12-20  7:53         ` Arjan van de Ven
2007-12-20 16:16           ` H. Peter Anvin
2007-12-20 18:22             ` Arjan van de Ven
2007-12-20 18:32               ` H. Peter Anvin
2007-12-20 19:28             ` Len Brown
2007-12-19 19:56       ` Venki Pallipadi
2007-12-19 20:54   ` Ingo Molnar
2007-12-20  2:08   ` Venki Pallipadi
2007-12-20  9:31     ` Ingo Molnar

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