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From: Ingo Molnar <mingo@elte.hu>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jens Axboe <jens.axboe@oracle.com>, Andi Kleen <ak@suse.de>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: x86: Is there still value in having a special tlb flush IPI vector?
Date: Tue, 29 Jul 2008 01:34:55 +0200	[thread overview]
Message-ID: <20080728233455.GA2919@elte.hu> (raw)
In-Reply-To: <488E534F.2030204@goop.org>


* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> Now that normal smp_function_call is no longer an enormous bottleneck, 
> is there still value in having a specialised IPI vector for tlb 
> flushes?  It seems like quite a lot of duplicate code.
>
> The 64-bit tlb flush multiplexes the various cpus across 8 vectors to 
> increase scalability. If this is a big issue, then the smp function 
> call code can (and should) do the same thing.  (Though looking at it 
> more closely, the way the code uses the 8 vectors is actually a less 
> general way of doing what smp_call_function is doing anyway.)

yep, and we could eliminate the reschedule IPI as well.

	Ingo

  parent reply	other threads:[~2008-07-28 23:35 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-28 23:16 x86: Is there still value in having a special tlb flush IPI vector? Jeremy Fitzhardinge
2008-07-28 23:20 ` Jeremy Fitzhardinge
2008-07-29  2:12   ` Andi Kleen
2008-07-29  6:29     ` Jeremy Fitzhardinge
2008-07-29 12:02       ` Andi Kleen
2008-07-29 14:46         ` Jeremy Fitzhardinge
2008-07-29 14:58           ` Andi Kleen
2008-07-28 23:34 ` Ingo Molnar [this message]
2008-07-29  4:30   ` Nick Piggin
2008-07-29  6:19     ` Jeremy Fitzhardinge
2008-07-29  9:47       ` Nick Piggin
2008-07-29  9:54     ` Peter Zijlstra
2008-07-29 10:00       ` Nick Piggin
2008-07-29 10:04         ` Peter Zijlstra
2008-07-29 10:17           ` Nick Piggin
2008-07-29 10:23             ` Peter Zijlstra
2008-07-29 10:45         ` Peter Zijlstra
2008-07-31 16:48           ` Ingo Molnar
2008-08-01  1:32             ` Nick Piggin
2008-07-31 17:48           ` Jeremy Fitzhardinge
2008-07-31 20:57             ` Ingo Molnar
2008-07-31 21:15               ` Peter Zijlstra

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