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From: Ingo Molnar <mingo@elte.hu>
To: linux-ia64@vger.kernel.org
Subject: Re: [PATCH] SN2 user-MMIO CPU migration
Date: Tue, 24 Jan 2006 09:02:35 +0000	[thread overview]
Message-ID: <20060124090235.GA673@elte.hu> (raw)
In-Reply-To: <20060118163305.Y42462@chenjesu.americas.sgi.com>


* Brent Casavant <bcasavan@sgi.com> wrote:

> I agree with him that it's not wonderful to hook into mainline 
> scheduler code to solve this, but the alternative is what I presented 
> here: check if old CPU = new CPU at each context switch-in, entirely 
> within IA64 code.

what's the problem with doing that? It's a single comparison [of two 
values we already have accessed in that function!] and a rarely taken 
branch in a single subarch of a single arch's switch_to() function. If 
this use (of migration related arch functionality) becomes more 
widespread then we can generalize it, but right now i just dont see the 
point, given that the two solutions are almost totally equivalent in 
terms of "overhead".

	Ingo

  parent reply	other threads:[~2006-01-24  9:02 UTC|newest]

Thread overview: 83+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-01-20  0:06 [PATCH] SN2 user-MMIO CPU migration Brent Casavant
2006-01-20  0:06 ` Brent Casavant
2006-01-20  2:18 ` Jesse Barnes
2006-01-20  2:18   ` Jesse Barnes
2006-01-20  6:47   ` Brent Casavant
2006-01-20  6:47     ` Brent Casavant
2006-01-20 17:36     ` Jesse Barnes
2006-01-20 17:36       ` Jesse Barnes
2006-01-20 20:01       ` Brent Casavant
2006-01-20 20:01         ` Brent Casavant
2006-01-20 13:26   ` Jack Steiner
2006-01-20 13:26     ` Jack Steiner
2006-01-20 17:31     ` Jesse Barnes
2006-01-20 17:31       ` Jesse Barnes
2006-01-20 19:00       ` Jack Steiner
2006-01-20 19:00         ` Jack Steiner
2006-01-20  8:36 ` Ingo Molnar
2006-01-20  8:36   ` Ingo Molnar
2006-01-20 16:14   ` Brent Casavant
2006-01-20 16:14     ` Brent Casavant
2006-01-24  0:33 ` Brent Casavant
2006-01-24  0:48 ` Luck, Tony
2006-01-24  1:23 ` Brent Casavant
2006-01-24  1:42 ` Keith Owens
2006-01-24  3:41 ` Grant Grundler
2006-01-24  6:30 ` Brent Casavant
2006-01-24  6:41 ` Brent Casavant
2006-01-24  7:04 ` Grant Grundler
2006-01-24  9:02 ` Ingo Molnar [this message]
2006-01-24  9:14 ` Jes Sorensen
2006-01-24 12:10 ` Robin Holt
2006-01-24 16:40 ` Grant Grundler
2006-01-24 16:52 ` Brent Casavant
2006-01-24 16:57 ` Brent Casavant
2006-01-24 17:00 ` Robin Holt
2006-01-24 17:33 ` Luck, Tony
2006-01-24 18:42 ` Grant Grundler
2006-01-24 21:12 ` Brent Casavant
2006-01-24 21:41 ` Ingo Molnar
2006-01-24 21:43 ` Chen, Kenneth W
2006-01-24 21:51 ` Luck, Tony
2006-01-24 22:04 ` Brent Casavant
2006-01-24 22:07 ` Chen, Kenneth W
2006-01-24 22:12 ` Brent Casavant
2006-01-24 22:19 ` Chen, Kenneth W
2006-01-24 22:31 ` Chen, Kenneth W
2006-01-24 22:41 ` Brent Casavant
2006-01-24 23:25 ` Chen, Kenneth W
2006-01-24 23:28 ` Brent Casavant
2006-01-24 23:36 ` Chen, Kenneth W
2006-01-24 23:54 ` Brent Casavant
2006-01-25  0:10 ` Brent Casavant
2006-01-25  0:29 ` Chen, Kenneth W
2006-01-25  6:27 ` Keith Owens
2006-01-25  9:04 ` Chen, Kenneth W
2006-01-25  9:24 ` Chen, Kenneth W
2006-01-25 17:04 ` Brent Casavant
2006-01-25 17:45 ` Brent Casavant
2006-01-25 17:48 ` Brent Casavant
2006-01-25 19:01 ` Chen, Kenneth W
2006-01-25 19:15 ` Brent Casavant
2006-01-25 19:43 ` Jack Steiner
2006-01-25 22:49 ` Brent Casavant
2006-01-25 23:09 ` Brent Casavant
2006-01-25 23:49 ` Brent Casavant
2006-01-25 23:56 ` Chen, Kenneth W
2006-01-26  1:06 ` Luck, Tony
2006-01-26  1:31 ` Prarit Bhargava
2006-01-26  2:43 ` Keith Owens
2006-01-26  4:40 ` Brent Casavant
2006-01-26 16:29 ` Brent Casavant
2006-01-26 16:41 ` Prarit Bhargava
2006-01-26 19:29 ` Brent Casavant
2006-01-26 19:54 ` Luck, Tony
2006-01-26 20:28 ` Brent Casavant
2006-01-26 21:05 ` Luck, Tony
2006-01-26 21:34 ` Prarit Bhargava
2006-01-26 22:11 ` Luck, Tony
2006-01-26 23:08 ` Luck, Tony
2006-01-26 23:21 ` Prarit Bhargava
2006-01-26 23:44 ` Prarit Bhargava
2006-01-27  0:07 ` Chen, Kenneth W
2006-01-27 14:01 ` Prarit Bhargava

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