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From: "Martin J. Bligh" <mbligh@aracnet.com>
To: Bill Davidsen <davidsen@tmr.com>, Andrew Theurer <habanero@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org, ricklind@us.ibm.com
Subject: Re: [patch] HT scheduler, sched-2.5.68-B2
Date: Thu, 24 Apr 2003 15:39:08 -0700	[thread overview]
Message-ID: <1667780000.1051223948@flay> (raw)
In-Reply-To: <Pine.LNX.3.96.1030424162544.11351D-100000@gatekeeper.tmr.com>

> Sorry if I misunderstand, but if HT is present, I would think that you
> would want to start the child of a fork on the same runqueue, because the
> cache is loaded, and to run the child first because in many cases the
> child will do and exac. At that point it is probable that the exec'd
> process run on another CPU would leave the cache useful to the parent.
> 
> I fully admit that this is "seems to me" rather than measured, but
> protecting the cache is certainly a good thing in general.

We don't do balance on exec for SMP. I think we should ;-)
AFAIK, fork always stays on the same runqueue anyway.

>> The key is that we want to agressively steal when 
>> nr_active(remote) - nr_active(idle) > 1 ... not > 0.
>> This will implicitly *never* happen on non HT machines, so it seems
>> like a nice algorithm ... ?
> 
> Is it really that simple? 

Well, *I* think so (obviously) ;-)
Feel free to poke holes in the argument ...

M.


      reply	other threads:[~2003-04-24 22:38 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-04-23 16:23 [patch] HT scheduler, sched-2.5.68-B2 Ingo Molnar
2003-04-23 17:47 ` Martin J. Bligh
2003-04-23 17:53   ` Andrew Theurer
2003-04-23 18:43     ` Martin J. Bligh
2003-04-23 20:14       ` Andrew Theurer
2003-04-24  8:43         ` Rick Lindsley
2003-04-24 14:23           ` Andrew Theurer
2003-04-23 22:38       ` Martin J. Bligh
2003-04-24 21:29         ` Bill Davidsen
2003-04-24 22:39           ` Martin J. Bligh [this message]

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