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From: Robert Love <rml@tech9.net>
To: Pavel Machek <pavel@ucw.cz>
Cc: Wessel Dankers <wsl@fruit.eu.org>, linux-kernel@vger.kernel.org
Subject: Re: Scheduler priorities
Date: 29 Mar 2002 18:52:21 -0500	[thread overview]
Message-ID: <1017445941.2940.78.camel@phantasy> (raw)
In-Reply-To: <20020329214252.GA9974@elf.ucw.cz>

On Fri, 2002-03-29 at 16:42, Pavel Machek wrote:

> On each entry of kernel, promote SCHED_IDLE task to SCHED_NORMAL, and
> demote it at exit. This can be done with 0 overhad on hot paths.

Agreed.

> What's the problem with "promote at enter" approach? Using ptrace
> trick, it can be 0 overhead. [Was that your code that cleverly used
> ptrace?] What is problem with it?

There is no problem with the ptrace approach, it is good - I have
experimented with that solution myself.  There is just a lot more to
SCHED_IDLE than "make the task only run when nothing else wants to" and
even the ptrace solution may involve a bit of work.

	Robert Love


      reply	other threads:[~2002-03-29 23:52 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-03-26 11:41 Scheduler priorities Nuno Miguel Rodrigues
2002-03-26 17:55 ` Mike Fedyk
2002-03-27  9:41   ` Frank Schaefer
2002-03-27 13:06     ` Nuno Miguel Rodrigues
2002-03-27 13:41       ` Robert Love
2002-03-27 20:23         ` Wessel Dankers
2002-03-27 21:14           ` Robert Love
2002-03-28  7:08             ` Wessel Dankers
2002-03-28  7:29               ` Robert Love
2002-03-29 21:42                 ` Pavel Machek
2002-03-29 23:52                   ` Robert Love [this message]

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