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From: Erich Focht <efocht@ess.nec.de>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
	linux-ia64 <linux-ia64@linuxia64.org>
Subject: Re: O(1) scheduler "complex" macros
Date: Wed, 10 Jul 2002 11:05:29 +0200	[thread overview]
Message-ID: <200207101105.29317.efocht@ess.nec.de> (raw)
In-Reply-To: <Pine.LNX.4.44.0207102049510.15332-100000@localhost.localdomain>

Hi Ingo,

thanks for the quick response!

> the best solution might be to just lock the 'next' task - this needs a new
> per-task irq-safe spinlock, to avoid deadlocks. This way whenever a task
> is in the middle of a context-switch it cannot be scheduled on another
> CPU.

We tested this and it looked good. But inserting a udelay(100) like:
	...
	prepare_arch_switch(rq, next);
	udelay(100);
	prev = context_switch(prev, next);
	...
leads to a crash after 10 minutes. Again this looks like accessing an
empty page.

Does anything speak against such a test? It is there just to show up
quickly problems which we might normally get only after hours of running.

Regards,
Erich
 

  reply	other threads:[~2002-07-10  9:03 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-07-09 17:27 Erich Focht
2002-07-10 18:31 ` Ingo Molnar
2002-07-10 19:30   ` Ingo Molnar
2002-07-10  9:05     ` Erich Focht [this message]
2002-07-11  9:31       ` Ingo Molnar
2002-07-10 12:34         ` Erich Focht
2002-07-11  9:39         ` Ingo Molnar
2002-07-12 12:39           ` Pavel Machek
2002-07-11  9:52         ` Ingo Molnar
2002-07-11  9:25           ` Erich Focht

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