From: David Mosberger <davidm@hpl.hp.com>
To: linux-ia64@vger.kernel.org
Subject: Re: [Linux-ia64] Help with Ingo scheduler on IA64
Date: Mon, 21 Jan 2002 20:23:08 +0000 [thread overview]
Message-ID: <marc-linux-ia64-105590698805906@msgid-missing> (raw)
In-Reply-To: <marc-linux-ia64-105590698805816@msgid-missing>
>>>>> On Mon, 21 Jan 2002 23:11:49 +0100 (CET), Ingo Molnar <mingo@elte.hu> said:
Ingo> On Mon, 21 Jan 2002, David Mosberger wrote:
Ingo> we call context_switch() with irqs disabled. The ia64 version
Ingo> of switch_to() should not re-enable IRQs or it will deadlock.
>> The existing switch_to() enables interrupts if the new task's
>> stack is on a different (kernel-) page.
Ingo> oh, i see. Why were irqs enabled explicitly? The old scheduler
Ingo> called switch_to() with irqs enabled, all the time.
Eh, that's not true. The old scheduler did spin_unlock_irq() before
calling switch_to(). If your scheduler requires irq's to be disabled
during context switch, it's going to have bigger interrupt response
latency. That's a disadvantage.
--david
next prev parent reply other threads:[~2002-01-21 20:23 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-01-12 2:23 [Linux-ia64] Help with Ingo scheduler on IA64 Nick Pollitt
2002-01-12 3:13 ` David Mosberger
2002-01-14 18:23 ` Erich Focht
2002-01-15 1:07 ` Nick Pollitt
2002-01-15 9:28 ` Erich Focht
2002-01-15 17:53 ` Erich Focht
2002-01-15 17:58 ` Erich Focht
2002-01-15 18:59 ` Erich Focht
2002-01-15 19:52 ` Ingo Molnar
2002-01-15 19:57 ` Ingo Molnar
2002-01-15 20:12 ` Ingo Molnar
2002-01-16 5:30 ` Nick Pollitt
2002-01-16 21:04 ` Erich Focht
2002-01-17 1:42 ` David Mosberger
2002-01-17 5:39 ` Nick Pollitt
2002-01-17 8:06 ` David Mosberger
2002-01-17 9:43 ` Ingo Molnar
2002-01-17 9:45 ` Ingo Molnar
2002-01-17 18:25 ` Erich Focht
2002-01-17 21:17 ` Ingo Molnar
2002-01-19 17:17 ` Erich Focht
2002-01-19 20:10 ` David Mosberger
2002-01-21 16:23 ` Erich Focht
2002-01-21 18:24 ` Erich Focht
2002-01-21 18:45 ` Erich Focht
2002-01-21 20:10 ` David Mosberger
2002-01-21 20:23 ` David Mosberger [this message]
2002-01-21 20:32 ` Ingo Molnar
2002-01-21 20:41 ` David Mosberger
2002-01-21 21:11 ` Ingo Molnar
2002-01-21 22:11 ` Ingo Molnar
2002-01-21 22:27 ` Ingo Molnar
2002-01-21 22:30 ` Ingo Molnar
2002-01-21 22:41 ` Ingo Molnar
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