Re: 4k stacks in 2.6

From: Brian Gerst (bgerst_at_didntduck.org)
Date: 05/27/04

  • Next message: Kumar, Sharath: "dev.c -- dev_queue_xmit-- Is the comment misleading or is it a bug??" 
    Date:	Thu, 27 May 2004 10:18:40 -0400
To: Andrea Arcangeli <andrea@suse.de>

    Andrea Arcangeli wrote:

    > On Thu, May 27, 2004 at 02:45:51PM +0200, Ingo Molnar wrote:
    >
    >>are a bit belated. I only reacted to Andrea's mail to clear up apparent
    >>misunderstandings about the impact and implementation of this feature.
    >
    >
    > note that there is something relevant to improve in the implementation,
    > that is the per-cpu irq stack size should be bigger than 4k, we use 16k
    > on x86-64, on x86 it should be 8k. Currently you're decreasing _both_
    > the normal kernel context and even the irq stack in some condition.
    > There's no good reason to decrease the irq stack too, that's cheap, it's
    > per-cpu.

    The problem on i386 (unlike x86-64) is that the thread_info struct sits
    at the bottom of the stack and is referenced by masking bits off %esp.
    So the stack size must be constant whether in process context or IRQ
    context. 

    --
				Brian Gerst
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  • Next message: Kumar, Sharath: "dev.c -- dev_queue_xmit-- Is the comment misleading or is it a bug??"

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