Re: Removing kernel thread stack swapping

From: David Xu (davidxu_at_freebsd.org)
Date: 03/03/05

  • Next message: Scott Long: "Re: Removing kernel thread stack swapping" 
    Date: Thu, 03 Mar 2005 22:37:19 +0800
To: Ryan Sommers <ryans@gamersimpact.com>

    Ryan Sommers wrote:

    > David Schultz wrote:
    >
    >> Any objections to the idea of removing the feature of swapping out
    >> kernel stacks? Unlike disabling UAREA swapping, this has the
    >> small downside that it wastes 16K (give or take a power of 2) of
    >> wired memory per kernel thread that we would otherwise have
    >> swapped out. However, this disadvantage is probably negligible by
    >> today's standards, and there are several advantages:
    >
    >
    > I like the idea of fixing a lot of possible panics. However, I don't
    > know if we should nix it completely. Wasting this little memory won't
    > hurt anyone on a contemporary computer. However, our embedded systems
    > folks don't look at memory in the same light, and 16K here or there
    > can begin to really add up in a memory tight architecture. Of course
    > it could be argued that embedded systems probably don't have many
    > threads, many threads that can be swapped, or even swap space in the
    > first place.
    >
    > I guess it's a judgment call that one of our embedded systems
    > engineers could better answer.
    >
    Does your embedded system has swap device ? I have joined some embedded
    projects in the company, and there is no swap devices at all, no HDD
    etcs, just a CF card or flash memory card and swap is totally turned off.

    David Xu

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  • Next message: Scott Long: "Re: Removing kernel thread stack swapping"

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