Date: Fri, 15 Apr 2005 08:55:24 -0700 (PDT)
From: Vadim Lobanov <vlobanov@speakeasy.net>
To: Catalin Marinas <catalin.marinas@arm.com>
cc: linux-kernel@vger.kernel.org
Subject: Re: Further copy_from_user() discussion.
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On Fri, 15 Apr 2005, Catalin Marinas wrote:

> Vadim Lobanov <vlobanov@speakeasy.net> wrote:
> > I think I misspoke a bit in my email above. The intent was not to
> > eliminate all might_sleep() calls from the copy_from_user() code path;
> > but rather juggle the source around a bit so there is only one
> > might_sleep() call per each code path. Currently, in the default case,
> > it calls it twice.
> >
> > By the way, is the following still true about might_sleep()?
> > http://kerneltrap.org/node/3440/10103
>
> With Ingo's realtime-preempt patch, might_sleep() expands to
> might_resched(). The latter expands to cond_resched() only if
> CONFIG_PREEMPT_VOLUNTARY is enabled (for CONFIG_PREEMPT_RT this is not
> needed since the kernel is involuntarily preemptible). In this case it
> might be useful to have might_sleep() only called before memset().
>
> --
> Catalin
>

I agree that might_sleep() needs to be placed in the code judiciously...
just probably not so close together as it is now. :-) I can work this
out in a patch, _if_ people want me to roll a patch in the first place.

-Vadim Lobanov
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