Re: Fix memory leak in swsusp

[Pavel Machek]

Hi!

>  > >  We were avoiding the use of memcpy because it messes up the preempt count with 3DNow, and 
>  > >  potentially as other unseen side effects. The preempt could possibly simply be reset at resume time, 
>  > >  but the point remains.
>  > 
>  > eh?  memcpy just copies memory.  Maybe your meant copy_*_user()?
> 
> See arch/i386/lib/memcpy.c  The 3dnow routine does kernel_fpu_begin()/..end()
> which futzes with preempt count.  What I'm missing though is that the count
> afterwards should be the same as it was before the memcpy. Why is this
> a problem for the suspend folks?

It does not hurt here, but as someone else explained already it is a
problem when doing atomic copy of memory. (You increment, than copy
whole memory, you decrement; but you only decrement in original, not
in copy...)
									Pavel
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