lkml.org 
[lkml]   [2004]   [Jun]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Fix memory leak in swsusp
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
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:03    [W:0.222 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site