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SubjectRe: Strangest bug
On Fri, Jul 23, 1999 at 10:10:24PM +0200, Kurt Garloff wrote:
> On Fri, Jul 23, 1999 at 03:36:56PM -0400, Stanislav Krasilovskiy wrote:
> > This is not due to memory corruption (in the user process, I
> > continuously print out the values, and they are fine). When I use
> > mlock() on the structure, then the problem no longer occurs (the
> > copy reflects accurate values). So the problem has something to do
> > with virtual addressing and paging...
>
> You are very close to an explanation with your observation that no
> porblems occur with mlock(). mlock() does prevent paging out of the
> memory. When the page is paged out and you want to write to it in
> interrupt context, it won't work: You are not able to page it in.
> mlock() is the right solution to prevent it.

Only if the process owning the variable is running at the time of the
interrupt request and the process really undoubtedly did mlock it. In
other words, no.

--
Andreas E. Bombe <andreas.bombe@munich.netsurf.de>
http://home.pages.de/~andreas.bombe/
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