[EMAIL PROTECTED] wrote:
> > >
> > > The are some long delays (approx. 40 secs) around __alloc_pages.
> > > Finally it crashes in memset. With the attached xenomai
> > patch, which
> > > touches the reserved page once, memset works fine. Let's wait what
> > > Philippe says. I remember that the "touch" was needed for
> > RTAI shared memory as well.
> >
> > What is the difference between touching the page in kernel
> > space and in user space? Is there no risk that the kernel
> > will oops then at some point? Do we get the same result when
> > touching the heap pages in user space immediately after
> > rt_help_alloc'ing them? Roderik's demo allocates first and
> > then touches/memsets. [I have no problem with the patch, I'm
> > just trying to understand the mechanism.]
> >
>
> Presumed that touch means "use it" (=memset) I tried to allocate a block
>
> and immediatelly use it (use memset before new heap is created).
> But this causes a segmentation fault too.
> Inspired by Gilles I set /proc/sys/vm/overcommit_memory to 2, which
> worsens
> the task behaviour (it crashes every time, not just some times).
> Do you have any further suggestions ?
Maybe the task is in fact killed by the OOM killer ? It would prove that
this function is working correctly, since the killed task is the one
that allocates all the memory. Is there no trace in the logs ?
--
Gilles Chanteperdrix.
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