Re: [PATCH v2 00/15] Avoid MAP_FIXED gap exposure

["Liam R. Howlett" <Liam.Howlett@oracle.com>]

* Bert Karwatzki <spasswolf@web.de> [240703 10:30]:
> 
> > Thanks.  Is this the first error printed in the kern.log?
> 
> Yes. Uptime was about an hour when it occurred.
> 
> > It could very likely be me, but I don't know how the count would have
> > errors so late in the process life cycle - do you have
> > CONFIG_DEBUG_VM_MAPLE_TREE enabled?  This would check the count against
> > the tree on modifications and would narrow down where things could have
> > gone wrong.
> 
> Unfortunately, the panicking kernel was compiled without CONFIG_DEBUG_VM_MAPLE_TREE.
> After the error I recompiled it with that option enabled. This kernel is running for
> about 3 hours without the error reappearing.
> 

I sent v3 after producing an error with stress-ng --vm-sigv, which
unmaps the entire process space.  That might be at play with what you
saw, but I'm still unsure if your issue is fixed by this change.  I was
unable to reproduce the issue you saw against the mm-unstable and
mm-stable branch, but that might just mean it's rare.

Thanks,
Liam