svn commit: r326758 - in head/sys/i386: conf include

[Nathan Whitehorn]

On 12/20/17 09:14, John Baldwin wrote:
> On Wednesday, December 20, 2017 09:59:26 AM David Chisnall wrote:
>> On 16 Dec 2017, at 18:05, John Baldwin <jhb at FreeBSD.org> wrote:
>>> When I build a FreeBSD/mips64 kernel with clang,
>>> _any_ simple NFS op triggers a kernel stack overflow.  Kernels compiled
>>> with GCC do not.
>> That is not my experience.  I haven’t tried a MIPS64 kernel built with clang, but with in-tree gcc I get kernel panics as soon as I try to use NFS, unless I use Stacey’s patches that increase the kernel stack size.
> I have primarily been using modern GCC for GCC once that was working, but at
> least when running a MALTA64 kernel under qemu I was not triggering panics
> even with old GCC.  With the in-tree clang 5.0 or with CHERI clang, just
> doing an 'ls' of a NFS directory or even a tab-complete of a path that
> is on NFS reliably triggers a kernel stack overflow for MALTA64 in qemu.
>
> With Stacey's kstack pages, a clang kernel does survive, but those are not
> in stock FreeBSD which is where I have been testing this.
>

With GCC 4, it takes a little while, but trying to build ports over NFS 
is a sure-fire way to bring down the kernel. I haven't tried any other 
compilers.
-Nathan