RE: [PATCH 1/5] LLVMLinux: Correct size_index table before replacing the bootstrap kmem_cache_node.

From: Daniel Sanders
Date: Wed Feb 04 2015 - 16:08:47 EST


> -----Original Message-----
> From: penberg@xxxxxxxxx [mailto:penberg@xxxxxxxxx] On Behalf Of
> Pekka Enberg
> Sent: 04 February 2015 20:42
> To: Daniel Sanders
> Cc: Christoph Lameter; David Rientjes; Joonsoo Kim; Andrew Morton; linux-
> mm@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 1/5] LLVMLinux: Correct size_index table before
> replacing the bootstrap kmem_cache_node.
>
> On Wed, Feb 4, 2015 at 10:38 PM, Daniel Sanders
> <Daniel.Sanders@xxxxxxxxxx> wrote:
> > I don't believe the bug to be LLVM specific but GCC doesn't normally
> encounter the problem. I haven't been able to identify exactly what GCC is
> doing better (probably inlining) but it seems that GCC is managing to
> optimize to the point that it eliminates the problematic allocations. This
> theory is supported by the fact that GCC can be made to fail in the same way
> by changing inline, __inline, __inline__, and __always_inline in
> include/linux/compiler-gcc.h such that they don't actually inline things.
>
> OK, makes sense. Please include that explanation in the changelog and
> drop use proper "slab" prefix instead of the confusing "LLVMLinux"
> prefix in the subject line.
>
> - Pekka

Sure. I've just updated the patch with those changes.