Re: [PATCH 4.14 023/159] mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y

Greg Kroah-Hartman
2017-12-22T15:03:28Z

On Fri, Dec 22, 2017 at 08:18:10AM -0600, Dan Rue wrote:
> On Fri, Dec 22, 2017 at 09:45:08AM +0100, Greg Kroah-Hartman wrote:
> > 4.14-stable review patch. If anyone has any objections, please let me know.
> >
> > ------------------
> >
> > From: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> >
> > commit 83e3c48729d9ebb7af5a31a504f3fd6aff0348c4 upstream.
> >
> > Size of the mem_section[] array depends on the size of the physical address space.
> >
> > In preparation for boot-time switching between paging modes on x86-64
> > we need to make the allocation of mem_section[] dynamic, because otherwise
> > we waste a lot of RAM: with CONFIG_NODE_SHIFT=10, mem_section[] size is 32kB
> > for 4-level paging and 2MB for 5-level paging mode.
> >
> > The patch allocates the array on the first call to sparse_memory_present_with_active_regions().
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > Cc: Andrew Morton <akpm@linux-foundation.org>
> > Cc: Andy Lutomirski <luto@amacapital.net>
> > Cc: Borislav Petkov <bp@suse.de>
> > Cc: Cyrill Gorcunov <gorcunov@openvz.org>
> > Cc: Linus Torvalds <torvalds@linux-foundation.org>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: linux-mm@kvack.org
> > Link: http://lkml.kernel.org/r/20170929140821.37654-2-kirill.shutemov@linux.intel.com
> > Signed-off-by: Ingo Molnar <mingo@kernel.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> This patch causes a boot failure on arm64.
>
> Please drop this patch, or pick up the fix in:
>
> commit 629a359bdb0e0652a8227b4ff3125431995fec6e
> Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Date: Tue Nov 7 11:33:37 2017 +0300
>
> mm/sparsemem: Fix ARM64 boot crash when CONFIG_SPARSEMEM_EXTREME=y
>
> See https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1527427.html

Now added, thanks.

greg k-h