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

[Greg Kroah-Hartman]

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@xxxxxxxxxxxxxxx>
> > 
> > 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@xxxxxxxxxxxxxxx>
> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
> > Cc: Borislav Petkov <bp@xxxxxxx>
> > Cc: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: linux-mm@xxxxxxxxx
> > Link: http://lkml.kernel.org/r/20170929140821.37654-2-kirill.shutemov@xxxxxxxxxxxxxxx
> > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> 
> 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@xxxxxxxxxxxxxxx>
>     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@xxxxxxxxxxxxxxx/msg1527427.html

Now added, thanks.

greg k-h