Re: [PATCH] ia64: fix build failure caused by memory model changes

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Dec 18, 2020 at 06:35:50PM +0200, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
> 
> The change of ia64's default memory model to SPARSEMEM causes defconfig
> build to fail:
> 
>   CC      kernel/async.o
> In file included from include/linux/numa.h:25,
>                  from include/linux/async.h:13,
>                  from kernel/async.c:47:
> arch/ia64/include/asm/sparsemem.h:14:40: warning: "PAGE_SHIFT" is not defined, evaluates to 0 [-Wundef]
>    14 | #if ((CONFIG_FORCE_MAX_ZONEORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS)
>       |                                        ^~~~~~~~~~
> In file included from include/linux/gfp.h:6,
>                  from include/linux/xarray.h:14,
>                  from include/linux/radix-tree.h:19,
>                  from include/linux/idr.h:15,
>                  from include/linux/kernfs.h:13,
>                  from include/linux/sysfs.h:16,
>                  from include/linux/kobject.h:20,
>                  from include/linux/energy_model.h:7,
>                  from include/linux/device.h:16,
>                  from include/linux/async.h:14,
>                  from kernel/async.c:47:
> include/linux/mmzone.h:1156:2: error: #error Allocator MAX_ORDER exceeds SECTION_SIZE
>  1156 | #error Allocator MAX_ORDER exceeds SECTION_SIZE
>       |  ^~~~~
> 
> The error cause is the missing definition of PAGE_SHIFT in the calculation
> of SECTION_SIZE_BITS.
> 
> Add include of <asm/page.h> to arch/ia64/include/asm/sparsemem.h to solve
> the problem.
> 
> Fixes: 214496cb1870 ("ia64: make SPARSEMEM default and disable DISCONTIGMEM")
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>

Tested-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
> Surprisingly, only Guenter's bot caught this.
> 
> @Andrew, if you prefer I can take this via memblock tree.
> 
>  arch/ia64/include/asm/sparsemem.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/ia64/include/asm/sparsemem.h b/arch/ia64/include/asm/sparsemem.h
> index dd8c166ffd7b..42ed5248fae9 100644
> --- a/arch/ia64/include/asm/sparsemem.h
> +++ b/arch/ia64/include/asm/sparsemem.h
> @@ -3,6 +3,7 @@
>  #define _ASM_IA64_SPARSEMEM_H
>  
>  #ifdef CONFIG_SPARSEMEM
> +#include <asm/page.h>
>  /*
>   * SECTION_SIZE_BITS            2^N: how big each section will be
>   * MAX_PHYSMEM_BITS             2^N: how much memory we can have in that space
> -- 
> 2.28.0
>