Re: [PATCH] mm/memblock: add missing include <linux/bootmem.h> and #ifdef

From: Michal Hocko
Date: Mon Jun 25 2018 - 10:03:55 EST


On Fri 22-06-18 23:05:41, Mathieu Malaterre wrote:
> Commit 26f09e9b3a06 ("mm/memblock: add memblock memory allocation apis")
> introduced two new function definitions:
>
> memblock_virt_alloc_try_nid_nopanic()
> memblock_virt_alloc_try_nid()
>
> Commit ea1f5f3712af ("mm: define memblock_virt_alloc_try_nid_raw")
> introduced the following function definition:
>
> memblock_virt_alloc_try_nid_raw()
>
> This commit adds an include of header file <linux/bootmem.h> to provide
> the missing function prototypes. Silence the following gcc warning
> (W=1):
>
> mm/memblock.c:1334:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_raw' [-Wmissing-prototypes]
> mm/memblock.c:1371:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_nopanic' [-Wmissing-prototypes]
> mm/memblock.c:1407:15: warning: no previous prototype for `memblock_virt_alloc_try_nid' [-Wmissing-prototypes]
>
> As seen in commit 6cc22dc08a24 ("revert "mm/memblock: add missing include
> <linux/bootmem.h>"") #ifdef blockers were missing which lead to compilation
> failure on mips/ia64 where CONFIG_NO_BOOTMEM=n.
>
> Suggested-by: Tony Luck <tony.luck@xxxxxxxxx>
> Signed-off-by: Mathieu Malaterre <malat@xxxxxxxxxx>

I was not aware of -Wmissing-prototypes

> ---
> mm/memblock.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 4c98672bc3e2..f4b6766d7907 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -20,6 +20,7 @@
> #include <linux/kmemleak.h>
> #include <linux/seq_file.h>
> #include <linux/memblock.h>
> +#include <linux/bootmem.h>
>
> #include <asm/sections.h>
> #include <linux/io.h>
> @@ -1226,6 +1227,7 @@ phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, i
> return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
> }
>
> +#if defined(CONFIG_HAVE_MEMBLOCK) && defined(CONFIG_NO_BOOTMEM)

Why do you need CONFIG_HAVE_MEMBLOCK dependency?
mm/Makefile says
obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o

so we even do not compile this code for !HAVE_MEMBLOCK AFAICS.

> /**
> * memblock_virt_alloc_internal - allocate boot memory block
> * @size: size of memory block to be allocated in bytes
> @@ -1433,6 +1435,7 @@ void * __init memblock_virt_alloc_try_nid(
> (u64)max_addr);
> return NULL;
> }
> +#endif
>
> /**
> * __memblock_free_early - free boot memory block
> --
> 2.11.0

--
Michal Hocko
SUSE Labs