Building the kernel on s390 with -Og produces the following warning:
WARNING: vmlinux.o(.text+0x28dabe): Section mismatch in reference from the function populate_section_memmap() to the function .meminit.text:__populate_section_memmap()
The function populate_section_memmap() references
the function __meminit __populate_section_memmap().
This is often because populate_section_memmap lacks a __meminit
annotation or the annotation of __populate_section_memmap is wrong.
While -Og is not supported, in theory this might still happen with
another compiler or on another architecture. So fix this by using the
correct section annotations.
Signed-off-by: Ilya Leoshkevich <[email protected]>
---
mm/sparse.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index f6891c1992b1..0f1f36443a96 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -448,7 +448,7 @@ static unsigned long __init section_map_size(void)
return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
}
-struct page __init *__populate_section_memmap(unsigned long pfn,
+struct page __meminit *__populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
unsigned long size = section_map_size();
@@ -647,7 +647,7 @@ void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
#endif
#ifdef CONFIG_SPARSEMEM_VMEMMAP
-static struct page *populate_section_memmap(unsigned long pfn,
+static struct page * __meminit populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
return __populate_section_memmap(pfn, nr_pages, nid, altmap);
@@ -669,7 +669,7 @@ static void free_map_bootmem(struct page *memmap)
vmemmap_free(start, end, NULL);
}
#else
-struct page *populate_section_memmap(unsigned long pfn,
+struct page * __meminit populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
struct page *page, *ret;
--
2.23.0
On 28.10.19 17:55, Ilya Leoshkevich wrote:
> Building the kernel on s390 with -Og produces the following warning:
>
> WARNING: vmlinux.o(.text+0x28dabe): Section mismatch in reference from the function populate_section_memmap() to the function .meminit.text:__populate_section_memmap()
> The function populate_section_memmap() references
> the function __meminit __populate_section_memmap().
> This is often because populate_section_memmap lacks a __meminit
> annotation or the annotation of __populate_section_memmap is wrong.
>
> While -Og is not supported, in theory this might still happen with
> another compiler or on another architecture. So fix this by using the
> correct section annotations.
>
> Signed-off-by: Ilya Leoshkevich <[email protected]>
> ---
> mm/sparse.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/sparse.c b/mm/sparse.c
> index f6891c1992b1..0f1f36443a96 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -448,7 +448,7 @@ static unsigned long __init section_map_size(void)
> return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
> }
>
> -struct page __init *__populate_section_memmap(unsigned long pfn,
> +struct page __meminit *__populate_section_memmap(unsigned long pfn,
> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
> {
> unsigned long size = section_map_size();
> @@ -647,7 +647,7 @@ void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
> #endif
>
> #ifdef CONFIG_SPARSEMEM_VMEMMAP
> -static struct page *populate_section_memmap(unsigned long pfn,
> +static struct page * __meminit populate_section_memmap(unsigned long pfn,
> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
> {
> return __populate_section_memmap(pfn, nr_pages, nid, altmap);
> @@ -669,7 +669,7 @@ static void free_map_bootmem(struct page *memmap)
> vmemmap_free(start, end, NULL);
> }
> #else
> -struct page *populate_section_memmap(unsigned long pfn,
> +struct page * __meminit populate_section_memmap(unsigned long pfn,
> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
> {
> struct page *page, *ret;
>
So mm/sparse-vmemmap.c:__populate_section_memmap() already has this
annotation. I guess it's the right thing to do as
populate_section_memmap() is called from
static struct page * __meminit section_activate()
Acked-by: David Hildenbrand <[email protected]>
--
Thanks,
David / dhildenb
Hi Ilya,
I love your patch! Perhaps something to improve:
[auto build test WARNING on mmotm/master]
url: https://github.com/0day-ci/linux/commits/Ilya-Leoshkevich/mm-sparse-c-mark-populate_section_memmap-as-__meminit/20191030-113800
base: git://git.cmpxchg.org/linux-mmotm.git master
config: sh-allnoconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 7.4.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
GCC_VERSION=7.4.0 make.cross ARCH=sh
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <[email protected]>
All warnings (new ones prefixed by >>):
>> WARNING: vmlinux.o(.meminit.text+0x153c): Section mismatch in reference from the function __populate_section_memmap() to the function .init.text:memblock_alloc_try_nid()
The function __meminit __populate_section_memmap() references
a function __init memblock_alloc_try_nid().
If memblock_alloc_try_nid is only used by __populate_section_memmap then
annotate memblock_alloc_try_nid with a matching annotation.
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Mon, Oct 28, 2019 at 05:55:49PM +0100, Ilya Leoshkevich wrote:
> Building the kernel on s390 with -Og produces the following warning:
>
> WARNING: vmlinux.o(.text+0x28dabe): Section mismatch in reference from the function populate_section_memmap() to the function .meminit.text:__populate_section_memmap()
> The function populate_section_memmap() references
> the function __meminit __populate_section_memmap().
> This is often because populate_section_memmap lacks a __meminit
> annotation or the annotation of __populate_section_memmap is wrong.
>
> While -Og is not supported, in theory this might still happen with
> another compiler or on another architecture. So fix this by using the
> correct section annotations.
>
> Signed-off-by: Ilya Leoshkevich <[email protected]>
> ---
> mm/sparse.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/mm/sparse.c b/mm/sparse.c
> index f6891c1992b1..0f1f36443a96 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -448,7 +448,7 @@ static unsigned long __init section_map_size(void)
> return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
> }
>
> -struct page __init *__populate_section_memmap(unsigned long pfn,
> +struct page __meminit *__populate_section_memmap(unsigned long pfn,
> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
> {
> unsigned long size = section_map_size();
> @@ -647,7 +647,7 @@ void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
> #endif
>
> #ifdef CONFIG_SPARSEMEM_VMEMMAP
> -static struct page *populate_section_memmap(unsigned long pfn,
> +static struct page * __meminit populate_section_memmap(unsigned long pfn,
> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
> {
> return __populate_section_memmap(pfn, nr_pages, nid, altmap);
> @@ -669,7 +669,7 @@ static void free_map_bootmem(struct page *memmap)
> vmemmap_free(start, end, NULL);
> }
> #else
> -struct page *populate_section_memmap(unsigned long pfn,
> +struct page * __meminit populate_section_memmap(unsigned long pfn,
> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
> {
> struct page *page, *ret;
I did not really check deep, but I __think__ you only need to add __meminit in
populate_section_memmap functions.
__populate_section_memmap for SPARSE case is only used at init phase.
--
Oscar Salvador
SUSE L3
> Am 30.10.2019 um 09:14 schrieb Oscar Salvador <[email protected]>:
>
> On Mon, Oct 28, 2019 at 05:55:49PM +0100, Ilya Leoshkevich wrote:
>> Building the kernel on s390 with -Og produces the following warning:
>>
>> WARNING: vmlinux.o(.text+0x28dabe): Section mismatch in reference from the function populate_section_memmap() to the function .meminit.text:__populate_section_memmap()
>> The function populate_section_memmap() references
>> the function __meminit __populate_section_memmap().
>> This is often because populate_section_memmap lacks a __meminit
>> annotation or the annotation of __populate_section_memmap is wrong.
>>
>> While -Og is not supported, in theory this might still happen with
>> another compiler or on another architecture. So fix this by using the
>> correct section annotations.
>>
>> Signed-off-by: Ilya Leoshkevich <[email protected]>
>> ---
>> mm/sparse.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/mm/sparse.c b/mm/sparse.c
>> index f6891c1992b1..0f1f36443a96 100644
>> --- a/mm/sparse.c
>> +++ b/mm/sparse.c
>> @@ -448,7 +448,7 @@ static unsigned long __init section_map_size(void)
>> return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
>> }
>>
>> -struct page __init *__populate_section_memmap(unsigned long pfn,
>> +struct page __meminit *__populate_section_memmap(unsigned long pfn,
>> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
>> {
>> unsigned long size = section_map_size();
>> @@ -647,7 +647,7 @@ void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
>> #endif
>>
>> #ifdef CONFIG_SPARSEMEM_VMEMMAP
>> -static struct page *populate_section_memmap(unsigned long pfn,
>> +static struct page * __meminit populate_section_memmap(unsigned long pfn,
>> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
>> {
>> return __populate_section_memmap(pfn, nr_pages, nid, altmap);
>> @@ -669,7 +669,7 @@ static void free_map_bootmem(struct page *memmap)
>> vmemmap_free(start, end, NULL);
>> }
>> #else
>> -struct page *populate_section_memmap(unsigned long pfn,
>> +struct page * __meminit populate_section_memmap(unsigned long pfn,
>> unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
>> {
>> struct page *page, *ret;
>
> I did not really check deep, but I __think__ you only need to add __meminit in
> populate_section_memmap functions.
>
> __populate_section_memmap for SPARSE case is only used at init phase.
You are absolutely right, and this is what must be causing the problem
on sh4.
With CONFIG_SPARSEMEM_VMEMMAP, populate_section_memmap calls
__populate_section_memmap version from mm/sparse-vmemmap.c, which is
already marked as __meminit.
Without CONFIG_SPARSEMEM_VMEMMAP, populate_section_memmap does not
call __populate_section_memmap (which is then defined in mm/sparse.c).
Like you said, in this case the latter is called only during the init
phase (by sparse_init_nid), so it should keep the __init annotation.
I think it still makes sense to mark the !CONFIG_SPARSEMEM_VMEMMAP
version of populate_section_memmap as __meminit, since it's only called
from __meminit section_activate.
I will send a v2.