2021-10-11 11:30:10

by Faiyaz Mohammed

[permalink] [raw]
Subject: [PATCH v2] mm: page_alloc: Add debug log in free_reserved_area for static memory

From: Faiyaz Mohammed <[email protected]>

For INITRD and initmem memory is reserved through "memblock_reserve"
during boot up but it is free via "free_reserved_area" instead
of "memblock_free".
For example:
[ 0.294848] Freeing initrd memory: 12K.
[ 0.696688] Freeing unused kernel memory: 4096K.

To get the start and end address of the above freed memory and to account
proper memblock added pr_debug log in "free_reserved_area".
After adding log:
[ 0.294837] 0x00000083600000-0x00000083603000 free_initrd_mem+0x20/0x28
[ 0.294848] Freeing initrd memory: 12K.
[ 0.695246] 0x00000081600000-0x00000081a00000 free_initmem+0x70/0xc8
[ 0.696688] Freeing unused kernel memory: 4096K.

Signed-off-by: Faiyaz Mohammed <[email protected]>
---
changes in v2:
- To avoid confusion, remove the memblock_dbg print and drop the
memblock_free string, now using pr_debug to print the address ranges.

mm/page_alloc.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 668edb1..395df3f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8153,6 +8153,11 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char
if (pages && s)
pr_info("Freeing %s memory: %ldK\n", s, K(pages));

+#ifdef CONFIG_HAVE_MEMBLOCK
+ pr_debug("%#016llx-%#016llx %pS\n",
+ __pa(start), __pa(end), (void *)_RET_IP_);
+#endif
+
return pages;
}

--
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member of the Code Aurora Forum, hosted by The Linux Foundation


2021-10-11 12:13:14

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH v2] mm: page_alloc: Add debug log in free_reserved_area for static memory

On 11.10.21 09:11, Faiyaz Mohammed wrote:
> From: Faiyaz Mohammed <[email protected]>
>
> For INITRD and initmem memory is reserved through "memblock_reserve"
> during boot up but it is free via "free_reserved_area" instead
> of "memblock_free".
> For example:
> [ 0.294848] Freeing initrd memory: 12K.
> [ 0.696688] Freeing unused kernel memory: 4096K.
>
> To get the start and end address of the above freed memory and to account
> proper memblock added pr_debug log in "free_reserved_area".
> After adding log:
> [ 0.294837] 0x00000083600000-0x00000083603000 free_initrd_mem+0x20/0x28
> [ 0.294848] Freeing initrd memory: 12K.
> [ 0.695246] 0x00000081600000-0x00000081a00000 free_initmem+0x70/0xc8
> [ 0.696688] Freeing unused kernel memory: 4096K.
>
> Signed-off-by: Faiyaz Mohammed <[email protected]>
> ---
> changes in v2:
> - To avoid confusion, remove the memblock_dbg print and drop the
> memblock_free string, now using pr_debug to print the address ranges.
>
> mm/page_alloc.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 668edb1..395df3f 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8153,6 +8153,11 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char
> if (pages && s)
> pr_info("Freeing %s memory: %ldK\n", s, K(pages));
>
> +#ifdef CONFIG_HAVE_MEMBLOCK
> + pr_debug("%#016llx-%#016llx %pS\n",
> + __pa(start), __pa(end), (void *)_RET_IP_);
> +#endif
> +

Are we missing parentheses that the code indentation implies?
Further, I think we want to use "%pa" instead of "%llx" and
eventually drop the CONFIG_HAVE_MEMBLOCK dependency. Maybe

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b37435c274cf..e7946e5ca094 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8097,6 +8097,8 @@ EXPORT_SYMBOL(adjust_managed_page_count);

unsigned long free_reserved_area(void *start, void *end, int poison, const char *s)
{
+ const phys_addr_t pstart = __pa(start);
+ const phys_addr_t pend = __pa(end);
void *pos;
unsigned long pages = 0;

@@ -8125,9 +8127,11 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char
free_reserved_page(page);
}

- if (pages && s)
+ if (pages && s) {
pr_info("Freeing %s memory: %ldK\n",
s, pages << (PAGE_SHIFT - 10));
+ pr_debug("[%pa-%pa] %pS\n", &pstart, &pend, (void *)_RET_IP_);
+ }

return pages;
}



--
Thanks,

David / dhildenb

2021-10-13 08:47:28

by Faiyaz Mohammed

[permalink] [raw]
Subject: Re: [PATCH v2] mm: page_alloc: Add debug log in free_reserved_area for static memory



On 10/11/2021 2:04 PM, David Hildenbrand wrote:
> On 11.10.21 09:11, Faiyaz Mohammed wrote:
>> From: Faiyaz Mohammed <[email protected]>
>>
>> For INITRD and initmem memory is reserved through "memblock_reserve"
>> during boot up but it is free via "free_reserved_area" instead
>> of "memblock_free".
>> For example:
>> [    0.294848] Freeing initrd memory: 12K.
>> [    0.696688] Freeing unused kernel memory: 4096K.
>>
>> To get the start and end address of the above freed memory and to account
>> proper memblock added pr_debug log in "free_reserved_area".
>> After adding log:
>> [    0.294837] 0x00000083600000-0x00000083603000
>> free_initrd_mem+0x20/0x28
>> [    0.294848] Freeing initrd memory: 12K.
>> [    0.695246] 0x00000081600000-0x00000081a00000 free_initmem+0x70/0xc8
>> [    0.696688] Freeing unused kernel memory: 4096K.
>>
>> Signed-off-by: Faiyaz Mohammed <[email protected]>
>> ---
>> changes in v2:
>>     - To avoid confusion, remove the memblock_dbg print and drop the
>>     memblock_free string, now using pr_debug to print the address ranges.
>>
>>   mm/page_alloc.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index 668edb1..395df3f 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -8153,6 +8153,11 @@ unsigned long free_reserved_area(void *start,
>> void *end, int poison, const char
>>       if (pages && s)
>>           pr_info("Freeing %s memory: %ldK\n", s, K(pages));
>>   +#ifdef CONFIG_HAVE_MEMBLOCK
>> +        pr_debug("%#016llx-%#016llx %pS\n",
>> +            __pa(start), __pa(end), (void *)_RET_IP_);
>> +#endif
>> +
>
> Are we missing parentheses that the code indentation implies?
> Further, I think we want to use "%pa" instead of "%llx" and
> eventually drop the CONFIG_HAVE_MEMBLOCK dependency. Maybe
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index b37435c274cf..e7946e5ca094 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8097,6 +8097,8 @@ EXPORT_SYMBOL(adjust_managed_page_count);
>  
>  unsigned long free_reserved_area(void *start, void *end, int poison,
> const char *s)
>  {
> +       const phys_addr_t pstart = __pa(start);
> +       const phys_addr_t pend = __pa(end);
>         void *pos;
>         unsigned long pages = 0;
>  
> @@ -8125,9 +8127,11 @@ unsigned long free_reserved_area(void *start,
> void *end, int poison, const char
>                 free_reserved_page(page);
>         }
>  
> -       if (pages && s)
> +       if (pages && s) {
>                 pr_info("Freeing %s memory: %ldK\n",
>                         s, pages << (PAGE_SHIFT - 10));
> +               pr_debug("[%pa-%pa] %pS\n", &pstart, &pend, (void
> *)_RET_IP_);
> +       }
>  
>         return pages;
>  }
> Sure, I will update it and push again.

Thanks and regards,
Mohammed Faiyaz