[PATCH v3] mm: page_alloc: Add debug log in free_reserved_area for static memory

From: Faiyaz Mohammed
Date: Thu Oct 14 2021 - 03:13:21 EST


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 <faiyazm@xxxxxxxxxxxxxx>
---
changes in v3:
- Update the format specifier.
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 | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b37435c..13adda5 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 +8127,12 @@ 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;
}
--
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