linux-kernel - [PATCH v2] mm: page_alloc: Add debug log in free_reserved

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Date:   Mon, 11 Oct 2021 12:41:19 +0530
From:   Faiyaz Mohammed <quic_faiyazm@...eaurora.org>
To:     akpm@...ux-foundation.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, david@...hat.com
Cc:     guptap@...eaurora.org, Faiyaz Mohammed <faiyazm@...eaurora.org>
Subject: [PATCH v2] mm: page_alloc: Add debug log in free_reserved_area for static memory

From: Faiyaz Mohammed <faiyazm@...eaurora.org>

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@...eaurora.org>
---
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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