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From: Wupeng Ma <mawupeng1@huawei.com>
To: <akpm@linux-foundation.org>, <rppt@kernel.org>
CC: <linux-mm@kvack.org>, <mawupeng1@huawei.com>,
	<linux-kernel@vger.kernel.org>
Subject: [PATCH] efi: Disable mirror feature during crashkernel
Date: Tue, 9 Jan 2024 12:15:36 +0800
Message-ID: <20240109041536.3903042-1-mawupeng1@huawei.com>
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From: Ma Wupeng <mawupeng1@huawei.com>

If system have no mirrored memory or use crashkernel.high while
kernelcore=mirror is enabled in cmdline, during crashkernel,
there will be limited mirrored memory and this usually lead to
OOM.

To solve this problem, disable mirror feature during crashkernel.

Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
---
 mm/mm_init.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 077bfe393b5e..513bad672708 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -26,6 +26,7 @@
 #include <linux/pgtable.h>
 #include <linux/swap.h>
 #include <linux/cma.h>
+#include <linux/crash_dump.h>
 #include "internal.h"
 #include "slab.h"
 #include "shuffle.h"
@@ -381,6 +382,11 @@ static void __init find_zone_movable_pfns_for_nodes(void)
 			goto out;
 		}
 
+		if (is_kdump_kernel()) {
+			pr_warn("The system is under kdump, ignore kernelcore=mirror.\n");
+			goto out;
+		}
+
 		for_each_mem_region(r) {
 			if (memblock_is_mirror(r))
 				continue;
-- 
2.25.1