[PATCH v12 1/9] x86: kdump: move CRASH_ALIGN to 2M

Chen Zhou
2020-09-07T17:21:52Z

CONFIG_PHYSICAL_ALIGN can be selected from 2M to 16M and default
value is 2M, so move CRASH_ALIGN to 2M, with smaller value reservation
can have more chance to succeed.
And replace the hard-coded alignment with macro CRASH_ALIGN in function
reserve_crashkernel().

Suggested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
---
arch/x86/include/asm/kexec.h | 3 +++
arch/x86/kernel/setup.c | 5 +----
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 6802c59e8252..83f200dd54a1 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -18,6 +18,9 @@

# define KEXEC_CONTROL_CODE_MAX_SIZE 2048

+/* 2M alignment for crash kernel regions */
+#define CRASH_ALIGN SZ_2M
+
#ifndef __ASSEMBLY__

#include <linux/string.h>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 3511736fbc74..296294ad0dd8 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -402,9 +402,6 @@ static void __init memblock_x86_reserve_range_setup_data(void)

#ifdef CONFIG_KEXEC_CORE

-/* 16M alignment for crash kernel regions */
-#define CRASH_ALIGN SZ_16M
-
/*
* Keep the crash kernel below this limit.
*
@@ -530,7 +527,7 @@ static void __init reserve_crashkernel(void)

start = memblock_find_in_range(crash_base,
crash_base + crash_size,
- crash_size, 1 << 20);
+ crash_size, CRASH_ALIGN);
if (start != crash_base) {
pr_info("crashkernel reservation failed - memory is in use.\n");
return;
--
2.20.1