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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-07 02:11:45 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-07 02:11:45 +0300
commite913c4a4c21cd83317fafe63bfdc9d34d2910114 (patch)
tree57c951ecfc3556b448d033f5327112e7c3162cfe /arch
parent8f147727030bf9e81331ab9b8f42d4611bb6a3d9 (diff)
parentb9ac3849af412fd3887d7652bdbabf29d2aecc16 (diff)
downloadlinux-e913c4a4c21cd83317fafe63bfdc9d34d2910114.tar.xz
Merge branch 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 kdump update from Ingo Molnar: "This includes two changes: - Raise the crash kernel reservation limit from from ~896MB to ~4GB. Only very old (and already known-broken) kexec-tools is supposed to be affected by this negatively. - Allow higher than 4GB crash kernel allocations when low allocations fail" * 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kdump: Fall back to reserve high crashkernel memory x86/kdump: Have crashkernel=X reserve under 4G by default
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/setup.c32
1 files changed, 19 insertions, 13 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 3773905cd2c1..905dae880563 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -71,6 +71,7 @@
#include <linux/tboot.h>
#include <linux/jiffies.h>
#include <linux/mem_encrypt.h>
+#include <linux/sizes.h>
#include <linux/usb/xhci-dbgp.h>
#include <video/edid.h>
@@ -448,18 +449,17 @@ static void __init memblock_x86_reserve_range_setup_data(void)
#ifdef CONFIG_KEXEC_CORE
/* 16M alignment for crash kernel regions */
-#define CRASH_ALIGN (16 << 20)
+#define CRASH_ALIGN SZ_16M
/*
* Keep the crash kernel below this limit. On 32 bits earlier kernels
* would limit the kernel to the low 512 MiB due to mapping restrictions.
- * On 64bit, old kexec-tools need to under 896MiB.
*/
#ifdef CONFIG_X86_32
-# define CRASH_ADDR_LOW_MAX (512 << 20)
-# define CRASH_ADDR_HIGH_MAX (512 << 20)
+# define CRASH_ADDR_LOW_MAX SZ_512M
+# define CRASH_ADDR_HIGH_MAX SZ_512M
#else
-# define CRASH_ADDR_LOW_MAX (896UL << 20)
+# define CRASH_ADDR_LOW_MAX SZ_4G
# define CRASH_ADDR_HIGH_MAX MAXMEM
#endif
@@ -541,21 +541,27 @@ static void __init reserve_crashkernel(void)
}
/* 0 means: find the address automatically */
- if (crash_base <= 0) {
+ if (!crash_base) {
/*
* Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
- * as old kexec-tools loads bzImage below that, unless
- * "crashkernel=size[KMG],high" is specified.
+ * crashkernel=x,high reserves memory over 4G, also allocates
+ * 256M extra low memory for DMA buffers and swiotlb.
+ * But the extra memory is not required for all machines.
+ * So try low memory first and fall back to high memory
+ * unless "crashkernel=size[KMG],high" is specified.
*/
- crash_base = memblock_find_in_range(CRASH_ALIGN,
- high ? CRASH_ADDR_HIGH_MAX
- : CRASH_ADDR_LOW_MAX,
- crash_size, CRASH_ALIGN);
+ if (!high)
+ crash_base = memblock_find_in_range(CRASH_ALIGN,
+ CRASH_ADDR_LOW_MAX,
+ crash_size, CRASH_ALIGN);
+ if (!crash_base)
+ crash_base = memblock_find_in_range(CRASH_ALIGN,
+ CRASH_ADDR_HIGH_MAX,
+ crash_size, CRASH_ALIGN);
if (!crash_base) {
pr_info("crashkernel reservation failed - No suitable area found.\n");
return;
}
-
} else {
unsigned long long start;