x86, kdump: Retore crashkernel= to allocate under 896M
Vivek found old kexec-tools does not work new kernel anymore.
So change back crashkernel= back to old behavoir, and add crashkernel_high=
to let user decide if buffer could be above 4G, and also new kexec-tools will
be needed.
-v2: let crashkernel=X override crashkernel_high=
update description about _high will be ignored by crashkernel=X
-v3: update description about kernel-parameters.txt according to Vivek.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1366089828-19692-4-git-send-email-yinghai@kernel.org
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 1234920..a85a144 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -507,11 +507,14 @@
/*
* 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_KERNEL_ADDR_MAX (512 << 20)
+# define CRASH_KERNEL_ADDR_LOW_MAX (512 << 20)
+# define CRASH_KERNEL_ADDR_HIGH_MAX (512 << 20)
#else
-# define CRASH_KERNEL_ADDR_MAX MAXMEM
+# define CRASH_KERNEL_ADDR_LOW_MAX (896UL<<20)
+# define CRASH_KERNEL_ADDR_HIGH_MAX MAXMEM
#endif
static void __init reserve_crashkernel_low(void)
@@ -525,6 +528,7 @@
int ret;
total_low_mem = memblock_mem_size(1UL<<(32-PAGE_SHIFT));
+ /* crashkernel_low=YM */
ret = parse_crashkernel_low(boot_command_line, total_low_mem,
&low_size, &base);
if (ret != 0) {
@@ -569,14 +573,22 @@
const unsigned long long alignment = 16<<20; /* 16M */
unsigned long long total_mem;
unsigned long long crash_size, crash_base;
+ bool high = false;
int ret;
total_mem = memblock_phys_mem_size();
+ /* crashkernel=XM */
ret = parse_crashkernel(boot_command_line, total_mem,
&crash_size, &crash_base);
- if (ret != 0 || crash_size <= 0)
- return;
+ if (ret != 0 || crash_size <= 0) {
+ /* crashkernel_high=XM */
+ ret = parse_crashkernel_high(boot_command_line, total_mem,
+ &crash_size, &crash_base);
+ if (ret != 0 || crash_size <= 0)
+ return;
+ high = true;
+ }
/* 0 means: find the address automatically */
if (crash_base <= 0) {
@@ -584,7 +596,9 @@
* kexec want bzImage is below CRASH_KERNEL_ADDR_MAX
*/
crash_base = memblock_find_in_range(alignment,
- CRASH_KERNEL_ADDR_MAX, crash_size, alignment);
+ high ? CRASH_KERNEL_ADDR_HIGH_MAX :
+ CRASH_KERNEL_ADDR_LOW_MAX,
+ crash_size, alignment);
if (!crash_base) {
pr_info("crashkernel reservation failed - No suitable area found.\n");