[PATCH] x86: crash kernel reserve with reserve_early

From: Yinghai Lu
Date: Sun Nov 22 2009 - 05:26:09 EST



[PATCH] x86: crash kernel reserve with reserve_early

use find_e820_area/reserve_early instead.
will get next good one automatically with alignment

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
arch/x86/kernel/setup.c | 60 ++++++++++--------------------------------------
1 file changed, 13 insertions(+), 47 deletions(-)

Index: linux-2.6/arch/x86/kernel/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -488,42 +488,11 @@ static void __init reserve_early_setup_d

#ifdef CONFIG_KEXEC

-/**
- * Reserve @size bytes of crashkernel memory at any suitable offset.
- *
- * @size: Size of the crashkernel memory to reserve.
- * Returns the base address on success, and -1ULL on failure.
- */
-static
-unsigned long long __init find_and_reserve_crashkernel(unsigned long long size)
-{
- const unsigned long long alignment = 16<<20; /* 16M */
- unsigned long long start = 0LL;
-
- while (1) {
- int ret;
-
- start = find_e820_area(start, ULONG_MAX, size, alignment);
- if (start == -1ULL)
- return start;
-
- /* try to reserve it */
- ret = reserve_bootmem_generic(start, size, BOOTMEM_EXCLUSIVE);
- if (ret >= 0)
- return start;
-
- start += alignment;
- }
-}
-
static inline unsigned long long get_total_mem(void)
{
unsigned long long total;

- total = max_low_pfn - min_low_pfn;
-#ifdef CONFIG_HIGHMEM
- total += highend_pfn - highstart_pfn;
-#endif
+ total = max_pfn - min_low_pfn;

return total << PAGE_SHIFT;
}
@@ -532,6 +501,8 @@ static void __init reserve_crashkernel(v
{
unsigned long long total_mem;
unsigned long long crash_size, crash_base;
+ const unsigned long long alignment = 16<<20; /* 16M */
+ unsigned long long start;
int ret;

total_mem = get_total_mem();
@@ -543,21 +514,16 @@ static void __init reserve_crashkernel(v

/* 0 means: find the address automatically */
if (crash_base <= 0) {
- crash_base = find_and_reserve_crashkernel(crash_size);
- if (crash_base == -1ULL) {
- pr_info("crashkernel reservation failed. "
- "No suitable area found.\n");
- return;
- }
+ start = alignment;
} else {
- ret = reserve_bootmem_generic(crash_base, crash_size,
- BOOTMEM_EXCLUSIVE);
- if (ret < 0) {
- pr_info("crashkernel reservation failed - "
- "memory is in use\n");
- return;
- }
+ start = crash_base;
+ }
+ crash_base = find_e820_area(start, ULONG_MAX, crash_size, alignment);
+ if (crash_base == -1ULL) {
+ pr_info("crashkernel reservation failed - No suitable area found.\n");
+ return;
}
+ reserve_early(crash_base, crash_base + crash_size, "CRASH KERNEL");

printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
"for crashkernel (System RAM: %ldMB)\n",
@@ -935,6 +901,8 @@ void __init setup_arch(char **cmdline_p)

reserve_initrd();

+ reserve_crashkernel();
+
vsmp_init();

io_delay_init();
@@ -965,8 +933,6 @@ void __init setup_arch(char **cmdline_p)

initmem_init(0, max_pfn, acpi, k8);

- reserve_crashkernel();
-
#ifdef CONFIG_X86_64
/*
* dma32_reserve_bootmem() allocates bootmem which may conflict