x86, acpi, crash, kdump: do reserve_crashkernel() after SRAT is parsed.

Memory reserved for crashkernel could be large.  So we should not allocate
this memory bottom up from the end of kernel image.

When SRAT is parsed, we will be able to know which memory is hotpluggable,
and we can avoid allocating this memory for the kernel.  So reorder
reserve_crashkernel() after SRAT is parsed.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/setup.c

@@ -1121,8 +1121,6 @@ void __init setup_arch(char **cmdline_p)
 	acpi_initrd_override((void *)initrd_start, initrd_end - initrd_start);
 #endif
 
-	reserve_crashkernel();
-
 	vsmp_init();
 
 	io_delay_init();
@@ -1135,6 +1133,13 @@ void __init setup_arch(char **cmdline_p)
 	early_acpi_boot_init();
 
 	initmem_init();
+
+	/*
+	 * Reserve memory for crash kernel after SRAT is parsed so that it
+	 * won't consume hotpluggable memory.
+	 */
+	reserve_crashkernel();
+
 	memblock_find_dma_reserve();
 
 #ifdef CONFIG_KVM_GUEST