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authorTang Chen <tangchen@cn.fujitsu.com>2013-02-23 04:33:44 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-24 05:50:14 +0400
commite8d1955258091e4c92d5a975ebd7fd8a98f5d30f (patch)
tree747facdf560c5ca88af4952614c7d5376ad3e4c3 /arch/x86
parentfb06bc8e5f42f38c011de0e59481f464a82380f6 (diff)
downloadlinux-e8d1955258091e4c92d5a975ebd7fd8a98f5d30f.tar.xz
acpi, memory-hotplug: parse SRAT before memblock is ready
On linux, the pages used by kernel could not be migrated. As a result, if a memory range is used by kernel, it cannot be hot-removed. So if we want to hot-remove memory, we should prevent kernel from using it. The way now used to prevent this is specify a memory range by movablemem_map boot option and set it as ZONE_MOVABLE. But when the system is booting, memblock will allocate memory, and reserve the memory for kernel. And before we parse SRAT, and know the node memory ranges, memblock is working. And it may allocate memory in ranges to be set as ZONE_MOVABLE. This memory can be used by kernel, and never be freed. So, let's parse SRAT before memblock is called first. And it is early enough. The first call of memblock_find_in_range_node() is in: setup_arch() |-->setup_real_mode() so, this patch add a function early_parse_srat() to parse SRAT, and call it before setup_real_mode() is called. NOTE: 1) early_parse_srat() is called before numa_init(), and has initialized numa_meminfo. So DO NOT clear numa_nodes_parsed in numa_init() and DO NOT zero numa_meminfo in numa_init(), otherwise we will lose memory numa info. 2) I don't know why using count of memory affinities parsed from SRAT as a return value in original acpi_numa_init(). So I add a static variable srat_mem_cnt to remember this count and use it as the return value of the new acpi_numa_init() [mhocko@suse.cz: parse SRAT before memblock is ready fix] Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Wen Congyang <wency@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Len Brown <lenb@kernel.org> Cc: "Brown, Len" <len.brown@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/setup.c13
-rw-r--r--arch/x86/mm/numa.c6
2 files changed, 13 insertions, 6 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 915f5efefcf5..9c857f05cef0 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1056,6 +1056,15 @@ void __init setup_arch(char **cmdline_p)
setup_bios_corruption_check();
#endif
+ /*
+ * In the memory hotplug case, the kernel needs info from SRAT to
+ * determine which memory is hotpluggable before allocating memory
+ * using memblock.
+ */
+ acpi_boot_table_init();
+ early_acpi_boot_init();
+ early_parse_srat();
+
#ifdef CONFIG_X86_32
printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
(max_pfn_mapped<<PAGE_SHIFT) - 1);
@@ -1101,10 +1110,6 @@ void __init setup_arch(char **cmdline_p)
/*
* Parse the ACPI tables for possible boot-time SMP configuration.
*/
- acpi_boot_table_init();
-
- early_acpi_boot_init();
-
initmem_init();
memblock_find_dma_reserve();
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index e3963f52aaea..dfd30259eb89 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -560,10 +560,12 @@ static int __init numa_init(int (*init_func)(void))
for (i = 0; i < MAX_LOCAL_APIC; i++)
set_apicid_to_node(i, NUMA_NO_NODE);
- nodes_clear(numa_nodes_parsed);
+ /*
+ * Do not clear numa_nodes_parsed or zero numa_meminfo here, because
+ * SRAT was parsed earlier in early_parse_srat().
+ */
nodes_clear(node_possible_map);
nodes_clear(node_online_map);
- memset(&numa_meminfo, 0, sizeof(numa_meminfo));
WARN_ON(memblock_set_node(0, ULLONG_MAX, MAX_NUMNODES));
numa_reset_distance();