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authorTang Chen2013-02-22 16:33:49 -0800
committerLinus Torvalds2013-02-23 17:50:14 -0800
commit01a178a94e8eaec351b29ee49fbb3d1c124cb7fb (patch)
treede978b65bf5d4a05c78cb5ce1180dc3fb04bd12d /arch/x86
parent27168d38fa209073219abedbe6a9de7ba9acbfad (diff)
acpi, memory-hotplug: support getting hotplug info from SRAT
We now provide an option for users who don't want to specify physical memory address in kernel commandline. /* * For movablemem_map=acpi: * * SRAT: |_____| |_____| |_________| |_________| ...... * node id: 0 1 1 2 * hotpluggable: n y y n * movablemem_map: |_____| |_________| * * Using movablemem_map, we can prevent memblock from allocating memory * on ZONE_MOVABLE at boot time. */ So user just specify movablemem_map=acpi, and the kernel will use hotpluggable info in SRAT to determine which memory ranges should be set as ZONE_MOVABLE. If all the memory ranges in SRAT is hotpluggable, then no memory can be used by kernel. But before parsing SRAT, memblock has already reserve some memory ranges for other purposes, such as for kernel image, and so on. We cannot prevent kernel from using these memory. So we need to exclude these ranges even if these memory is hotpluggable. Furthermore, there could be several memory ranges in the single node which the kernel resides in. We may skip one range that have memory reserved by memblock, but if the rest of memory is too small, then the kernel will fail to boot. So, make the whole node which the kernel resides in un-hotpluggable. Then the kernel has enough memory to use. NOTE: Using this way will cause NUMA performance down because the whole node will be set as ZONE_MOVABLE, and kernel cannot use memory on it. If users don't want to lose NUMA performance, just don't use it. [akpm@linux-foundation.org: fix warning] [akpm@linux-foundation.org: use strcmp()] Signed-off-by: Tang Chen <tangchen@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/mm/srat.c71
1 files changed, 66 insertions, 5 deletions
diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index 3e90039e52e0..79836d01f789 100644
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -142,16 +142,72 @@ static inline int save_add_info(void) {return 0;}
#endif
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
-static void __init handle_movablemem(int node, u64 start, u64 end)
+static void __init
+handle_movablemem(int node, u64 start, u64 end, u32 hotpluggable)
{
- int overlap;
+ int overlap, i;
unsigned long start_pfn, end_pfn;
start_pfn = PFN_DOWN(start);
end_pfn = PFN_UP(end);
/*
- * For movablecore_map=nn[KMG]@ss[KMG]:
+ * For movablemem_map=acpi:
+ *
+ * SRAT: |_____| |_____| |_________| |_________| ......
+ * node id: 0 1 1 2
+ * hotpluggable: n y y n
+ * movablemem_map: |_____| |_________|
+ *
+ * Using movablemem_map, we can prevent memblock from allocating memory
+ * on ZONE_MOVABLE at boot time.
+ *
+ * Before parsing SRAT, memblock has already reserve some memory ranges
+ * for other purposes, such as for kernel image. We cannot prevent
+ * kernel from using these memory, so we need to exclude these memory
+ * even if it is hotpluggable.
+ * Furthermore, to ensure the kernel has enough memory to boot, we make
+ * all the memory on the node which the kernel resides in
+ * un-hotpluggable.
+ */
+ if (hotpluggable && movablemem_map.acpi) {
+ /* Exclude ranges reserved by memblock. */
+ struct memblock_type *rgn = &memblock.reserved;
+
+ for (i = 0; i < rgn->cnt; i++) {
+ if (end <= rgn->regions[i].base ||
+ start >= rgn->regions[i].base +
+ rgn->regions[i].size)
+ continue;
+
+ /*
+ * If the memory range overlaps the memory reserved by
+ * memblock, then the kernel resides in this node.
+ */
+ node_set(node, movablemem_map.numa_nodes_kernel);
+
+ goto out;
+ }
+
+ /*
+ * If the kernel resides in this node, then the whole node
+ * should not be hotpluggable.
+ */
+ if (node_isset(node, movablemem_map.numa_nodes_kernel))
+ goto out;
+
+ insert_movablemem_map(start_pfn, end_pfn);
+
+ /*
+ * numa_nodes_hotplug nodemask represents which nodes are put
+ * into movablemem_map.map[].
+ */
+ node_set(node, movablemem_map.numa_nodes_hotplug);
+ goto out;
+ }
+
+ /*
+ * For movablemem_map=nn[KMG]@ss[KMG]:
*
* SRAT: |_____| |_____| |_________| |_________| ......
* node id: 0 1 1 2
@@ -160,6 +216,8 @@ static void __init handle_movablemem(int node, u64 start, u64 end)
*
* Using movablemem_map, we can prevent memblock from allocating memory
* on ZONE_MOVABLE at boot time.
+ *
+ * NOTE: In this case, SRAT info will be ingored.
*/
overlap = movablemem_map_overlap(start_pfn, end_pfn);
if (overlap >= 0) {
@@ -187,9 +245,12 @@ static void __init handle_movablemem(int node, u64 start, u64 end)
*/
insert_movablemem_map(start_pfn, end_pfn);
}
+out:
+ return;
}
#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
-static inline void handle_movablemem(int node, u64 start, u64 end)
+static inline void
+handle_movablemem(int node, u64 start, u64 end, u32 hotpluggable)
{
}
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
@@ -234,7 +295,7 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
(unsigned long long) start, (unsigned long long) end - 1,
hotpluggable ? "Hot Pluggable": "");
- handle_movablemem(node, start, end);
+ handle_movablemem(node, start, end, hotpluggable);
return 0;
out_err_bad_srat: