[PATCH/RFC 2/6] numa: x86_64: use generic percpu var numa_node_id() implementation

Lee Schermerhorn
2009-11-13T21:12:53Z

Against: 2.6.32-rc5-mmotm-091101-1001

x86 arch specific changes to use generic numa_node_id() based on
generic percpu variable infrastructure. Back out x86's custom
version of numa_node_id()

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
[Christoph's signoff here?]

V0: based on:
# From cl@linux-foundation.org Wed Nov 4 10:36:12 2009
# Date: Wed, 4 Nov 2009 12:35:14 -0500 (EST)
# From: Christoph Lameter <cl@linux-foundation.org>
# To: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
# Subject: Re: [PATCH/RFC] slab: handle memoryless nodes efficiently
#
# I have a very early form of a draft of a patch here that genericizes
# numa_node_id(). Uses the new generic this_cpu_xxx stuff.
#
# Not complete.

V1:
+ split out x86-specific changes from generic.
+ change 'node_number' => 'numa_node' in x86 arch code
+ define __this_cpu_read in x86 asm/percpu.h
+ change x86/kernel/setup_percpu.c to use early_cpu_to_node() to
setup 'numa_node' as cpu_to_node() now depends on the per cpu var.
[I think! What about cpu_to_node() func in x86/mm/numa_64.c ???]

V2:
+ cpu_to_node() => early_cpu_to_node(); incomplete change in V01
+ x86 arch define USE_PERCPU_NUMA_NODE_ID.

arch/x86/Kconfig | 4 ++++
arch/x86/include/asm/percpu.h | 2 ++
arch/x86/include/asm/topology.h | 13 +------------
arch/x86/kernel/cpu/common.c | 6 +++---
arch/x86/kernel/setup_percpu.c | 4 ++--
arch/x86/mm/numa_64.c | 5 +----
6 files changed, 13 insertions(+), 21 deletions(-)

Index: linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/include/asm/topology.h
===================================================================
--- linux-2.6.32-rc5-mmotm-091101-1001.orig/arch/x86/include/asm/topology.h
+++ linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/include/asm/topology.h
@@ -53,33 +53,22 @@
extern int cpu_to_node_map[];

/* Returns the number of the node containing CPU 'cpu' */
-static inline int cpu_to_node(int cpu)
+static inline int early_cpu_to_node(int cpu)
{
return cpu_to_node_map[cpu];
}
-#define early_cpu_to_node(cpu) cpu_to_node(cpu)

#else /* CONFIG_X86_64 */

/* Mappings between logical cpu number and node number */
DECLARE_EARLY_PER_CPU(int, x86_cpu_to_node_map);

-/* Returns the number of the current Node. */
-DECLARE_PER_CPU(int, node_number);
-#define numa_node_id() percpu_read(node_number)
-
#ifdef CONFIG_DEBUG_PER_CPU_MAPS
extern int cpu_to_node(int cpu);
extern int early_cpu_to_node(int cpu);

#else /* !CONFIG_DEBUG_PER_CPU_MAPS */

-/* Returns the number of the node containing CPU 'cpu' */
-static inline int cpu_to_node(int cpu)
-{
- return per_cpu(x86_cpu_to_node_map, cpu);
-}
-
/* Same function but used if called before per_cpu areas are setup */
static inline int early_cpu_to_node(int cpu)
{
Index: linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/mm/numa_64.c
===================================================================
--- linux-2.6.32-rc5-mmotm-091101-1001.orig/arch/x86/mm/numa_64.c
+++ linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/mm/numa_64.c
@@ -33,9 +33,6 @@ int numa_off __initdata;
static unsigned long __initdata nodemap_addr;
static unsigned long __initdata nodemap_size;

-DEFINE_PER_CPU(int, node_number) = 0;
-EXPORT_PER_CPU_SYMBOL(node_number);
-
/*
* Map cpu index to node index
*/
@@ -816,7 +813,7 @@ void __cpuinit numa_set_node(int cpu, in
per_cpu(x86_cpu_to_node_map, cpu) = node;

if (node != NUMA_NO_NODE)
- per_cpu(node_number, cpu) = node;
+ per_cpu(numa_node, cpu) = node;
}

void __cpuinit numa_clear_node(int cpu)
Index: linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/include/asm/percpu.h
===================================================================
--- linux-2.6.32-rc5-mmotm-091101-1001.orig/arch/x86/include/asm/percpu.h
+++ linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/include/asm/percpu.h
@@ -150,10 +150,12 @@ do { \
#define percpu_or(var, val) percpu_to_op("or", var, val)
#define percpu_xor(var, val) percpu_to_op("xor", var, val)

+#define __this_cpu_read(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define __this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define __this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
#define __this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(pcp))

+#define __this_cpu_write(pcp, val) percpu_to_op("mov", (pcp), val)
#define __this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
#define __this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
#define __this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
Index: linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/kernel/cpu/common.c
===================================================================
--- linux-2.6.32-rc5-mmotm-091101-1001.orig/arch/x86/kernel/cpu/common.c
+++ linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/kernel/cpu/common.c
@@ -1105,9 +1105,9 @@ void __cpuinit cpu_init(void)
oist = &per_cpu(orig_ist, cpu);

#ifdef CONFIG_NUMA
- if (cpu != 0 && percpu_read(node_number) == 0 &&
- cpu_to_node(cpu) != NUMA_NO_NODE)
- percpu_write(node_number, cpu_to_node(cpu));
+ if (cpu != 0 && percpu_read(numa_node) == 0 &&
+ early_cpu_to_node(cpu) != NUMA_NO_NODE)
+ set_numa_node(early_cpu_to_node(cpu));
#endif

me = current;
Index: linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/kernel/setup_percpu.c
===================================================================
--- linux-2.6.32-rc5-mmotm-091101-1001.orig/arch/x86/kernel/setup_percpu.c
+++ linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/kernel/setup_percpu.c
@@ -258,10 +258,10 @@ void __init setup_per_cpu_areas(void)

#if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
/*
- * make sure boot cpu node_number is right, when boot cpu is on the
+ * make sure boot cpu numa_node is right, when boot cpu is on the
* node that doesn't have mem installed
*/
- per_cpu(node_number, boot_cpu_id) = cpu_to_node(boot_cpu_id);
+ per_cpu(numa_node, boot_cpu_id) = early_cpu_to_node(boot_cpu_id);
#endif

/* Setup node to cpumask map */
Index: linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/Kconfig
===================================================================
--- linux-2.6.32-rc5-mmotm-091101-1001.orig/arch/x86/Kconfig
+++ linux-2.6.32-rc5-mmotm-091101-1001/arch/x86/Kconfig
@@ -1677,6 +1677,10 @@ config HAVE_ARCH_EARLY_PFN_TO_NID
def_bool X86_64
depends on NUMA

+config USE_PERCPU_NUMA_NODE_ID
+ def_bool y
+ depends on NUMA
+
menu "Power management and ACPI options"

config ARCH_HIBERNATION_HEADER