[PATCH] ia64_cleanup_topology_init

Anil
2004-06-10T23:20:40Z

Hi,
I am submitting a patch to cleanup ia64 topology_init. I will first explain how the current code is structured and what my
patch does.

In the current kernel, topology_init() is defined in arch/ia64/dig/topology.c and this file gets included if and only if CONFIG_NUMA
is _not_defined. Another version of the same function topology_init() which does exactly the same is defined under
arch/ia64/mm/numa.c and this file gets included if and only if CONFIG_NUMA is defined.
Also in numa.c register_cpu() was getting called only for online cpu's and in dig/topology.c register_cpu() was getting called for
all possible cpu's.

The attached patch combines them and moves it under arch/ia64/kernel directory. There are two reasons for doing this.
1) Allow for future expansion of the this file where in one can implement dynamic register_cpu() and register_node() for the cpu's
and node that are hot-added.
2) All sub-architecture can benefit if it is moved under ia64/kernel.

Side-effects with this patch:
With this patch register_cpu() is now called only for _online_ cpu's and not for all _possible_ cpu's as the code was doing in
arch/ia64/dig/topology.c. The reason for this is when the new cpu or node gets hot added at that time one can dynamically call these
register functions.

Please apply.

---
Patch name: ia64_cleanup_topology_init
Description: Combines the functionality of topology_init() defined in Arch/ia64/dig/topology.c and arch/ia64/mm/numa.c to
arch/ia64/kernel/topology.c
Status: Booted on tiger4 platform and compile tested for NUMA case.
---

/dev/null | 43 ------------
arch/ia64/mm/Makefile | 0
linux-2.6.7-rc2-mm2-root/arch/ia64/dig/Makefile | 4 -
linux-2.6.7-rc2-mm2-root/arch/ia64/kernel/Makefile | 3
linux-2.6.7-rc2-mm2-root/arch/ia64/kernel/topology.c | 66 +++++++++++++++++++
linux-2.6.7-rc2-mm2-root/arch/ia64/mm/numa.c | 37 ----------
6 files changed, 68 insertions(+), 85 deletions(-)

diff -puN -L arch/ia64/dig/topology.c arch/ia64/dig/topology.c~ia64_cleanup_topology /dev/null
--- linux-2.6.7-rc2-mm2/arch/ia64/dig/topology.c
+++ /dev/null 2003-09-15 06:02:17.000000000 -0700
@@ -1,43 +0,0 @@
-/*
- * arch/ia64/dig/topology.c
- * Popuate driverfs with topology information.
- * Derived entirely from i386/mach-default.c
- * Intel Corporation - Ashok Raj
- */
-#include <linux/init.h>
-#include <linux/smp.h>
-#include <linux/cpumask.h>
-#include <linux/percpu.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <asm/cpu.h>
-
-static DEFINE_PER_CPU(struct ia64_cpu, cpu_devices);
-
-/*
- * First Pass: simply borrowed code for now. Later should hook into
- * hotplug notification for node/cpu/memory as applicable
- */
-
-static int arch_register_cpu(int num)
-{
- struct node *parent = NULL;
-
-#ifdef CONFIG_NUMA
- //parent = &node_devices[cpu_to_node(num)].node;
-#endif
-
- return register_cpu(&per_cpu(cpu_devices,num).cpu, num, parent);
-}
-
-static int __init topology_init(void)
-{
- int i;
-
- for_each_cpu(i) {
- arch_register_cpu(i);
- }
- return 0;
-}
-
-subsys_initcall(topology_init);
diff -puN arch/ia64/mm/numa.c~ia64_cleanup_topology arch/ia64/mm/numa.c
--- linux-2.6.7-rc2-mm2/arch/ia64/mm/numa.c~ia64_cleanup_topology 2004-06-10 21:05:59.000000000 -0700
+++ linux-2.6.7-rc2-mm2-root/arch/ia64/mm/numa.c 2004-06-10 21:55:29.000000000 -0700
@@ -20,9 +20,6 @@
#include <asm/mmzone.h>
#include <asm/numa.h>

-static struct node *sysfs_nodes;
-static struct cpu *sysfs_cpus;
-
/*
* The following structures are usually initialized by ACPI or
* similar mechanisms and describe the NUMA characteristics of the machine.
@@ -49,37 +46,3 @@ paddr_to_nid(unsigned long paddr)

return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0);
}
-
-static int __init topology_init(void)
-{
- int i, err = 0;
-
- sysfs_nodes = kmalloc(sizeof(struct node) * numnodes, GFP_KERNEL);
- if (!sysfs_nodes) {
- err = -ENOMEM;
- goto out;
- }
- memset(sysfs_nodes, 0, sizeof(struct node) * numnodes);
-
- sysfs_cpus = kmalloc(sizeof(struct cpu) * NR_CPUS, GFP_KERNEL);
- if (!sysfs_cpus) {
- kfree(sysfs_nodes);
- err = -ENOMEM;
- goto out;
- }
- memset(sysfs_cpus, 0, sizeof(struct cpu) * NR_CPUS);
-
- for (i = 0; i < numnodes; i++)
- if ((err = register_node(&sysfs_nodes[i], i, 0)))
- goto out;
-
- for (i = 0; i < NR_CPUS; i++)
- if (cpu_online(i))
- if((err = register_cpu(&sysfs_cpus[i], i,
- &sysfs_nodes[cpu_to_node(i)])))
- goto out;
- out:
- return err;
-}
-
-__initcall(topology_init);
diff -puN /dev/null arch/ia64/kernel/topology.c
--- /dev/null 2003-09-15 06:02:17.000000000 -0700
+++ linux-2.6.7-rc2-mm2-root/arch/ia64/kernel/topology.c 2004-06-10 22:07:02.000000000 -0700
@@ -0,0 +1,66 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * This file contains NUMA specific variables and functions which can
+ * be split away from DISCONTIGMEM and are used on NUMA machines with
+ * contiguous memory.
+ * 2002/08/07 Erich Focht <efocht@ess.nec.de>
+ * Popuate driverfs with topology information, Derived entirely from i386/mach-default.c
+ * Intel Corporation - Ashok Raj
+ */
+
+#include <linux/config.h>
+#include <linux/cpu.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/node.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <asm/mmzone.h>
+#include <asm/numa.h>
+#include <asm/cpu.h>
+
+static struct ia64_cpu *sysfs_cpus;
+
+#ifdef CONFIG_NUMA
+static struct node *sysfs_nodes;
+#define SYSFS_CPU_NODE(i) (&sysfs_nodes[cpu_to_node(i)])
+#else
+#define SYSFS_CPU_NODE(i) (NULL)
+#endif
+
+static int __init topology_init(void)
+{
+ int i, err = 0;
+
+#ifdef CONFIG_NUMA
+ sysfs_nodes = kmalloc(sizeof(struct node) * numnodes, GFP_KERNEL);
+ if (!sysfs_nodes) {
+ err = -ENOMEM;
+ goto out;
+ }
+ memset(sysfs_nodes, 0, sizeof(struct node) * numnodes);
+
+ for (i = 0; i < numnodes; i++)
+ if ((err = register_node(&sysfs_nodes[i], i, 0)))
+ goto out;
+#endif
+
+ sysfs_cpus = kmalloc(sizeof(struct ia64_cpu) * NR_CPUS, GFP_KERNEL);
+ if (!sysfs_cpus) {
+ err = -ENOMEM;
+ goto out;
+ }
+ memset(sysfs_cpus, 0, sizeof(struct ia64_cpu) * NR_CPUS);
+
+ for_each_online_cpu(i)
+ if((err = register_cpu(&sysfs_cpus[i].cpu, i,
+ SYSFS_CPU_NODE(i))))
+ goto out;
+ out:
+ return err;
+}
+
+__initcall(topology_init);
diff -puN arch/ia64/dig/Makefile~ia64_cleanup_topology arch/ia64/dig/Makefile
--- linux-2.6.7-rc2-mm2/arch/ia64/dig/Makefile~ia64_cleanup_topology 2004-06-10 21:53:34.000000000 -0700
+++ linux-2.6.7-rc2-mm2-root/arch/ia64/dig/Makefile 2004-06-10 21:54:08.000000000 -0700
@@ -7,8 +7,4 @@

obj-y := setup.o

-ifndef CONFIG_NUMA
-obj-$(CONFIG_IA64_DIG) += topology.o
-endif
-
obj-$(CONFIG_IA64_GENERIC) += machvec.o
diff -puN arch/ia64/mm/Makefile~ia64_cleanup_topology arch/ia64/mm/Makefile
diff -puN arch/ia64/kernel/Makefile~ia64_cleanup_topology arch/ia64/kernel/Makefile
--- linux-2.6.7-rc2-mm2/arch/ia64/kernel/Makefile~ia64_cleanup_topology 2004-06-10 22:01:32.000000000 -0700
+++ linux-2.6.7-rc2-mm2-root/arch/ia64/kernel/Makefile 2004-06-10 22:02:21.000000000 -0700
@@ -6,7 +6,8 @@ extra-y := head.o init_task.o vmlinux.ld

obj-y := acpi.o entry.o efi.o efi_stub.o gate-data.o fsys.o ia64_ksyms.o irq.o irq_ia64.o \
irq_lsapic.o ivt.o machvec.o pal.o patch.o process.o perfmon.o ptrace.o sal.o \
- salinfo.o semaphore.o setup.o signal.o sys_ia64.o time.o traps.o unaligned.o unwind.o mca.o mca_asm.o
+ salinfo.o semaphore.o setup.o signal.o sys_ia64.o time.o traps.o unaligned.o \
+ unwind.o mca.o mca_asm.o topology.o

obj-$(CONFIG_IA64_BRL_EMU) += brl_emu.o
obj-$(CONFIG_IA64_GENERIC) += acpi-ext.o

_

Thanks,

-Anil Keshavamurthy
Sr. Software Engineer
Linux OS Technology Team
Intel Corp.
(w) 503-712-4476