[patch 3/3] x86_64: Node local pda take 2 -- node local pda allocation

From: Ravikiran G Thirumalai
Date: Wed Dec 14 2005 - 21:37:13 EST


Patch uses a static PDA array early at boot and reallocates processor PDA
with node local memory when kmalloc is ready, just before pda_init.
The boot_cpu_pda is needed since the cpu_pda is used even before pda_init for
that cpu is called.
(pda_init is called when APs are brought on at rest_init(). But
setup_per_cpu_areas is called early in start_kernel and
sched_init uses the per-cpu offset table early)

Signed-off-by: Ravikiran Thirumalai <kiran@xxxxxxxxxxxx>
Signed-off-by: Shai Fultheim <shai@xxxxxxxxxxxx>

Index: linux-2.6.15-rc4/arch/x86_64/kernel/head64.c
===================================================================
--- linux-2.6.15-rc4.orig/arch/x86_64/kernel/head64.c 2005-12-12 01:11:01.000000000 -0800
+++ linux-2.6.15-rc4/arch/x86_64/kernel/head64.c 2005-12-12 02:24:02.000000000 -0800
@@ -92,6 +92,11 @@
memcpy(init_level4_pgt, boot_level4_pgt, PTRS_PER_PGD*sizeof(pgd_t));
asm volatile("movq %0,%%cr3" :: "r" (__pa_symbol(&init_level4_pgt)));

+#ifdef CONFIG_NUMA
+ for (i = 0; i < NR_CPUS; i++)
+ cpu_pda(i) = &boot_cpu_pda[i];
+#endif
+
pda_init(0);
copy_bootdata(real_mode_data);
#ifdef CONFIG_SMP
Index: linux-2.6.15-rc4/arch/x86_64/kernel/setup64.c
===================================================================
--- linux-2.6.15-rc4.orig/arch/x86_64/kernel/setup64.c 2005-12-12 02:24:00.000000000 -0800
+++ linux-2.6.15-rc4/arch/x86_64/kernel/setup64.c 2005-12-12 02:24:02.000000000 -0800
@@ -30,7 +30,12 @@

cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;

-struct x8664_pda _cpu_pda[NR_CPUS] __cacheline_aligned;
+#ifdef CONFIG_NUMA
+struct x8664_pda *_cpu_pda[NR_CPUS] __read_mostly;
+struct x8664_pda boot_cpu_pda[NR_CPUS] __cacheline_aligned;
+#else
+struct x8664_pda _cpu_pda[NR_CPUS] __read_mostly;
+#endif

struct desc_ptr idt_descr = { 256 * 16, (unsigned long) idt_table };

@@ -119,6 +124,25 @@
{
struct x8664_pda *pda = cpu_pda(cpu);

+#ifdef CONFIG_NUMA
+ /* Allocate node local memory for AP pdas */
+ if (cpu) {
+ struct x8664_pda *newpda;
+ newpda = kmalloc_node(sizeof (struct x8664_pda), GFP_ATOMIC,
+ cpu_to_node(cpu));
+ if (newpda) {
+ printk("Allocating node local PDA for cpu %d at 0x%lx\n",
+ cpu, (unsigned long) newpda);
+ memcpy(newpda, pda, sizeof (struct x8664_pda));
+ pda = newpda;
+ cpu_pda(cpu) = pda;
+ }
+ else
+ printk("Could not allocate node local PDA for cpu %d\n",
+ cpu);
+ }
+#endif
+
/* Setup up data that may be needed in __get_free_pages early */
asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0));
wrmsrl(MSR_GS_BASE, pda);
Index: linux-2.6.15-rc4/include/asm-x86_64/pda.h
===================================================================
--- linux-2.6.15-rc4.orig/include/asm-x86_64/pda.h 2005-12-12 02:24:00.000000000 -0800
+++ linux-2.6.15-rc4/include/asm-x86_64/pda.h 2005-12-12 02:24:02.000000000 -0800
@@ -27,9 +27,14 @@
#define IRQSTACK_ORDER 2
#define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER)

+#ifdef CONFIG_NUMA
+extern struct x8664_pda *_cpu_pda[];
+extern struct x8664_pda boot_cpu_pda[];
+#define cpu_pda(i) (_cpu_pda[i])
+#else
extern struct x8664_pda _cpu_pda[];
-
#define cpu_pda(i) (&_cpu_pda[i])
+#endif

/*
* There is no fast way to get the base address of the PDA, all the accesses
-
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