x86: remove static boot_cpu_pda array v2

  * Remove the boot_cpu_pda array and pointer table from the data section.
    Allocate the pointer table and array during init.  do_boot_cpu()
    will reallocate the pda in node local memory and if the cpu is being
    brought up before the bootmem array is released (after_bootmem = 0),
    then it will free the initial pda.  This will happen for all cpus
    present at system startup.

    This removes 512k + 32k bytes from the data section.

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 46 insertions, 13 deletions

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 036604d3daed..bf0833487455 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -816,6 +816,43 @@ static void __cpuinit do_fork_idle(struct work_struct *work)
         complete(&c_idle->done);
 }
 
+/*
+ * Allocate node local memory for the AP pda.
+ *
+ * Must be called after the _cpu_pda pointer table is initialized.
+ */
+static int __cpuinit get_local_pda(int cpu)
+{
+        struct x8664_pda *oldpda, *newpda;
+        unsigned long size = sizeof(struct x8664_pda);
+        int node = cpu_to_node(cpu);
+
+        if (cpu_pda(cpu) && !cpu_pda(cpu)->in_bootmem)
+                return 0;
+
+        oldpda = cpu_pda(cpu);
+        newpda = kmalloc_node(size, GFP_ATOMIC, node);
+        if (!newpda) {
+                printk(KERN_ERR "Could not allocate node local PDA "
+                        "for CPU %d on node %d\n", cpu, node);
+
+                if (oldpda)
+                        return 0;       /* have a usable pda */
+                else
+                        return -1;
+        }
+
+        if (oldpda) {
+                memcpy(newpda, oldpda, size);
+                if (!after_bootmem)
+                        free_bootmem((unsigned long)oldpda, size);
+        }
+
+        newpda->in_bootmem = 0;
+        cpu_pda(cpu) = newpda;
+        return 0;
+}
+
 static int __cpuinit do_boot_cpu(int apicid, int cpu)
 /*
  * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
@@ -841,19 +878,11 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
         }
 
         /* Allocate node local memory for AP pdas */
-        if (cpu_pda(cpu) == &boot_cpu_pda[cpu]) {
-                struct x8664_pda *newpda, *pda;
-                int node = cpu_to_node(cpu);
-                pda = cpu_pda(cpu);
-                newpda = kmalloc_node(sizeof(struct x8664_pda), GFP_ATOMIC,
-                                      node);
-                if (newpda) {
-                        memcpy(newpda, pda, sizeof(struct x8664_pda));
-                        cpu_pda(cpu) = newpda;
-                } else
-                        printk(KERN_ERR
-                "Could not allocate node local PDA for CPU %d on node %d\n",
-                                cpu, node);
+        if (cpu > 0) {
+                boot_error = get_local_pda(cpu);
+                if (boot_error)
+                        goto restore_state;
+                        /* if can't get pda memory, can't start cpu */
         }
 #endif
 
@@ -972,6 +1001,8 @@ do_rest:
                 }
         }
 
+restore_state:
+
         if (boot_error) {
                 /* Try to put things back the way they were before ... */
                 unmap_cpu_to_logical_apicid(cpu);
@@ -1347,6 +1378,8 @@ __init void prefill_possible_map(void)
 
         for (i = 0; i < possible; i++)
                 cpu_set(i, cpu_possible_map);
+
+        nr_cpu_ids = possible;
 }
 
 static void __ref remove_cpu_from_maps(int cpu)