[PATCH] i386: Use per-cpu variables for GDT, PDA

Allocating PDA and GDT at boot is a pain.  Using simple per-cpu variables adds
happiness (although we need the GDT page-aligned for Xen, which we do in a
followup patch).

[akpm@linux-foundation.org: build fix]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 1 insertions, 20 deletions

diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 7b14e88b555f..b36a5f174cc9 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -808,13 +808,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
         if (IS_ERR(idle))
                 panic("failed fork for CPU %d", cpu);
 
-        /* Pre-allocate and initialize the CPU's GDT and PDA so it
-           doesn't have to do any memory allocation during the
-           delicate CPU-bringup phase. */
-        if (!init_gdt(cpu, idle)) {
-                printk(KERN_INFO "Couldn't allocate GDT/PDA for CPU %d\n", cpu);
-                return -1;      /* ? */
-        }
+        init_gdt(cpu, idle);
 
         idle->thread.eip = (unsigned long) start_secondary;
         /* start_eip had better be page-aligned! */
@@ -940,7 +934,6 @@ static int __cpuinit __smp_prepare_cpu(int cpu)
         DECLARE_COMPLETION_ONSTACK(done);
         struct warm_boot_cpu_info info;
         int     apicid, ret;
-        struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
 
         apicid = x86_cpu_to_apicid[cpu];
         if (apicid == BAD_APICID) {
@@ -948,18 +941,6 @@ static int __cpuinit __smp_prepare_cpu(int cpu)
                 goto exit;
         }
 
-        /*
-         * the CPU isn't initialized at boot time, allocate gdt table here.
-         * cpu_init will initialize it
-         */
-        if (!cpu_gdt_descr->address) {
-                cpu_gdt_descr->address = get_zeroed_page(GFP_KERNEL);
-                if (!cpu_gdt_descr->address)
-                        printk(KERN_CRIT "CPU%d failed to allocate GDT\n", cpu);
-                        ret = -ENOMEM;
-                        goto exit;
-        }
-
         info.complete = &done;
         info.apicid = apicid;
         info.cpu = cpu;