[Xen-changelog] Ensure we initialise the cpu_present_map before

[Xen patchbot -unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 5e111356ba17602f474e36da6571de490157981a
# Parent  2acbe70dd418a963fc15d6b3f5bd0ecf76881f50
Ensure we initialise the cpu_present_map before
topology_init() is called. In latest Linux kernels it
iterates over cpu_present_map rather than cpu_possible_map.

Also, save/restore should really iterate over
possible cpus, not present ones (not that it really matters,
but it's a small cleanup).

Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>

diff -r 2acbe70dd418 -r 5e111356ba17 
linux-2.6-xen-sparse/arch/xen/kernel/reboot.c
--- a/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c     Tue Nov 15 16:30:55 2005
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/reboot.c     Tue Nov 15 17:43:28 2005
@@ -188,7 +188,7 @@
        xenbus_resume();
 
 #ifdef CONFIG_SMP
-       for_each_present_cpu(i)
+       for_each_cpu(i)
                vcpu_prepare(i);
 
  out_reenable_cpus:
diff -r 2acbe70dd418 -r 5e111356ba17 
linux-2.6-xen-sparse/arch/xen/kernel/smpboot.c
--- a/linux-2.6-xen-sparse/arch/xen/kernel/smpboot.c    Tue Nov 15 16:30:55 2005
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/smpboot.c    Tue Nov 15 17:43:28 2005
@@ -277,6 +277,18 @@
 
 #ifdef CONFIG_HOTPLUG_CPU
 
+/*
+ * Initialize cpu_present_map late to skip SMP boot code in init/main.c.
+ * But do it early enough to catch critical for_each_present_cpu() loops
+ * in i386-specific code.
+ */
+static int __init initialize_cpu_present_map(void)
+{
+       cpu_present_map = cpu_possible_map;
+       return 0;
+}
+core_initcall(initialize_cpu_present_map);
+
 static void vcpu_hotplug(unsigned int cpu)
 {
        int err;
@@ -293,7 +305,6 @@
        }
 
        if (strcmp(state, "online") == 0) {
-               cpu_set(cpu, cpu_present_map);
                (void)cpu_up(cpu);
        } else if (strcmp(state, "offline") == 0) {
                (void)cpu_down(cpu);

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog