summaryrefslogtreecommitdiffstats
path: root/arch/x86/xen/smp.c
diff options
context:
space:
mode:
authorDave Airlie <airlied@redhat.com>2012-05-07 16:09:09 +0100
committerDave Airlie <airlied@redhat.com>2012-05-07 16:09:35 +0100
commit4f256e8aa3eda15c11c3cec3ec5336e1fc579cbd (patch)
tree33c02b5e18e79756005a3edfa7c862a47de668d5 /arch/x86/xen/smp.c
parent4086b1e2b19729eebf632073b9d4ab811726d8eb (diff)
parentdc257cf154be708ecc47b8b89c12ad8cd2cc35e4 (diff)
downloadblackbird-op-linux-4f256e8aa3eda15c11c3cec3ec5336e1fc579cbd.tar.gz
blackbird-op-linux-4f256e8aa3eda15c11c3cec3ec5336e1fc579cbd.zip
Merge branch 'for-airlied' of git://people.freedesktop.org/~danvet/drm-intel into drm-core-next
Daniel prepared this branch with a back-merge as git was getting very confused about changes in intel_display.c
Diffstat (limited to 'arch/x86/xen/smp.c')
-rw-r--r--arch/x86/xen/smp.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 5fac6919b957..0503c0c493a9 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -178,6 +178,7 @@ static void __init xen_fill_possible_map(void)
static void __init xen_filter_cpu_maps(void)
{
int i, rc;
+ unsigned int subtract = 0;
if (!xen_initial_domain())
return;
@@ -192,8 +193,22 @@ static void __init xen_filter_cpu_maps(void)
} else {
set_cpu_possible(i, false);
set_cpu_present(i, false);
+ subtract++;
}
}
+#ifdef CONFIG_HOTPLUG_CPU
+ /* This is akin to using 'nr_cpus' on the Linux command line.
+ * Which is OK as when we use 'dom0_max_vcpus=X' we can only
+ * have up to X, while nr_cpu_ids is greater than X. This
+ * normally is not a problem, except when CPU hotplugging
+ * is involved and then there might be more than X CPUs
+ * in the guest - which will not work as there is no
+ * hypercall to expand the max number of VCPUs an already
+ * running guest has. So cap it up to X. */
+ if (subtract)
+ nr_cpu_ids = nr_cpu_ids - subtract;
+#endif
+
}
static void __init xen_smp_prepare_boot_cpu(void)
OpenPOWER on IntegriCloud