--- /dev/null
+From: Gerald Schaefer <geraldsc@de.ibm.com>
+Subject: kernel: fix cpu topology support
+References: bnc#464466
+
+Symptom: CPU topology changes aren't recognized by the scheduler.
+Problem: The common code scheduler used to have a hook which could be
+ called from architecture code to trigger a rebuild of all
+ scheduling domains when cpu topology changed. This hook got
+ removed errorneously. So cpu topology change notifications
+ got lost.
+Solution: Readd the hook. This patch also removes some unused code
+ from the s390 specific cpu topology code.
+
+Acked-by: John Jolly <jjolly@suse.de>
+---
+ arch/s390/kernel/topology.c | 35 ++++++++++-------------------------
+ include/linux/topology.h | 2 +-
+ kernel/sched.c | 16 +++++++++++++---
+ 3 files changed, 24 insertions(+), 29 deletions(-)
+
+--- a/arch/s390/kernel/topology.c
++++ b/arch/s390/kernel/topology.c
+@@ -14,6 +14,7 @@
+ #include <linux/workqueue.h>
+ #include <linux/cpu.h>
+ #include <linux/smp.h>
++#include <linux/cpuset.h>
+ #include <asm/delay.h>
+ #include <asm/s390_ext.h>
+ #include <asm/sysinfo.h>
+@@ -64,7 +65,6 @@ static void topology_work_fn(struct work
+ static struct tl_info *tl_info;
+ static struct core_info core_info;
+ static int machine_has_topology;
+-static int machine_has_topology_irq;
+ static struct timer_list topology_timer;
+ static void set_topology_timer(void);
+ static DECLARE_WORK(topology_work, topology_work_fn);
+@@ -81,7 +81,7 @@ cpumask_t cpu_coregroup_map(unsigned int
+
+ cpus_clear(mask);
+ if (!topology_enabled || !machine_has_topology)
+- return cpu_present_map;
++ return cpu_possible_map;
+ spin_lock_irqsave(&topology_lock, flags);
+ while (core) {
+ if (cpu_isset(cpu, core->mask)) {
+@@ -171,7 +171,7 @@ static void topology_update_polarization
+ int cpu;
+
+ mutex_lock(&smp_cpu_state_mutex);
+- for_each_present_cpu(cpu)
++ for_each_possible_cpu(cpu)
+ smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
+ mutex_unlock(&smp_cpu_state_mutex);
+ }
+@@ -202,7 +202,7 @@ int topology_set_cpu_management(int fc)
+ rc = ptf(PTF_HORIZONTAL);
+ if (rc)
+ return -EBUSY;
+- for_each_present_cpu(cpu)
++ for_each_possible_cpu(cpu)
+ smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
+ return rc;
+ }
+@@ -211,11 +211,11 @@ static void update_cpu_core_map(void)
+ {
+ int cpu;
+
+- for_each_present_cpu(cpu)
++ for_each_possible_cpu(cpu)
+ cpu_core_map[cpu] = cpu_coregroup_map(cpu);
+ }
+
+-void arch_update_cpu_topology(void)
++int arch_update_cpu_topology(void)
+ {
+ struct tl_info *info = tl_info;
+ struct sys_device *sysdev;
+@@ -224,7 +224,7 @@ void arch_update_cpu_topology(void)
+ if (!machine_has_topology) {
+ update_cpu_core_map();
+ topology_update_polarization_simple();
+- return;
++ return 0;
+ }
+ stsi(info, 15, 1, 2);
+ tl_to_cores(info);
+@@ -233,11 +233,12 @@ void arch_update_cpu_topology(void)
+ sysdev = get_cpu_sysdev(cpu);
+ kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
+ }
++ return 1;
+ }
+
+ static void topology_work_fn(struct work_struct *work)
+ {
+- arch_reinit_sched_domains();
++ rebuild_sched_domains();
+ }
+
+ void topology_schedule_update(void)
+@@ -260,11 +261,6 @@ static void set_topology_timer(void)
+ add_timer(&topology_timer);
+ }
+
+-static void topology_interrupt(__u16 code)
+-{
+- schedule_work(&topology_work);
+-}
+-
+ static int __init early_parse_topology(char *p)
+ {
+ if (strncmp(p, "on", 2))
+@@ -284,14 +280,7 @@ static int __init init_topology_update(v
+ goto out;
+ }
+ init_timer_deferrable(&topology_timer);
+- if (machine_has_topology_irq) {
+- rc = register_external_interrupt(0x2005, topology_interrupt);
+- if (rc)
+- goto out;
+- ctl_set_bit(0, 8);
+- }
+- else
+- set_topology_timer();
++ set_topology_timer();
+ out:
+ update_cpu_core_map();
+ return rc;
+@@ -312,9 +301,6 @@ void __init s390_init_cpu_topology(void)
+ return;
+ machine_has_topology = 1;
+
+- if (facility_bits & (1ULL << 51))
+- machine_has_topology_irq = 1;
+-
+ tl_info = alloc_bootmem_pages(PAGE_SIZE);
+ info = tl_info;
+ stsi(info, 15, 1, 2);
+@@ -338,5 +324,4 @@ void __init s390_init_cpu_topology(void)
+ return;
+ error:
+ machine_has_topology = 0;
+- machine_has_topology_irq = 0;
+ }
+--- a/include/linux/topology.h
++++ b/include/linux/topology.h
+@@ -49,7 +49,7 @@
+ for_each_online_node(node) \
+ if (nr_cpus_node(node))
+
+-void arch_update_cpu_topology(void);
++int arch_update_cpu_topology(void);
+
+ /* Conform to ACPI 2.0 SLIT distance definitions */
+ #define LOCAL_DISTANCE 10
+--- a/kernel/sched.c
++++ b/kernel/sched.c
+@@ -7640,8 +7640,14 @@ static struct sched_domain_attr *dattr_c
+ */
+ static cpumask_t fallback_doms;
+
+-void __attribute__((weak)) arch_update_cpu_topology(void)
++/*
++ * arch_update_cpu_topology lets virtualized architectures update the
++ * cpu core maps. It is supposed to return 1 if the topology changed
++ * or 0 if it stayed the same.
++ */
++int __attribute__((weak)) arch_update_cpu_topology(void)
+ {
++ return 0;
+ }
+
+ /*
+@@ -7735,17 +7741,21 @@ void partition_sched_domains(int ndoms_n
+ struct sched_domain_attr *dattr_new)
+ {
+ int i, j, n;
++ int top_changed;
+
+ mutex_lock(&sched_domains_mutex);
+
+ /* always unregister in case we don't destroy any domains */
+ unregister_sched_domain_sysctl();
+
++ /* Let architecture update cpu core mappings. */
++ top_changed = arch_update_cpu_topology();
++
+ n = doms_new ? ndoms_new : 0;
+
+ /* Destroy deleted domains */
+ for (i = 0; i < ndoms_cur; i++) {
+- for (j = 0; j < n; j++) {
++ for (j = 0; j < n && !top_changed; j++) {
+ if (cpus_equal(doms_cur[i], doms_new[j])
+ && dattrs_equal(dattr_cur, i, dattr_new, j))
+ goto match1;
+@@ -7765,7 +7775,7 @@ match1:
+
+ /* Build new domains */
+ for (i = 0; i < ndoms_new; i++) {
+- for (j = 0; j < ndoms_cur; j++) {
++ for (j = 0; j < ndoms_cur && !top_changed; j++) {
+ if (cpus_equal(doms_new[i], doms_cur[j])
+ && dattrs_equal(dattr_new, i, dattr_cur, j))
+ goto match2;
projects / people / teissler / ipfire-2.x.git / blobdiff