[S390] topology: fix topology on z10 machines

Make sure that all cpus in a book on a z10 appear as book siblings
and not as core siblings. This fixes some performance regressions that
appeared after the book scheduling domain got introduced.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 77b8942..fdb5b8c 100644 (file)
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -68,8 +68,10 @@ static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
        return mask;
 }
 
-static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
-                            struct mask_info *book, struct mask_info *core)
+static struct mask_info *add_cpus_to_mask(struct topology_cpu *tl_cpu,
+                                         struct mask_info *book,
+                                         struct mask_info *core,
+                                         int z10)
 {
        unsigned int cpu;
 
@@ -88,10 +90,16 @@ static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
                        cpu_book_id[lcpu] = book->id;
 #endif
                        cpumask_set_cpu(lcpu, &core->mask);
-                       cpu_core_id[lcpu] = core->id;
+                       if (z10) {
+                               cpu_core_id[lcpu] = rcpu;
+                               core = core->next;
+                       } else {
+                               cpu_core_id[lcpu] = core->id;
+                       }
                        smp_cpu_polarization[lcpu] = tl_cpu->pp;
                }
        }
+       return core;
 }
 
 static void clear_masks(void)
@@ -123,18 +131,41 @@ static void tl_to_cores(struct sysinfo_15_1_x *info)
 {
 #ifdef CONFIG_SCHED_BOOK
        struct mask_info *book = &book_info;
+       struct cpuid cpu_id;
 #else
        struct mask_info *book = NULL;
 #endif
        struct mask_info *core = &core_info;
        union topology_entry *tle, *end;
+       int z10 = 0;
 
-
+#ifdef CONFIG_SCHED_BOOK
+       get_cpu_id(&cpu_id);
+       z10 = cpu_id.machine == 0x2097 || cpu_id.machine == 0x2098;
+#endif
        spin_lock_irq(&topology_lock);
        clear_masks();
        tle = info->tle;
        end = (union topology_entry *)((unsigned long)info + info->length);
        while (tle < end) {
+#ifdef CONFIG_SCHED_BOOK
+               if (z10) {
+                       switch (tle->nl) {
+                       case 1:
+                               book = book->next;
+                               book->id = tle->container.id;
+                               break;
+                       case 0:
+                               core = add_cpus_to_mask(&tle->cpu, book, core, z10);
+                               break;
+                       default:
+                               clear_masks();
+                               goto out;
+                       }
+                       tle = next_tle(tle);
+                       continue;
+               }
+#endif
                switch (tle->nl) {
 #ifdef CONFIG_SCHED_BOOK
                case 2:
@@ -147,7 +178,7 @@ static void tl_to_cores(struct sysinfo_15_1_x *info)
                        core->id = tle->container.id;
                        break;
                case 0:
-                       add_cpus_to_mask(&tle->cpu, book, core);
+                       add_cpus_to_mask(&tle->cpu, book, core, z10);
                        break;
                default:
                        clear_masks();
@@ -328,8 +359,8 @@ void __init s390_init_cpu_topology(void)
        for (i = 0; i < TOPOLOGY_NR_MAG; i++)
                printk(" %d", info->mag[i]);
        printk(" / %d\n", info->mnest);
-       alloc_masks(info, &core_info, 2);
+       alloc_masks(info, &core_info, 1);
 #ifdef CONFIG_SCHED_BOOK
-       alloc_masks(info, &book_info, 3);
+       alloc_masks(info, &book_info, 2);
 #endif
 }