staging/lustre/libcfs: Convert to hotplug state machine

Install the callbacks via the state machine. No functional change.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: devel@driverdev.osuosl.org
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: rt@linutronix.de
Cc: lustre-devel@lists.lustre.org
Link: http://lkml.kernel.org/r/20161202110027.htzzeervzkoc4muv@linutronix.de
Link: http://lkml.kernel.org/r/20161221192111.922872524@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c b/drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c
index 6b9cf06e8df2b91824294b4bc9ee2e5870191ff4..427e2198bb9e85b8a11693fd7fb1495f2799aa7e 100644 (file)
--- a/drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c
+++ b/drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c
@@ -967,48 +967,38 @@ cfs_cpt_table_create_pattern(char *pattern)
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
-static int
-cfs_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
-{
-       unsigned int cpu = (unsigned long)hcpu;
-       bool warn;
-
-       switch (action) {
-       case CPU_DEAD:
-       case CPU_DEAD_FROZEN:
-       case CPU_ONLINE:
-       case CPU_ONLINE_FROZEN:
-               spin_lock(&cpt_data.cpt_lock);
-               cpt_data.cpt_version++;
-               spin_unlock(&cpt_data.cpt_lock);
-               /* Fall through */
-       default:
-               if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) {
-                       CDEBUG(D_INFO, "CPU changed [cpu %u action %lx]\n",
-                              cpu, action);
-                       break;
-               }
+static enum cpuhp_state lustre_cpu_online;
 
-               mutex_lock(&cpt_data.cpt_mutex);
-               /* if all HTs in a core are offline, it may break affinity */
-               cpumask_copy(cpt_data.cpt_cpumask,
-                            topology_sibling_cpumask(cpu));
-               warn = cpumask_any_and(cpt_data.cpt_cpumask,
-                                      cpu_online_mask) >= nr_cpu_ids;
-               mutex_unlock(&cpt_data.cpt_mutex);
-               CDEBUG(warn ? D_WARNING : D_INFO,
-                      "Lustre: can't support CPU plug-out well now, performance and stability could be impacted [CPU %u action: %lx]\n",
-                      cpu, action);
-       }
+static void cfs_cpu_incr_cpt_version(void)
+{
+       spin_lock(&cpt_data.cpt_lock);
+       cpt_data.cpt_version++;
+       spin_unlock(&cpt_data.cpt_lock);
+}
 
-       return NOTIFY_OK;
+static int cfs_cpu_online(unsigned int cpu)
+{
+       cfs_cpu_incr_cpt_version();
+       return 0;
 }
 
-static struct notifier_block cfs_cpu_notifier = {
-       .notifier_call  = cfs_cpu_notify,
-       .priority       = 0
-};
+static int cfs_cpu_dead(unsigned int cpu)
+{
+       bool warn;
+
+       cfs_cpu_incr_cpt_version();
 
+       mutex_lock(&cpt_data.cpt_mutex);
+       /* if all HTs in a core are offline, it may break affinity */
+       cpumask_copy(cpt_data.cpt_cpumask, topology_sibling_cpumask(cpu));
+       warn = cpumask_any_and(cpt_data.cpt_cpumask,
+                              cpu_online_mask) >= nr_cpu_ids;
+       mutex_unlock(&cpt_data.cpt_mutex);
+       CDEBUG(warn ? D_WARNING : D_INFO,
+              "Lustre: can't support CPU plug-out well now, performance and stability could be impacted [CPU %u]\n",
+              cpu);
+       return 0;
+}
 #endif
 
 void
@@ -1018,7 +1008,9 @@ cfs_cpu_fini(void)
                cfs_cpt_table_free(cfs_cpt_table);
 
 #ifdef CONFIG_HOTPLUG_CPU
-       unregister_hotcpu_notifier(&cfs_cpu_notifier);
+       if (lustre_cpu_online > 0)
+               cpuhp_remove_state_nocalls(lustre_cpu_online);
+       cpuhp_remove_state_nocalls(CPUHP_LUSTRE_CFS_DEAD);
 #endif
        if (cpt_data.cpt_cpumask)
                LIBCFS_FREE(cpt_data.cpt_cpumask, cpumask_size());
@@ -1027,6 +1019,8 @@ cfs_cpu_fini(void)
 int
 cfs_cpu_init(void)
 {
+       int ret = 0;
+
        LASSERT(!cfs_cpt_table);
 
        memset(&cpt_data, 0, sizeof(cpt_data));
@@ -1041,8 +1035,19 @@ cfs_cpu_init(void)
        mutex_init(&cpt_data.cpt_mutex);
 
 #ifdef CONFIG_HOTPLUG_CPU
-       register_hotcpu_notifier(&cfs_cpu_notifier);
+       ret = cpuhp_setup_state_nocalls(CPUHP_LUSTRE_CFS_DEAD,
+                                       "staging/lustre/cfe:dead", NULL,
+                                       cfs_cpu_dead);
+       if (ret < 0)
+               goto failed;
+       ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+                                       "staging/lustre/cfe:online",
+                                       cfs_cpu_online, NULL);
+       if (ret < 0)
+               goto failed;
+       lustre_cpu_online = ret;
 #endif
+       ret = -EINVAL;
 
        if (*cpu_pattern) {
                cfs_cpt_table = cfs_cpt_table_create_pattern(cpu_pattern);
@@ -1075,7 +1080,7 @@ cfs_cpu_init(void)
 
  failed:
        cfs_cpu_fini();
-       return -1;
+       return ret;
 }
 
 #endif

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index fc4587c05dd3bcddc671c604303222f63fafa2ee..175d276ac3359177bf14a6f84f45f89a7f8d3f25 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -41,6 +41,7 @@ enum cpuhp_state {
        CPUHP_NET_DEV_DEAD,
        CPUHP_PCI_XGENE_DEAD,
        CPUHP_IOMMU_INTEL_DEAD,
+       CPUHP_LUSTRE_CFS_DEAD,
        CPUHP_SCSI_BNX2FC_DEAD,
        CPUHP_SCSI_BNX2I_DEAD,
        CPUHP_WORKQUEUE_PREP,