mm/zsmalloc: Convert to hotplug state machine

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-mm@kvack.org
Cc: Minchan Kim <minchan@kernel.org>
Cc: rt@linutronix.de
Cc: Nitin Gupta <ngupta@vflare.org>
Link: http://lkml.kernel.org/r/20161126231350.10321-11-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 4ebd1bc27f8d6260b9a035859c8be76d0ddfae3e..9f29dd9960881614175456f2dfe48e95547de74a 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -64,6 +64,7 @@ enum cpuhp_state {
        CPUHP_NET_IUCV_PREPARE,
        CPUHP_ARM_BL_PREPARE,
        CPUHP_TRACE_RB_PREPARE,
+       CPUHP_MM_ZS_PREPARE,
        CPUHP_TIMERS_DEAD,
        CPUHP_NOTF_ERR_INJ_PREPARE,
        CPUHP_MIPS_SOC_PREPARE,

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index b0bc023d25c539e05b5a874b65dcf575a136f271..9cc3c0b2c2c13fddddc6d5d52aca4f0b45fdc1ce 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1284,61 +1284,21 @@ out:
 
 #endif /* CONFIG_PGTABLE_MAPPING */
 
-static int zs_cpu_notifier(struct notifier_block *nb, unsigned long action,
-                               void *pcpu)
+static int zs_cpu_prepare(unsigned int cpu)
 {
-       int ret, cpu = (long)pcpu;
        struct mapping_area *area;
 
-       switch (action) {
-       case CPU_UP_PREPARE:
-               area = &per_cpu(zs_map_area, cpu);
-               ret = __zs_cpu_up(area);
-               if (ret)
-                       return notifier_from_errno(ret);
-               break;
-       case CPU_DEAD:
-       case CPU_UP_CANCELED:
-               area = &per_cpu(zs_map_area, cpu);
-               __zs_cpu_down(area);
-               break;
-       }
-
-       return NOTIFY_OK;
+       area = &per_cpu(zs_map_area, cpu);
+       return __zs_cpu_up(area);
 }
 
-static struct notifier_block zs_cpu_nb = {
-       .notifier_call = zs_cpu_notifier
-};
-
-static int zs_register_cpu_notifier(void)
+static int zs_cpu_dead(unsigned int cpu)
 {
-       int cpu, uninitialized_var(ret);
-
-       cpu_notifier_register_begin();
-
-       __register_cpu_notifier(&zs_cpu_nb);
-       for_each_online_cpu(cpu) {
-               ret = zs_cpu_notifier(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
-               if (notifier_to_errno(ret))
-                       break;
-       }
-
-       cpu_notifier_register_done();
-       return notifier_to_errno(ret);
-}
-
-static void zs_unregister_cpu_notifier(void)
-{
-       int cpu;
-
-       cpu_notifier_register_begin();
-
-       for_each_online_cpu(cpu)
-               zs_cpu_notifier(NULL, CPU_DEAD, (void *)(long)cpu);
-       __unregister_cpu_notifier(&zs_cpu_nb);
+       struct mapping_area *area;
 
-       cpu_notifier_register_done();
+       area = &per_cpu(zs_map_area, cpu);
+       __zs_cpu_down(area);
+       return 0;
 }
 
 static void __init init_zs_size_classes(void)
@@ -2534,10 +2494,10 @@ static int __init zs_init(void)
        if (ret)
                goto out;
 
-       ret = zs_register_cpu_notifier();
-
+       ret = cpuhp_setup_state(CPUHP_MM_ZS_PREPARE, "mm/zsmalloc:prepare",
+                               zs_cpu_prepare, zs_cpu_dead);
        if (ret)
-               goto notifier_fail;
+               goto hp_setup_fail;
 
        init_zs_size_classes();
 
@@ -2549,8 +2509,7 @@ static int __init zs_init(void)
 
        return 0;
 
-notifier_fail:
-       zs_unregister_cpu_notifier();
+hp_setup_fail:
        zsmalloc_unmount();
 out:
        return ret;
@@ -2562,7 +2521,7 @@ static void __exit zs_exit(void)
        zpool_unregister_driver(&zs_zpool_driver);
 #endif
        zsmalloc_unmount();
-       zs_unregister_cpu_notifier();
+       cpuhp_remove_state(CPUHP_MM_ZS_PREPARE);
 
        zs_stat_exit();
 }