From 29c6d1bbd7a2cd88a197ea7cef171f616e198526 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 18 Aug 2016 14:57:24 +0200 Subject: [PATCH] md/raid5: 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 Cc: Peter Zijlstra Cc: Neil Brown Cc: linux-raid@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160818125731.27256-10-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- drivers/md/raid5.c | 84 +++++++++++++------------------------- drivers/md/raid5.h | 4 +- include/linux/cpuhotplug.h | 1 + 3 files changed, 31 insertions(+), 58 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 8912407a4dd0..aae8064fd9e6 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6330,22 +6330,20 @@ static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu return 0; } +static int raid456_cpu_dead(unsigned int cpu, struct hlist_node *node) +{ + struct r5conf *conf = hlist_entry_safe(node, struct r5conf, node); + + free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu)); + return 0; +} + static void raid5_free_percpu(struct r5conf *conf) { - unsigned long cpu; - if (!conf->percpu) return; -#ifdef CONFIG_HOTPLUG_CPU - unregister_cpu_notifier(&conf->cpu_notify); -#endif - - get_online_cpus(); - for_each_possible_cpu(cpu) - free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu)); - put_online_cpus(); - + cpuhp_state_remove_instance(CPUHP_MD_RAID5_PREPARE, &conf->node); free_percpu(conf->percpu); } @@ -6364,64 +6362,28 @@ static void free_conf(struct r5conf *conf) kfree(conf); } -#ifdef CONFIG_HOTPLUG_CPU -static int raid456_cpu_notify(struct notifier_block *nfb, unsigned long action, - void *hcpu) +static int raid456_cpu_up_prepare(unsigned int cpu, struct hlist_node *node) { - struct r5conf *conf = container_of(nfb, struct r5conf, cpu_notify); - long cpu = (long)hcpu; + struct r5conf *conf = hlist_entry_safe(node, struct r5conf, node); struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu); - switch (action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - if (alloc_scratch_buffer(conf, percpu)) { - pr_err("%s: failed memory allocation for cpu%ld\n", - __func__, cpu); - return notifier_from_errno(-ENOMEM); - } - break; - case CPU_DEAD: - case CPU_DEAD_FROZEN: - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu)); - break; - default: - break; + if (alloc_scratch_buffer(conf, percpu)) { + pr_err("%s: failed memory allocation for cpu%u\n", + __func__, cpu); + return -ENOMEM; } - return NOTIFY_OK; + return 0; } -#endif static int raid5_alloc_percpu(struct r5conf *conf) { - unsigned long cpu; int err = 0; conf->percpu = alloc_percpu(struct raid5_percpu); if (!conf->percpu) return -ENOMEM; -#ifdef CONFIG_HOTPLUG_CPU - conf->cpu_notify.notifier_call = raid456_cpu_notify; - conf->cpu_notify.priority = 0; - err = register_cpu_notifier(&conf->cpu_notify); - if (err) - return err; -#endif - - get_online_cpus(); - for_each_present_cpu(cpu) { - err = alloc_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu)); - if (err) { - pr_err("%s: failed memory allocation for cpu%ld\n", - __func__, cpu); - break; - } - } - put_online_cpus(); - + err = cpuhp_state_add_instance(CPUHP_MD_RAID5_PREPARE, &conf->node); if (!err) { conf->scribble_disks = max(conf->raid_disks, conf->previous_raid_disks); @@ -7953,10 +7915,21 @@ static struct md_personality raid4_personality = static int __init raid5_init(void) { + int ret; + raid5_wq = alloc_workqueue("raid5wq", WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE|WQ_SYSFS, 0); if (!raid5_wq) return -ENOMEM; + + ret = cpuhp_setup_state_multi(CPUHP_MD_RAID5_PREPARE, + "md/raid5:prepare", + raid456_cpu_up_prepare, + raid456_cpu_dead); + if (ret) { + destroy_workqueue(raid5_wq); + return ret; + } register_md_personality(&raid6_personality); register_md_personality(&raid5_personality); register_md_personality(&raid4_personality); @@ -7968,6 +7941,7 @@ static void raid5_exit(void) unregister_md_personality(&raid6_personality); unregister_md_personality(&raid5_personality); unregister_md_personality(&raid4_personality); + cpuhp_remove_multi_state(CPUHP_MD_RAID5_PREPARE); destroy_workqueue(raid5_wq); } diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 517d4b68a1be..57ec49f0839e 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -512,9 +512,7 @@ struct r5conf { } __percpu *percpu; int scribble_disks; int scribble_sectors; -#ifdef CONFIG_HOTPLUG_CPU - struct notifier_block cpu_notify; -#endif + struct hlist_node node; /* * Free stripes pool diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 332b39c21d2e..4066c74bb73c 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -27,6 +27,7 @@ enum cpuhp_state { CPUHP_SMPCFD_PREPARE, CPUHP_RELAY_PREPARE, CPUHP_SLAB_PREPARE, + CPUHP_MD_RAID5_PREPARE, CPUHP_RCUTREE_PREP, CPUHP_NOTIFY_PREPARE, CPUHP_TIMERS_DEAD,