From 6731d4f12315aed5f7eefc52dac30428e382d7d0 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 23 Aug 2016 14:53:19 +0200 Subject: slab: Convert to hotplug state machine Install the callbacks via the state machine. Signed-off-by: Richard Weinberger Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Sebastian Andrzej Siewior Cc: Peter Zijlstra Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: rt@linutronix.de Cc: David Rientjes Cc: Joonsoo Kim Cc: Andrew Morton Cc: Christoph Lameter Link: http://lkml.kernel.org/r/20160823125319.abeapfjapf2kfezp@linutronix.de Signed-off-by: Thomas Gleixner --- mm/slab.c | 114 ++++++++++++++++++++++++++++---------------------------------- 1 file changed, 51 insertions(+), 63 deletions(-) (limited to 'mm') diff --git a/mm/slab.c b/mm/slab.c index b67271024135..090fb26b3a39 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -886,6 +886,7 @@ static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp) return 0; } +#if (defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)) || defined(CONFIG_SMP) /* * Allocates and initializes node for a node on each slab cache, used for * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node @@ -908,6 +909,7 @@ static int init_cache_node_node(int node) return 0; } +#endif static int setup_kmem_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp, bool force_change) @@ -975,6 +977,8 @@ fail: return ret; } +#ifdef CONFIG_SMP + static void cpuup_canceled(long cpu) { struct kmem_cache *cachep; @@ -1075,65 +1079,54 @@ bad: return -ENOMEM; } -static int cpuup_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) +int slab_prepare_cpu(unsigned int cpu) { - long cpu = (long)hcpu; - int err = 0; + int err; - switch (action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - mutex_lock(&slab_mutex); - err = cpuup_prepare(cpu); - mutex_unlock(&slab_mutex); - break; - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - start_cpu_timer(cpu); - break; -#ifdef CONFIG_HOTPLUG_CPU - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - /* - * Shutdown cache reaper. Note that the slab_mutex is - * held so that if cache_reap() is invoked it cannot do - * anything expensive but will only modify reap_work - * and reschedule the timer. - */ - cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); - /* Now the cache_reaper is guaranteed to be not running. */ - per_cpu(slab_reap_work, cpu).work.func = NULL; - break; - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - start_cpu_timer(cpu); - break; - case CPU_DEAD: - case CPU_DEAD_FROZEN: - /* - * Even if all the cpus of a node are down, we don't free the - * kmem_cache_node of any cache. This to avoid a race between - * cpu_down, and a kmalloc allocation from another cpu for - * memory from the node of the cpu going down. The node - * structure is usually allocated from kmem_cache_create() and - * gets destroyed at kmem_cache_destroy(). - */ - /* fall through */ + mutex_lock(&slab_mutex); + err = cpuup_prepare(cpu); + mutex_unlock(&slab_mutex); + return err; +} + +/* + * This is called for a failed online attempt and for a successful + * offline. + * + * Even if all the cpus of a node are down, we don't free the + * kmem_list3 of any cache. This to avoid a race between cpu_down, and + * a kmalloc allocation from another cpu for memory from the node of + * the cpu going down. The list3 structure is usually allocated from + * kmem_cache_create() and gets destroyed at kmem_cache_destroy(). + */ +int slab_dead_cpu(unsigned int cpu) +{ + mutex_lock(&slab_mutex); + cpuup_canceled(cpu); + mutex_unlock(&slab_mutex); + return 0; +} #endif - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - mutex_lock(&slab_mutex); - cpuup_canceled(cpu); - mutex_unlock(&slab_mutex); - break; - } - return notifier_from_errno(err); + +static int slab_online_cpu(unsigned int cpu) +{ + start_cpu_timer(cpu); + return 0; } -static struct notifier_block cpucache_notifier = { - &cpuup_callback, NULL, 0 -}; +static int slab_offline_cpu(unsigned int cpu) +{ + /* + * Shutdown cache reaper. Note that the slab_mutex is held so + * that if cache_reap() is invoked it cannot do anything + * expensive but will only modify reap_work and reschedule the + * timer. + */ + cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); + /* Now the cache_reaper is guaranteed to be not running. */ + per_cpu(slab_reap_work, cpu).work.func = NULL; + return 0; +} #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) /* @@ -1336,12 +1329,6 @@ void __init kmem_cache_init_late(void) /* Done! */ slab_state = FULL; - /* - * Register a cpu startup notifier callback that initializes - * cpu_cache_get for all new cpus - */ - register_cpu_notifier(&cpucache_notifier); - #ifdef CONFIG_NUMA /* * Register a memory hotplug callback that initializes and frees @@ -1358,13 +1345,14 @@ void __init kmem_cache_init_late(void) static int __init cpucache_init(void) { - int cpu; + int ret; /* * Register the timers that return unneeded pages to the page allocator */ - for_each_online_cpu(cpu) - start_cpu_timer(cpu); + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SLAB online", + slab_online_cpu, slab_offline_cpu); + WARN_ON(ret < 0); /* Done! */ slab_state = FULL; -- cgit 1.4.1 From a96a87bf949d249039cdf532bb5f5d06622cc5e2 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 18 Aug 2016 14:57:19 +0200 Subject: slub: Convert to hotplug state machine Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior Cc: Andrew Morton Cc: Peter Zijlstra Cc: Pekka Enberg Cc: linux-mm@kvack.org Cc: rt@linutronix.de Cc: David Rientjes Cc: Christoph Lameter Cc: Joonsoo Kim Link: http://lkml.kernel.org/r/20160818125731.27256-5-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- include/linux/cpuhotplug.h | 1 + mm/slub.c | 65 +++++++++++++++------------------------------- 2 files changed, 22 insertions(+), 44 deletions(-) (limited to 'mm') diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index c2cf14953abc..82ee32107dff 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -15,6 +15,7 @@ enum cpuhp_state { CPUHP_X86_HPET_DEAD, CPUHP_X86_APB_DEAD, CPUHP_VIRT_NET_DEAD, + CPUHP_SLUB_DEAD, CPUHP_WORKQUEUE_PREP, CPUHP_POWER_NUMA_PREPARE, CPUHP_HRTIMERS_PREPARE, diff --git a/mm/slub.c b/mm/slub.c index 9adae58462f8..2b3e740609e9 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -194,10 +194,6 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s) #define __OBJECT_POISON 0x80000000UL /* Poison object */ #define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */ -#ifdef CONFIG_SMP -static struct notifier_block slab_notifier; -#endif - /* * Tracking user of a slab. */ @@ -2304,6 +2300,25 @@ static void flush_all(struct kmem_cache *s) on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC); } +/* + * Use the cpu notifier to insure that the cpu slabs are flushed when + * necessary. + */ +static int slub_cpu_dead(unsigned int cpu) +{ + struct kmem_cache *s; + unsigned long flags; + + mutex_lock(&slab_mutex); + list_for_each_entry(s, &slab_caches, list) { + local_irq_save(flags); + __flush_cpu_slab(s, cpu); + local_irq_restore(flags); + } + mutex_unlock(&slab_mutex); + return 0; +} + /* * Check if the objects in a per cpu structure fit numa * locality expectations. @@ -4144,9 +4159,8 @@ void __init kmem_cache_init(void) /* Setup random freelists for each cache */ init_freelist_randomization(); -#ifdef CONFIG_SMP - register_cpu_notifier(&slab_notifier); -#endif + cpuhp_setup_state_nocalls(CPUHP_SLUB_DEAD, "slub:dead", NULL, + slub_cpu_dead); pr_info("SLUB: HWalign=%d, Order=%d-%d, MinObjects=%d, CPUs=%d, Nodes=%d\n", cache_line_size(), @@ -4210,43 +4224,6 @@ int __kmem_cache_create(struct kmem_cache *s, unsigned long flags) return err; } -#ifdef CONFIG_SMP -/* - * Use the cpu notifier to insure that the cpu slabs are flushed when - * necessary. - */ -static int slab_cpuup_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) -{ - long cpu = (long)hcpu; - struct kmem_cache *s; - unsigned long flags; - - switch (action) { - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - case CPU_DEAD: - case CPU_DEAD_FROZEN: - mutex_lock(&slab_mutex); - list_for_each_entry(s, &slab_caches, list) { - local_irq_save(flags); - __flush_cpu_slab(s, cpu); - local_irq_restore(flags); - } - mutex_unlock(&slab_mutex); - break; - default: - break; - } - return NOTIFY_OK; -} - -static struct notifier_block slab_notifier = { - .notifier_call = slab_cpuup_callback -}; - -#endif - void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller) { struct kmem_cache *s; -- cgit 1.4.1 From 1d7ac6aec947d222042b6d22b3cec109db4fd19e Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 18 Aug 2016 14:57:20 +0200 Subject: mm/writeback: 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: Jens Axboe Cc: linux-mm@kvack.org Cc: rt@linutronix.de Cc: Tejun Heo Link: http://lkml.kernel.org/r/20160818125731.27256-6-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- include/linux/cpuhotplug.h | 1 + mm/page-writeback.c | 26 +++++++------------------- 2 files changed, 8 insertions(+), 19 deletions(-) (limited to 'mm') diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 82ee32107dff..854e59a426d4 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -16,6 +16,7 @@ enum cpuhp_state { CPUHP_X86_APB_DEAD, CPUHP_VIRT_NET_DEAD, CPUHP_SLUB_DEAD, + CPUHP_MM_WRITEBACK_DEAD, CPUHP_WORKQUEUE_PREP, CPUHP_POWER_NUMA_PREPARE, CPUHP_HRTIMERS_PREPARE, diff --git a/mm/page-writeback.c b/mm/page-writeback.c index f4cd7d8005c9..28d6f36a2d79 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2080,26 +2080,12 @@ void writeback_set_ratelimit(void) ratelimit_pages = 16; } -static int -ratelimit_handler(struct notifier_block *self, unsigned long action, - void *hcpu) +static int page_writeback_cpu_online(unsigned int cpu) { - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_ONLINE: - case CPU_DEAD: - writeback_set_ratelimit(); - return NOTIFY_OK; - default: - return NOTIFY_DONE; - } + writeback_set_ratelimit(); + return 0; } -static struct notifier_block ratelimit_nb = { - .notifier_call = ratelimit_handler, - .next = NULL, -}; - /* * Called early on to tune the page writeback dirty limits. * @@ -2122,8 +2108,10 @@ void __init page_writeback_init(void) { BUG_ON(wb_domain_init(&global_wb_domain, GFP_KERNEL)); - writeback_set_ratelimit(); - register_cpu_notifier(&ratelimit_nb); + cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mm/writeback:online", + page_writeback_cpu_online, NULL); + cpuhp_setup_state(CPUHP_MM_WRITEBACK_DEAD, "mm/writeback:dead", NULL, + page_writeback_cpu_online); } /** -- cgit 1.4.1