From 50a038d5cee6f59d6ead581c0472d89de50bafa1 Mon Sep 17 00:00:00 2001 From: Anna-Maria Gleixner Date: Sun, 27 Nov 2016 00:13:46 +0100 Subject: [PATCH] zram: Convert to hotplug state machine Install the callbacks via the state machine with multi instance support and let the core invoke the callbacks on the already online CPUs. [bigeasy: wire up the multi instance stuff] [B--B: fixed wrong spacing and newlines] Signed-off-by: Anna-Maria Gleixner Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Sergey Senozhatsky Cc: Minchan Kim Cc: rt@linutronix.de Cc: Nitin Gupta Link: http://lkml.kernel.org/r/20161126231350.10321-19-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner Signed-off-by: Marco Zanin Signed-off-by: snnbyyds Signed-off-by: Sorayukii --- drivers/block/zram/zcomp.c | 76 ++++++++++++----------------------- drivers/block/zram/zcomp.h | 5 ++- drivers/block/zram/zram_drv.c | 9 +++++ include/linux/cpuhotplug.h | 1 + 4 files changed, 38 insertions(+), 53 deletions(-) diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index c084a7f9763d..a1fa20f5e08c 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -163,82 +163,56 @@ int zcomp_decompress(struct zcomp_strm *zstrm, dst, &dst_len); } -static int __zcomp_cpu_notifier(struct zcomp *comp, - unsigned long action, unsigned long cpu) +int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node) { + struct zcomp *comp = hlist_entry(node, struct zcomp, node); struct zcomp_strm *zstrm; - switch (action) { - case CPU_UP_PREPARE: - if (WARN_ON(*per_cpu_ptr(comp->stream, cpu))) - break; - zstrm = zcomp_strm_alloc(comp); - if (IS_ERR_OR_NULL(zstrm)) { - pr_err("Can't allocate a compression stream\n"); - return NOTIFY_BAD; - } - *per_cpu_ptr(comp->stream, cpu) = zstrm; - break; - case CPU_DEAD: - case CPU_UP_CANCELED: - zstrm = *per_cpu_ptr(comp->stream, cpu); - if (!IS_ERR_OR_NULL(zstrm)) - zcomp_strm_free(zstrm); - *per_cpu_ptr(comp->stream, cpu) = NULL; - break; - default: - break; + if (WARN_ON(*per_cpu_ptr(comp->stream, cpu))) + return 0; + + zstrm = zcomp_strm_alloc(comp); + if (IS_ERR_OR_NULL(zstrm)) { + pr_err("Can't allocate a compression stream\n"); + return -ENOMEM; } - return NOTIFY_OK; + *per_cpu_ptr(comp->stream, cpu) = zstrm; + return 0; } -static int zcomp_cpu_notifier(struct notifier_block *nb, - unsigned long action, void *pcpu) +int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node) { - unsigned long cpu = (unsigned long)pcpu; - struct zcomp *comp = container_of(nb, typeof(*comp), notifier); + struct zcomp *comp = hlist_entry(node, struct zcomp, node); + struct zcomp_strm *zstrm; - return __zcomp_cpu_notifier(comp, action, cpu); + zstrm = *per_cpu_ptr(comp->stream, cpu); + if (!IS_ERR_OR_NULL(zstrm)) + zcomp_strm_free(zstrm); + *per_cpu_ptr(comp->stream, cpu) = NULL; + return 0; } static int zcomp_init(struct zcomp *comp) { - unsigned long cpu; int ret; - comp->notifier.notifier_call = zcomp_cpu_notifier; - comp->stream = alloc_percpu(struct zcomp_strm *); if (!comp->stream) return -ENOMEM; - cpu_notifier_register_begin(); - for_each_online_cpu(cpu) { - ret = __zcomp_cpu_notifier(comp, CPU_UP_PREPARE, cpu); - if (ret == NOTIFY_BAD) - goto cleanup; - } - __register_cpu_notifier(&comp->notifier); - cpu_notifier_register_done(); + ret = cpuhp_state_add_instance(CPUHP_ZCOMP_PREPARE, &comp->node); + if (ret < 0) + goto cleanup; return 0; cleanup: - for_each_online_cpu(cpu) - __zcomp_cpu_notifier(comp, CPU_UP_CANCELED, cpu); - cpu_notifier_register_done(); - return -ENOMEM; + free_percpu(comp->stream); + return ret; } void zcomp_destroy(struct zcomp *comp) { - unsigned long cpu; - - cpu_notifier_register_begin(); - for_each_online_cpu(cpu) - __zcomp_cpu_notifier(comp, CPU_UP_CANCELED, cpu); - __unregister_cpu_notifier(&comp->notifier); - cpu_notifier_register_done(); - + cpuhp_state_remove_instance(CPUHP_ZCOMP_PREPARE, &comp->node); free_percpu(comp->stream); kfree(comp); } diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h index 478cac2ed465..41c1002a7d7d 100644 --- a/drivers/block/zram/zcomp.h +++ b/drivers/block/zram/zcomp.h @@ -19,11 +19,12 @@ struct zcomp_strm { /* dynamic per-device compression frontend */ struct zcomp { struct zcomp_strm * __percpu *stream; - struct notifier_block notifier; - const char *name; + struct hlist_node node; }; +int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node); +int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node); ssize_t zcomp_available_show(const char *comp, char *buf); bool zcomp_available_algorithm(const char *comp); diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 571a73d70f83..b6cb2435b234 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -32,6 +32,7 @@ #include #include #include +#include #include "zram_drv.h" @@ -2239,15 +2240,22 @@ static void destroy_devices(void) zram_debugfs_destroy(); idr_destroy(&zram_index_idr); unregister_blkdev(zram_major, "zram"); + cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE); } static int __init zram_init(void) { int ret; + ret = cpuhp_setup_state_multi(CPUHP_ZCOMP_PREPARE, "block/zram:prepare", + zcomp_cpu_up_prepare, zcomp_cpu_dead); + if (ret < 0) + return ret; + ret = class_register(&zram_control_class); if (ret) { pr_err("Unable to register zram-control class\n"); + cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE); return ret; } @@ -2256,6 +2264,7 @@ static int __init zram_init(void) if (zram_major <= 0) { pr_err("Unable to get major number\n"); class_unregister(&zram_control_class); + cpuhp_remove_multi_state(CPUHP_ZCOMP_PREPARE); return -EBUSY; } diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index bb0cebafc846..5df2d2158113 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -53,6 +53,7 @@ enum cpuhp_state { CPUHP_BLK_MQ_PREPARE, CPUHP_TOPOLOGY_PREPARE, CPUHP_TIMERS_PREPARE, + CPUHP_ZCOMP_PREPARE, CPUHP_NOTF_ERR_INJ_PREPARE, CPUHP_MIPS_SOC_PREPARE, CPUHP_BRINGUP_CPU,