From 58d4f14fc30ac26288cfed74d7e566921c22cf59 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 27 May 2020 07:24:14 +0200 Subject: [PATCH] block: always use a percpu variable for disk stats percpu variables have a perfectly fine working stub implementation for UP kernels, so use that. Signed-off-by: Christoph Hellwig Reviewed-by: Konstantin Khlebnikov Signed-off-by: Jens Axboe --- block/blk.h | 2 +- block/genhd.c | 12 +++-------- block/partitions/core.c | 5 +++-- include/linux/genhd.h | 13 ----------- include/linux/part_stat.h | 55 ++++++++++------------------------------------- 5 files changed, 18 insertions(+), 69 deletions(-) diff --git a/block/blk.h b/block/blk.h index bdf5e94467aa..0ecba2ab383d 100644 --- a/block/blk.h +++ b/block/blk.h @@ -378,7 +378,7 @@ static inline void hd_struct_put(struct hd_struct *part) static inline void hd_free_part(struct hd_struct *part) { - free_part_stats(part); + free_percpu(part->dkstats); kfree(part->info); percpu_ref_exit(&part->ref); } diff --git a/block/genhd.c b/block/genhd.c index 094ed9096496..3e7df0a3e6bb 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -92,7 +92,6 @@ const char *bdevname(struct block_device *bdev, char *buf) } EXPORT_SYMBOL(bdevname); -#ifdef CONFIG_SMP static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat) { int cpu; @@ -112,12 +111,6 @@ static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat) stat->io_ticks += ptr->io_ticks; } } -#else /* CONFIG_SMP */ -static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat) -{ - memcpy(stat, &part->dkstats, sizeof(struct disk_stats)); -} -#endif /* CONFIG_SMP */ static unsigned int part_in_flight(struct request_queue *q, struct hd_struct *part) @@ -1688,14 +1681,15 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id); if (disk) { - if (!init_part_stats(&disk->part0)) { + disk->part0.dkstats = alloc_percpu(struct disk_stats); + if (!disk->part0.dkstats) { kfree(disk); return NULL; } init_rwsem(&disk->lookup_sem); disk->node_id = node_id; if (disk_expand_part_tbl(disk, 0)) { - free_part_stats(&disk->part0); + free_percpu(disk->part0.dkstats); kfree(disk); return NULL; } diff --git a/block/partitions/core.c b/block/partitions/core.c index 297004fd2264..78951e33b2d7 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -387,7 +387,8 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno, if (!p) return ERR_PTR(-EBUSY); - if (!init_part_stats(p)) { + p->dkstats = alloc_percpu(struct disk_stats); + if (!p->dkstats) { err = -ENOMEM; goto out_free; } @@ -468,7 +469,7 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno, out_free_info: kfree(p->info); out_free_stats: - free_part_stats(p); + free_percpu(p->dkstats); out_free: kfree(p); return ERR_PTR(err); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index a9384449465a..f0d6d77309a5 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -39,15 +39,6 @@ extern struct class block_class; #include #include -struct disk_stats { - u64 nsecs[NR_STAT_GROUPS]; - unsigned long sectors[NR_STAT_GROUPS]; - unsigned long ios[NR_STAT_GROUPS]; - unsigned long merges[NR_STAT_GROUPS]; - unsigned long io_ticks; - local_t in_flight[2]; -}; - #define PARTITION_META_INFO_VOLNAMELTH 64 /* * Enough for the string representation of any kind of UUID plus NULL. @@ -72,11 +63,7 @@ struct hd_struct { seqcount_t nr_sects_seq; #endif unsigned long stamp; -#ifdef CONFIG_SMP struct disk_stats __percpu *dkstats; -#else - struct disk_stats dkstats; -#endif struct percpu_ref ref; sector_t alignment_offset; diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h index ece607607a86..6644197980b9 100644 --- a/include/linux/part_stat.h +++ b/include/linux/part_stat.h @@ -4,19 +4,23 @@ #include +struct disk_stats { + u64 nsecs[NR_STAT_GROUPS]; + unsigned long sectors[NR_STAT_GROUPS]; + unsigned long ios[NR_STAT_GROUPS]; + unsigned long merges[NR_STAT_GROUPS]; + unsigned long io_ticks; + local_t in_flight[2]; +}; + /* * Macros to operate on percpu disk statistics: * - * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters - * and should be called between disk_stat_lock() and - * disk_stat_unlock(). + * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters and should + * be called between disk_stat_lock() and disk_stat_unlock(). * * part_stat_read() can be called at any time. - * - * part_stat_{add|set_all}() and {init|free}_part_stats are for - * internal use only. */ -#ifdef CONFIG_SMP #define part_stat_lock() ({ rcu_read_lock(); get_cpu(); }) #define part_stat_unlock() do { put_cpu(); rcu_read_unlock(); } while (0) @@ -44,43 +48,6 @@ static inline void part_stat_set_all(struct hd_struct *part, int value) sizeof(struct disk_stats)); } -static inline int init_part_stats(struct hd_struct *part) -{ - part->dkstats = alloc_percpu(struct disk_stats); - if (!part->dkstats) - return 0; - return 1; -} - -static inline void free_part_stats(struct hd_struct *part) -{ - free_percpu(part->dkstats); -} - -#else /* !CONFIG_SMP */ -#define part_stat_lock() ({ rcu_read_lock(); 0; }) -#define part_stat_unlock() rcu_read_unlock() - -#define part_stat_get(part, field) ((part)->dkstats.field) -#define part_stat_get_cpu(part, field, cpu) part_stat_get(part, field) -#define part_stat_read(part, field) part_stat_get(part, field) - -static inline void part_stat_set_all(struct hd_struct *part, int value) -{ - memset(&part->dkstats, value, sizeof(struct disk_stats)); -} - -static inline int init_part_stats(struct hd_struct *part) -{ - return 1; -} - -static inline void free_part_stats(struct hd_struct *part) -{ -} - -#endif /* CONFIG_SMP */ - #define part_stat_read_accum(part, field) \ (part_stat_read(part, field[STAT_READ]) + \ part_stat_read(part, field[STAT_WRITE]) + \ -- 2.11.0