From efe1f3a1d5833c0ddd61ee50dbef8908f65a0a5e Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 22 Jan 2021 10:33:06 +0800 Subject: scsi: sbitmap: Maintain allocation round_robin in sbitmap Currently the allocation round_robin info is maintained by sbitmap_queue. However, bit allocation really belongs to sbitmap. Move it there. Link: https://lore.kernel.org/r/20210122023317.687987-3-ming.lei@redhat.com Cc: Omar Sandoval Cc: Kashyap Desai Cc: Sumanesh Samanta Cc: Ewan D. Milne Cc: Hannes Reinecke Cc: virtualization@lists.linux-foundation.org Tested-by: Sumanesh Samanta Reviewed-by: Hannes Reinecke Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- lib/sbitmap.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) (limited to 'lib') diff --git a/lib/sbitmap.c b/lib/sbitmap.c index d693d9213ceb..7000636933b3 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -33,7 +33,7 @@ static inline bool sbitmap_deferred_clear(struct sbitmap_word *map) } int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, - gfp_t flags, int node) + gfp_t flags, int node, bool round_robin) { unsigned int bits_per_word; unsigned int i; @@ -58,6 +58,7 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, sb->shift = shift; sb->depth = depth; sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); + sb->round_robin = round_robin; if (depth == 0) { sb->map = NULL; @@ -129,14 +130,14 @@ static int __sbitmap_get_word(unsigned long *word, unsigned long depth, } static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index, - unsigned int alloc_hint, bool round_robin) + unsigned int alloc_hint) { struct sbitmap_word *map = &sb->map[index]; int nr; do { nr = __sbitmap_get_word(&map->word, map->depth, alloc_hint, - !round_robin); + !sb->round_robin); if (nr != -1) break; if (!sbitmap_deferred_clear(map)) @@ -146,7 +147,7 @@ static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index, return nr; } -int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint, bool round_robin) +int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint) { unsigned int i, index; int nr = -1; @@ -158,14 +159,13 @@ int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint, bool round_robin) * alloc_hint to find the right word index. No point in looping * twice in find_next_zero_bit() for that case. */ - if (round_robin) + if (sb->round_robin) alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); else alloc_hint = 0; for (i = 0; i < sb->map_nr; i++) { - nr = sbitmap_find_bit_in_index(sb, index, alloc_hint, - round_robin); + nr = sbitmap_find_bit_in_index(sb, index, alloc_hint); if (nr != -1) { nr += index << sb->shift; break; @@ -350,7 +350,8 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, int ret; int i; - ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node); + ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node, + round_robin); if (ret) return ret; @@ -382,7 +383,6 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, atomic_set(&sbq->ws[i].wait_cnt, sbq->wake_batch); } - sbq->round_robin = round_robin; return 0; } EXPORT_SYMBOL_GPL(sbitmap_queue_init_node); @@ -424,12 +424,12 @@ int __sbitmap_queue_get(struct sbitmap_queue *sbq) hint = depth ? prandom_u32() % depth : 0; this_cpu_write(*sbq->alloc_hint, hint); } - nr = sbitmap_get(&sbq->sb, hint, sbq->round_robin); + nr = sbitmap_get(&sbq->sb, hint); if (nr == -1) { /* If the map is full, a hint won't do us much good. */ this_cpu_write(*sbq->alloc_hint, 0); - } else if (nr == hint || unlikely(sbq->round_robin)) { + } else if (nr == hint || unlikely(sbq->sb.round_robin)) { /* Only update the hint if we used it. */ hint = nr + 1; if (hint >= depth - 1) @@ -460,7 +460,7 @@ int __sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, if (nr == -1) { /* If the map is full, a hint won't do us much good. */ this_cpu_write(*sbq->alloc_hint, 0); - } else if (nr == hint || unlikely(sbq->round_robin)) { + } else if (nr == hint || unlikely(sbq->sb.round_robin)) { /* Only update the hint if we used it. */ hint = nr + 1; if (hint >= depth - 1) @@ -576,7 +576,7 @@ void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr, smp_mb__after_atomic(); sbitmap_queue_wake_up(sbq); - if (likely(!sbq->round_robin && nr < sbq->sb.depth)) + if (likely(!sbq->sb.round_robin && nr < sbq->sb.depth)) *per_cpu_ptr(sbq->alloc_hint, cpu) = nr; } EXPORT_SYMBOL_GPL(sbitmap_queue_clear); @@ -633,7 +633,7 @@ void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) } seq_puts(m, "}\n"); - seq_printf(m, "round_robin=%d\n", sbq->round_robin); + seq_printf(m, "round_robin=%d\n", sbq->sb.round_robin); seq_printf(m, "min_shallow_depth=%u\n", sbq->min_shallow_depth); } EXPORT_SYMBOL_GPL(sbitmap_queue_show); -- cgit v1.2.3 From bf2c4282a10a92810ba83e85677a5273d6ca0df5 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 22 Jan 2021 10:33:07 +0800 Subject: scsi: sbitmap: Add helpers for updating allocation hint Add helpers for updating allocation hint so that we can avoid duplicate code. Prepare for moving allocation hint into sbitmap. Link: https://lore.kernel.org/r/20210122023317.687987-4-ming.lei@redhat.com Cc: Omar Sandoval Cc: Kashyap Desai Cc: Sumanesh Samanta Cc: Ewan D. Milne Cc: Hannes Reinecke Tested-by: Sumanesh Samanta Reviewed-by: Hannes Reinecke Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- lib/sbitmap.c | 93 ++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 54 insertions(+), 39 deletions(-) (limited to 'lib') diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 7000636933b3..2b43a6aefec3 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -9,6 +9,55 @@ #include #include +static int init_alloc_hint(struct sbitmap_queue *sbq, gfp_t flags) +{ + unsigned depth = sbq->sb.depth; + + sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags); + if (!sbq->alloc_hint) + return -ENOMEM; + + if (depth && !sbq->sb.round_robin) { + int i; + + for_each_possible_cpu(i) + *per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth; + } + + return 0; +} + +static inline unsigned update_alloc_hint_before_get(struct sbitmap_queue *sbq, + unsigned int depth) +{ + unsigned hint; + + hint = this_cpu_read(*sbq->alloc_hint); + if (unlikely(hint >= depth)) { + hint = depth ? prandom_u32() % depth : 0; + this_cpu_write(*sbq->alloc_hint, hint); + } + + return hint; +} + +static inline void update_alloc_hint_after_get(struct sbitmap_queue *sbq, + unsigned int depth, + unsigned int hint, + unsigned int nr) +{ + if (nr == -1) { + /* If the map is full, a hint won't do us much good. */ + this_cpu_write(*sbq->alloc_hint, 0); + } else if (nr == hint || unlikely(sbq->sb.round_robin)) { + /* Only update the hint if we used it. */ + hint = nr + 1; + if (hint >= depth - 1) + hint = 0; + this_cpu_write(*sbq->alloc_hint, hint); + } +} + /* * See if we have deferred clears that we can batch move */ @@ -355,17 +404,11 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, if (ret) return ret; - sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags); - if (!sbq->alloc_hint) { + if (init_alloc_hint(sbq, flags) != 0) { sbitmap_free(&sbq->sb); return -ENOMEM; } - if (depth && !round_robin) { - for_each_possible_cpu(i) - *per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth; - } - sbq->min_shallow_depth = UINT_MAX; sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); atomic_set(&sbq->wake_index, 0); @@ -418,24 +461,10 @@ int __sbitmap_queue_get(struct sbitmap_queue *sbq) unsigned int hint, depth; int nr; - hint = this_cpu_read(*sbq->alloc_hint); depth = READ_ONCE(sbq->sb.depth); - if (unlikely(hint >= depth)) { - hint = depth ? prandom_u32() % depth : 0; - this_cpu_write(*sbq->alloc_hint, hint); - } + hint = update_alloc_hint_before_get(sbq, depth); nr = sbitmap_get(&sbq->sb, hint); - - if (nr == -1) { - /* If the map is full, a hint won't do us much good. */ - this_cpu_write(*sbq->alloc_hint, 0); - } else if (nr == hint || unlikely(sbq->sb.round_robin)) { - /* Only update the hint if we used it. */ - hint = nr + 1; - if (hint >= depth - 1) - hint = 0; - this_cpu_write(*sbq->alloc_hint, hint); - } + update_alloc_hint_after_get(sbq, depth, hint, nr); return nr; } @@ -449,24 +478,10 @@ int __sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth); - hint = this_cpu_read(*sbq->alloc_hint); depth = READ_ONCE(sbq->sb.depth); - if (unlikely(hint >= depth)) { - hint = depth ? prandom_u32() % depth : 0; - this_cpu_write(*sbq->alloc_hint, hint); - } + hint = update_alloc_hint_before_get(sbq, depth); nr = sbitmap_get_shallow(&sbq->sb, hint, shallow_depth); - - if (nr == -1) { - /* If the map is full, a hint won't do us much good. */ - this_cpu_write(*sbq->alloc_hint, 0); - } else if (nr == hint || unlikely(sbq->sb.round_robin)) { - /* Only update the hint if we used it. */ - hint = nr + 1; - if (hint >= depth - 1) - hint = 0; - this_cpu_write(*sbq->alloc_hint, hint); - } + update_alloc_hint_after_get(sbq, depth, hint, nr); return nr; } -- cgit v1.2.3 From c548e62bcf6adc7066ff201e9ecc88e536dd8890 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 22 Jan 2021 10:33:08 +0800 Subject: scsi: sbitmap: Move allocation hint into sbitmap Allocation hint should have belonged to sbitmap. Also, when sbitmap's depth is high and there is no need to use mulitple wakeup queues, user can benefit from percpu allocation hint too. Move allocation hint into sbitmap, then SCSI device queue can benefit from allocation hint when converting to plain sbitmap. Convert vhost/scsi.c to use sbitmap allocation with percpu alloc hint. This is more efficient than the previous approach. Link: https://lore.kernel.org/r/20210122023317.687987-5-ming.lei@redhat.com Cc: Omar Sandoval Cc: Kashyap Desai Cc: Sumanesh Samanta Cc: Ewan D. Milne Cc: Mike Christie Cc: virtualization@lists.linux-foundation.org Tested-by: Sumanesh Samanta Reviewed-by: Hannes Reinecke Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- block/blk-mq.c | 2 +- block/kyber-iosched.c | 2 +- drivers/vhost/scsi.c | 4 +- include/linux/sbitmap.h | 41 +++++++++++------- lib/sbitmap.c | 112 ++++++++++++++++++++++++++++-------------------- 5 files changed, 96 insertions(+), 65 deletions(-) (limited to 'lib') diff --git a/block/blk-mq.c b/block/blk-mq.c index f133bbfa6cd4..2e8c94e00f58 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2702,7 +2702,7 @@ blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, goto free_cpumask; if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), - gfp, node, false)) + gfp, node, false, false)) goto free_ctxs; hctx->nr_ctx = 0; diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c index d39ac13f0105..8969e122f081 100644 --- a/block/kyber-iosched.c +++ b/block/kyber-iosched.c @@ -479,7 +479,7 @@ static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) for (i = 0; i < KYBER_NUM_DOMAINS; i++) { if (sbitmap_init_node(&khd->kcq_map[i], hctx->nr_ctx, ilog2(8), GFP_KERNEL, hctx->numa_node, - false)) { + false, false)) { while (--i >= 0) sbitmap_free(&khd->kcq_map[i]); goto err_kcqs; diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 3412a3ad28e6..936584250a0b 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -614,7 +614,7 @@ vhost_scsi_get_cmd(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg, return ERR_PTR(-EIO); } - tag = sbitmap_get(&svq->scsi_tags, 0); + tag = sbitmap_get(&svq->scsi_tags); if (tag < 0) { pr_err("Unable to obtain tag for vhost_scsi_cmd\n"); return ERR_PTR(-ENOMEM); @@ -1512,7 +1512,7 @@ static int vhost_scsi_setup_vq_cmds(struct vhost_virtqueue *vq, int max_cmds) return 0; if (sbitmap_init_node(&svq->scsi_tags, max_cmds, -1, GFP_KERNEL, - NUMA_NO_NODE, false)) + NUMA_NO_NODE, false, true)) return -ENOMEM; svq->max_cmds = max_cmds; diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index 734ee6214cd6..247776fcc02c 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -65,6 +65,14 @@ struct sbitmap { * @map: Allocated bitmap. */ struct sbitmap_word *map; + + /* + * @alloc_hint: Cache of last successfully allocated or freed bit. + * + * This is per-cpu, which allows multiple users to stick to different + * cachelines until the map is exhausted. + */ + unsigned int __percpu *alloc_hint; }; #define SBQ_WAIT_QUEUES 8 @@ -100,14 +108,6 @@ struct sbitmap_queue { */ struct sbitmap sb; - /* - * @alloc_hint: Cache of last successfully allocated or freed bit. - * - * This is per-cpu, which allows multiple users to stick to different - * cachelines until the map is exhausted. - */ - unsigned int __percpu *alloc_hint; - /** * @wake_batch: Number of bits which must be freed before we wake up any * waiters. @@ -147,11 +147,13 @@ struct sbitmap_queue { * @round_robin: If true, be stricter about allocation order; always allocate * starting from the last allocated bit. This is less efficient * than the default behavior (false). + * @alloc_hint: If true, apply percpu hint for where to start searching for + * a free bit. * * Return: Zero on success or negative errno on failure. */ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, - gfp_t flags, int node, bool round_robin); + gfp_t flags, int node, bool round_robin, bool alloc_hint); /** * sbitmap_free() - Free memory used by a &struct sbitmap. @@ -159,6 +161,7 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, */ static inline void sbitmap_free(struct sbitmap *sb) { + free_percpu(sb->alloc_hint); kfree(sb->map); sb->map = NULL; } @@ -176,19 +179,17 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth); /** * sbitmap_get() - Try to allocate a free bit from a &struct sbitmap. * @sb: Bitmap to allocate from. - * @alloc_hint: Hint for where to start searching for a free bit. * * This operation provides acquire barrier semantics if it succeeds. * * Return: Non-negative allocated bit number if successful, -1 otherwise. */ -int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint); +int sbitmap_get(struct sbitmap *sb); /** * sbitmap_get_shallow() - Try to allocate a free bit from a &struct sbitmap, * limiting the depth used from each word. * @sb: Bitmap to allocate from. - * @alloc_hint: Hint for where to start searching for a free bit. * @shallow_depth: The maximum number of bits to allocate from a single word. * * This rather specific operation allows for having multiple users with @@ -200,8 +201,7 @@ int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint); * * Return: Non-negative allocated bit number if successful, -1 otherwise. */ -int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint, - unsigned long shallow_depth); +int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth); /** * sbitmap_any_bit_set() - Check for a set bit in a &struct sbitmap. @@ -315,6 +315,18 @@ static inline void sbitmap_deferred_clear_bit(struct sbitmap *sb, unsigned int b set_bit(SB_NR_TO_BIT(sb, bitnr), addr); } +/* + * Pair of sbitmap_get, and this one applies both cleared bit and + * allocation hint. + */ +static inline void sbitmap_put(struct sbitmap *sb, unsigned int bitnr) +{ + sbitmap_deferred_clear_bit(sb, bitnr); + + if (likely(sb->alloc_hint && !sb->round_robin && bitnr < sb->depth)) + *this_cpu_ptr(sb->alloc_hint) = bitnr; +} + static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) { return test_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr)); @@ -363,7 +375,6 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, static inline void sbitmap_queue_free(struct sbitmap_queue *sbq) { kfree(sbq->ws); - free_percpu(sbq->alloc_hint); sbitmap_free(&sbq->sb); } diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 2b43a6aefec3..e395435654aa 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -9,52 +9,51 @@ #include #include -static int init_alloc_hint(struct sbitmap_queue *sbq, gfp_t flags) +static int init_alloc_hint(struct sbitmap *sb, gfp_t flags) { - unsigned depth = sbq->sb.depth; + unsigned depth = sb->depth; - sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags); - if (!sbq->alloc_hint) + sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags); + if (!sb->alloc_hint) return -ENOMEM; - if (depth && !sbq->sb.round_robin) { + if (depth && !sb->round_robin) { int i; for_each_possible_cpu(i) - *per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth; + *per_cpu_ptr(sb->alloc_hint, i) = prandom_u32() % depth; } - return 0; } -static inline unsigned update_alloc_hint_before_get(struct sbitmap_queue *sbq, +static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb, unsigned int depth) { unsigned hint; - hint = this_cpu_read(*sbq->alloc_hint); + hint = this_cpu_read(*sb->alloc_hint); if (unlikely(hint >= depth)) { hint = depth ? prandom_u32() % depth : 0; - this_cpu_write(*sbq->alloc_hint, hint); + this_cpu_write(*sb->alloc_hint, hint); } return hint; } -static inline void update_alloc_hint_after_get(struct sbitmap_queue *sbq, +static inline void update_alloc_hint_after_get(struct sbitmap *sb, unsigned int depth, unsigned int hint, unsigned int nr) { if (nr == -1) { /* If the map is full, a hint won't do us much good. */ - this_cpu_write(*sbq->alloc_hint, 0); - } else if (nr == hint || unlikely(sbq->sb.round_robin)) { + this_cpu_write(*sb->alloc_hint, 0); + } else if (nr == hint || unlikely(sb->round_robin)) { /* Only update the hint if we used it. */ hint = nr + 1; if (hint >= depth - 1) hint = 0; - this_cpu_write(*sbq->alloc_hint, hint); + this_cpu_write(*sb->alloc_hint, hint); } } @@ -82,7 +81,8 @@ static inline bool sbitmap_deferred_clear(struct sbitmap_word *map) } int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, - gfp_t flags, int node, bool round_robin) + gfp_t flags, int node, bool round_robin, + bool alloc_hint) { unsigned int bits_per_word; unsigned int i; @@ -114,9 +114,18 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, return 0; } + if (alloc_hint) { + if (init_alloc_hint(sb, flags)) + return -ENOMEM; + } else { + sb->alloc_hint = NULL; + } + sb->map = kcalloc_node(sb->map_nr, sizeof(*sb->map), flags, node); - if (!sb->map) + if (!sb->map) { + free_percpu(sb->alloc_hint); return -ENOMEM; + } for (i = 0; i < sb->map_nr; i++) { sb->map[i].depth = min(depth, bits_per_word); @@ -196,7 +205,7 @@ static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index, return nr; } -int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint) +static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint) { unsigned int i, index; int nr = -1; @@ -228,10 +237,27 @@ int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint) return nr; } + +int sbitmap_get(struct sbitmap *sb) +{ + int nr; + unsigned int hint, depth; + + if (WARN_ON_ONCE(unlikely(!sb->alloc_hint))) + return -1; + + depth = READ_ONCE(sb->depth); + hint = update_alloc_hint_before_get(sb, depth); + nr = __sbitmap_get(sb, hint); + update_alloc_hint_after_get(sb, depth, hint, nr); + + return nr; +} EXPORT_SYMBOL_GPL(sbitmap_get); -int sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint, - unsigned long shallow_depth) +static int __sbitmap_get_shallow(struct sbitmap *sb, + unsigned int alloc_hint, + unsigned long shallow_depth) { unsigned int i, index; int nr = -1; @@ -263,6 +289,22 @@ again: return nr; } + +int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth) +{ + int nr; + unsigned int hint, depth; + + if (WARN_ON_ONCE(unlikely(!sb->alloc_hint))) + return -1; + + depth = READ_ONCE(sb->depth); + hint = update_alloc_hint_before_get(sb, depth); + nr = __sbitmap_get_shallow(sb, hint, shallow_depth); + update_alloc_hint_after_get(sb, depth, hint, nr); + + return nr; +} EXPORT_SYMBOL_GPL(sbitmap_get_shallow); bool sbitmap_any_bit_set(const struct sbitmap *sb) @@ -400,15 +442,10 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, int i; ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node, - round_robin); + round_robin, true); if (ret) return ret; - if (init_alloc_hint(sbq, flags) != 0) { - sbitmap_free(&sbq->sb); - return -ENOMEM; - } - sbq->min_shallow_depth = UINT_MAX; sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); atomic_set(&sbq->wake_index, 0); @@ -416,7 +453,6 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); if (!sbq->ws) { - free_percpu(sbq->alloc_hint); sbitmap_free(&sbq->sb); return -ENOMEM; } @@ -458,32 +494,16 @@ EXPORT_SYMBOL_GPL(sbitmap_queue_resize); int __sbitmap_queue_get(struct sbitmap_queue *sbq) { - unsigned int hint, depth; - int nr; - - depth = READ_ONCE(sbq->sb.depth); - hint = update_alloc_hint_before_get(sbq, depth); - nr = sbitmap_get(&sbq->sb, hint); - update_alloc_hint_after_get(sbq, depth, hint, nr); - - return nr; + return sbitmap_get(&sbq->sb); } EXPORT_SYMBOL_GPL(__sbitmap_queue_get); int __sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, unsigned int shallow_depth) { - unsigned int hint, depth; - int nr; - WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth); - depth = READ_ONCE(sbq->sb.depth); - hint = update_alloc_hint_before_get(sbq, depth); - nr = sbitmap_get_shallow(&sbq->sb, hint, shallow_depth); - update_alloc_hint_after_get(sbq, depth, hint, nr); - - return nr; + return sbitmap_get_shallow(&sbq->sb, shallow_depth); } EXPORT_SYMBOL_GPL(__sbitmap_queue_get_shallow); @@ -592,7 +612,7 @@ void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr, sbitmap_queue_wake_up(sbq); if (likely(!sbq->sb.round_robin && nr < sbq->sb.depth)) - *per_cpu_ptr(sbq->alloc_hint, cpu) = nr; + *per_cpu_ptr(sbq->sb.alloc_hint, cpu) = nr; } EXPORT_SYMBOL_GPL(sbitmap_queue_clear); @@ -630,7 +650,7 @@ void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) if (!first) seq_puts(m, ", "); first = false; - seq_printf(m, "%u", *per_cpu_ptr(sbq->alloc_hint, i)); + seq_printf(m, "%u", *per_cpu_ptr(sbq->sb.alloc_hint, i)); } seq_puts(m, "}\n"); -- cgit v1.2.3 From cbb9950b41dd9dfb7c2be3429ba09f83b8b1ff98 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 22 Jan 2021 10:33:09 +0800 Subject: scsi: sbitmap: Export sbitmap_weight SCSI's .device_busy will be converted to sbitmap and sbitmap_weight is needed. Export the helper. The only existing user of sbitmap_weight() uses it to find out how many bits are set and not cleared. Align sbitmap_weight() meaning with this usage model. Link: https://lore.kernel.org/r/20210122023317.687987-6-ming.lei@redhat.com Cc: Omar Sandoval Cc: Kashyap Desai Cc: Sumanesh Samanta Cc: Ewan D. Milne Tested-by: Sumanesh Samanta Reviewed-by: Hannes Reinecke Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- include/linux/sbitmap.h | 10 ++++++++++ lib/sbitmap.c | 11 ++++++----- 2 files changed, 16 insertions(+), 5 deletions(-) (limited to 'lib') diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index 247776fcc02c..c65ba887dcc3 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -341,6 +341,16 @@ static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) */ void sbitmap_show(struct sbitmap *sb, struct seq_file *m); + +/** + * sbitmap_weight() - Return how many set and not cleared bits in a &struct + * sbitmap. + * @sb: Bitmap to check. + * + * Return: How many set and not cleared bits set + */ +unsigned int sbitmap_weight(const struct sbitmap *sb); + /** * sbitmap_bitmap_show() - Write a hex dump of a &struct sbitmap to a &struct * seq_file. diff --git a/lib/sbitmap.c b/lib/sbitmap.c index e395435654aa..73da26ad021e 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -334,20 +334,21 @@ static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set) return weight; } -static unsigned int sbitmap_weight(const struct sbitmap *sb) +static unsigned int sbitmap_cleared(const struct sbitmap *sb) { - return __sbitmap_weight(sb, true); + return __sbitmap_weight(sb, false); } -static unsigned int sbitmap_cleared(const struct sbitmap *sb) +unsigned int sbitmap_weight(const struct sbitmap *sb) { - return __sbitmap_weight(sb, false); + return __sbitmap_weight(sb, true) - sbitmap_cleared(sb); } +EXPORT_SYMBOL_GPL(sbitmap_weight); void sbitmap_show(struct sbitmap *sb, struct seq_file *m) { seq_printf(m, "depth=%u\n", sb->depth); - seq_printf(m, "busy=%u\n", sbitmap_weight(sb) - sbitmap_cleared(sb)); + seq_printf(m, "busy=%u\n", sbitmap_weight(sb)); seq_printf(m, "cleared=%u\n", sbitmap_cleared(sb)); seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift); seq_printf(m, "map_nr=%u\n", sb->map_nr); -- cgit v1.2.3 From 2d13b1ea9f4affdaa7af0e0e4a1358d28f80c54f Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 22 Jan 2021 10:33:10 +0800 Subject: scsi: sbitmap: Add sbitmap_calculate_shift() helper Move code for calculating default shift into a public helper which can be used by SCSI. Link: https://lore.kernel.org/r/20210122023317.687987-7-ming.lei@redhat.com Cc: Omar Sandoval Cc: Kashyap Desai Cc: Sumanesh Samanta Cc: Ewan D. Milne Tested-by: Sumanesh Samanta Reviewed-by: Hannes Reinecke Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- include/linux/sbitmap.h | 18 ++++++++++++++++++ lib/sbitmap.c | 16 +++------------- 2 files changed, 21 insertions(+), 13 deletions(-) (limited to 'lib') diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index c65ba887dcc3..3087e1f15fdd 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -332,6 +332,24 @@ static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) return test_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr)); } +static inline int sbitmap_calculate_shift(unsigned int depth) +{ + int shift = ilog2(BITS_PER_LONG); + + /* + * If the bitmap is small, shrink the number of bits per word so + * we spread over a few cachelines, at least. If less than 4 + * bits, just forget about it, it's not going to work optimally + * anyway. + */ + if (depth >= 4) { + while ((4U << shift) > depth) + shift--; + } + + return shift; +} + /** * sbitmap_show() - Dump &struct sbitmap information to a &struct seq_file. * @sb: Bitmap to show. diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 73da26ad021e..47b3691058eb 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -87,19 +87,9 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, unsigned int bits_per_word; unsigned int i; - if (shift < 0) { - shift = ilog2(BITS_PER_LONG); - /* - * If the bitmap is small, shrink the number of bits per word so - * we spread over a few cachelines, at least. If less than 4 - * bits, just forget about it, it's not going to work optimally - * anyway. - */ - if (depth >= 4) { - while ((4U << shift) > depth) - shift--; - } - } + if (shift < 0) + shift = sbitmap_calculate_shift(depth); + bits_per_word = 1U << shift; if (bits_per_word > BITS_PER_LONG) return -EINVAL; -- cgit v1.2.3