// SPDX-License-Identifier: GPL-2.0-only/* * Copyright (C) 2016 Facebook * Copyright (C) 2013-2014 Jens Axboe */ #include <linux/sched.h>#include <linux/random.h>#include <linux/sbitmap.h>#include <linux/seq_file.h> static int init_alloc_hint(struct sbitmap *sb, gfp_t flags){ unsigned depth = sb->depth; sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags); if (!sb->alloc_hint) return -ENOMEM; if (depth && !sb->round_robin) { int i; for_each_possible_cpu(i) *per_cpu_ptr(sb->alloc_hint, i) = get_random_u32_below(depth); } return 0;} static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb, unsigned int depth){ unsigned hint; hint = this_cpu_read(*sb->alloc_hint); if (unlikely(hint >= depth)) { hint = depth ? get_random_u32_below(depth) : 0; this_cpu_write(*sb->alloc_hint, hint); } return hint;} 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(*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(*sb->alloc_hint, hint); }} /* * See if we have deferred clears that we can batch move */static inline bool sbitmap_deferred_clear(struct sbitmap_word *map, unsigned int depth, unsigned int alloc_hint, bool wrap){ unsigned long mask, word_mask; guard(raw_spinlock_irqsave)(&map->swap_lock); if (!map->cleared) { if (depth == 0) return false; word_mask = (~0UL) >> (BITS_PER_LONG - depth); /* * The current behavior is to always retry after moving * ->cleared to word, and we change it to retry in case * of any free bits. To avoid an infinite loop, we need * to take wrap & alloc_hint into account, otherwise a * soft lockup may occur. */ if (!wrap && alloc_hint) word_mask &= ~((1UL << alloc_hint) - 1); return (READ_ONCE(map->word) & word_mask) != word_mask; } /* * First get a stable cleared mask, setting the old mask to 0. */ mask = xchg(&map->cleared, 0); /* * Now clear the masked bits in our free word */ atomic_long_andnot(mask, (atomic_long_t *)&map->word); BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(map->word)); return true;} int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, gfp_t flags, int node, bool round_robin, bool alloc_hint){ unsigned int bits_per_word; int i; if (shift < 0) shift = sbitmap_calculate_shift(depth); bits_per_word = 1U << shift; if (bits_per_word > BITS_PER_LONG) return -EINVAL; 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; return 0; } if (alloc_hint) { if (init_alloc_hint(sb, flags)) return -ENOMEM; } else { sb->alloc_hint = NULL; } sb->map = kvzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node); if (!sb->map) { free_percpu(sb->alloc_hint); return -ENOMEM; } for (i = 0; i < sb->map_nr; i++) raw_spin_lock_init(&sb->map[i].swap_lock); return 0;}EXPORT_SYMBOL_GPL(sbitmap_init_node); void sbitmap_resize(struct sbitmap *sb, unsigned int depth){ unsigned int bits_per_word = 1U << sb->shift; unsigned int i; for (i = 0; i < sb->map_nr; i++) sbitmap_deferred_clear(&sb->map[i], 0, 0, 0); sb->depth = depth; sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);}EXPORT_SYMBOL_GPL(sbitmap_resize); static int __sbitmap_get_word(unsigned long *word, unsigned long depth, unsigned int hint, bool wrap){ int nr; /* don't wrap if starting from 0 */ wrap = wrap && hint; while (1) { nr = find_next_zero_bit(word, depth, hint); if (unlikely(nr >= depth)) { /* * We started with an offset, and we didn't reset the * offset to 0 in a failure case, so start from 0 to * exhaust the map. */ if (hint && wrap) { hint = 0; continue; } return -1; } if (!test_and_set_bit_lock(nr, word)) break; hint = nr + 1; if (hint >= depth - 1) hint = 0; } return nr;} static int sbitmap_find_bit_in_word(struct sbitmap_word *map, unsigned int depth, unsigned int alloc_hint, bool wrap){ int nr; do { nr = __sbitmap_get_word(&map->word, depth, alloc_hint, wrap); if (nr != -1) break; if (!sbitmap_deferred_clear(map, depth, alloc_hint, wrap)) break; } while (1); return nr;} static unsigned int __map_depth_with_shallow(const struct sbitmap *sb, int index, unsigned int shallow_depth){ u64 shallow_word_depth; unsigned int word_depth, reminder; word_depth = __map_depth(sb, index); if (shallow_depth >= sb->depth) return word_depth; shallow_word_depth = word_depth * shallow_depth; reminder = do_div(shallow_word_depth, sb->depth); if (reminder >= (index + 1) * word_depth) shallow_word_depth++; return (unsigned int)shallow_word_depth;} static int sbitmap_find_bit(struct sbitmap *sb, unsigned int shallow_depth, unsigned int index, unsigned int alloc_hint, bool wrap){ unsigned int i; int nr = -1; for (i = 0; i < sb->map_nr; i++) { unsigned int depth = __map_depth_with_shallow(sb, index, shallow_depth); if (depth) nr = sbitmap_find_bit_in_word(&sb->map[index], depth, alloc_hint, wrap); if (nr != -1) { nr += index << sb->shift; break; } /* Jump to next index. */ alloc_hint = 0; if (++index >= sb->map_nr) index = 0; } return nr;} static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint){ unsigned int index; index = SB_NR_TO_INDEX(sb, alloc_hint); /* * Unless we're doing round robin tag allocation, just use the * alloc_hint to find the right word index. No point in looping * twice in find_next_zero_bit() for that case. */ if (sb->round_robin) alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); else alloc_hint = 0; return sbitmap_find_bit(sb, UINT_MAX, index, alloc_hint, !sb->round_robin);} 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); static int __sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint, unsigned long shallow_depth){ unsigned int index; index = SB_NR_TO_INDEX(sb, alloc_hint); alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); return sbitmap_find_bit(sb, shallow_depth, index, alloc_hint, true);} /** * 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. * @shallow_depth: The maximum number of bits to allocate from the bitmap. * * This rather specific operation allows for having multiple users with * different allocation limits. E.g., there can be a high-priority class that * uses sbitmap_get() and a low-priority class that uses sbitmap_get_shallow() * with a @shallow_depth of (sb->depth >> 1). Then, the low-priority * class can only allocate half of the total bits in the bitmap, preventing it * from starving out the high-priority class. * * Return: Non-negative allocated bit number if successful, -1 otherwise. */static 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;} bool sbitmap_any_bit_set(const struct sbitmap *sb){ unsigned int i; for (i = 0; i < sb->map_nr; i++) { if (sb->map[i].word & ~sb->map[i].cleared) return true; } return false;}EXPORT_SYMBOL_GPL(sbitmap_any_bit_set); static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set){ unsigned int i, weight = 0; for (i = 0; i < sb->map_nr; i++) { const struct sbitmap_word *word = &sb->map[i]; unsigned int word_depth = __map_depth(sb, i); if (set) weight += bitmap_weight(&word->word, word_depth); else weight += bitmap_weight(&word->cleared, word_depth); } return weight;} static unsigned int sbitmap_cleared(const struct sbitmap *sb){ return __sbitmap_weight(sb, false);} unsigned int sbitmap_weight(const struct sbitmap *sb){ 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)); 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);}EXPORT_SYMBOL_GPL(sbitmap_show); static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte){ if ((offset & 0xf) == 0) { if (offset != 0) seq_putc(m, '\n'); seq_printf(m, "%08x:", offset); } if ((offset & 0x1) == 0) seq_putc(m, ' '); seq_printf(m, "%02x", byte);} void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m){ u8 byte = 0; unsigned int byte_bits = 0; unsigned int offset = 0; int i; for (i = 0; i < sb->map_nr; i++) { unsigned long word = READ_ONCE(sb->map[i].word); unsigned long cleared = READ_ONCE(sb->map[i].cleared); unsigned int word_bits = __map_depth(sb, i); word &= ~cleared; while (word_bits > 0) { unsigned int bits = min(8 - byte_bits, word_bits); byte |= (word & (BIT(bits) - 1)) << byte_bits; byte_bits += bits; if (byte_bits == 8) { emit_byte(m, offset, byte); byte = 0; byte_bits = 0; offset++; } word >>= bits; word_bits -= bits; } } if (byte_bits) { emit_byte(m, offset, byte); offset++; } if (offset) seq_putc(m, '\n');}EXPORT_SYMBOL_GPL(sbitmap_bitmap_show); static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq, unsigned int depth){ return clamp_t(unsigned int, min(depth, sbq->min_shallow_depth) / SBQ_WAIT_QUEUES, 1, SBQ_WAKE_BATCH);} int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, int shift, bool round_robin, gfp_t flags, int node){ int ret; int i; ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node, round_robin, true); if (ret) return ret; sbq->min_shallow_depth = UINT_MAX; sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); atomic_set(&sbq->wake_index, 0); atomic_set(&sbq->ws_active, 0); atomic_set(&sbq->completion_cnt, 0); atomic_set(&sbq->wakeup_cnt, 0); sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); if (!sbq->ws) { sbitmap_free(&sbq->sb); return -ENOMEM; } for (i = 0; i < SBQ_WAIT_QUEUES; i++) init_waitqueue_head(&sbq->ws[i].wait); return 0;}EXPORT_SYMBOL_GPL(sbitmap_queue_init_node); static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq, unsigned int depth){ unsigned int wake_batch; wake_batch = sbq_calc_wake_batch(sbq, depth); if (sbq->wake_batch != wake_batch) WRITE_ONCE(sbq->wake_batch, wake_batch);} void sbitmap_queue_recalculate_wake_batch(struct sbitmap_queue *sbq, unsigned int users){ unsigned int wake_batch; unsigned int depth = (sbq->sb.depth + users - 1) / users; wake_batch = clamp_val(depth / SBQ_WAIT_QUEUES, 1, SBQ_WAKE_BATCH); WRITE_ONCE(sbq->wake_batch, wake_batch);}EXPORT_SYMBOL_GPL(sbitmap_queue_recalculate_wake_batch);Lines 1–500 of 802. 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// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2016 Facebook * Copyright (C) 2013-2014 Jens Axboe */ #include <linux/sched.h> #include <linux/random.h> #include <linux/sbitmap.h> #include <linux/seq_file.h> static int init_alloc_hint(struct sbitmap *sb, gfp_t flags) { unsigned depth = sb->depth; sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags); if (!sb->alloc_hint) return -ENOMEM; if (depth && !sb->round_robin) { int i; for_each_possible_cpu(i) *per_cpu_ptr(sb->alloc_hint, i) = get_random_u32_below(depth); } return 0; } static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb, unsigned int depth) { unsigned hint; hint = this_cpu_read(*sb->alloc_hint); if (unlikely(hint >= depth)) { hint = depth ? get_random_u32_below(depth) : 0; this_cpu_write(*sb->alloc_hint, hint); } return hint; } 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(*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(*sb->alloc_hint, hint); } } /* * See if we have deferred clears that we can batch move */ static inline bool sbitmap_deferred_clear(struct sbitmap_word *map, unsigned int depth, unsigned int alloc_hint, bool wrap) { unsigned long mask, word_mask; guard(raw_spinlock_irqsave)(&map->swap_lock); if (!map->cleared) { if (depth == 0) return false; word_mask = (~0UL) >> (BITS_PER_LONG - depth); /* * The current behavior is to always retry after moving * ->cleared to word, and we change it to retry in case * of any free bits. To avoid an infinite loop, we need * to take wrap & alloc_hint into account, otherwise a * soft lockup may occur. */ if (!wrap && alloc_hint) word_mask &= ~((1UL << alloc_hint) - 1); return (READ_ONCE(map->word) & word_mask) != word_mask; } /* * First get a stable cleared mask, setting the old mask to 0. */ mask = xchg(&map->cleared, 0); /* * Now clear the masked bits in our free word */ atomic_long_andnot(mask, (atomic_long_t *)&map->word); BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(map->word)); return true; } int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, gfp_t flags, int node, bool round_robin, bool alloc_hint) { unsigned int bits_per_word; int i; if (shift < 0) shift = sbitmap_calculate_shift(depth); bits_per_word = 1U << shift; if (bits_per_word > BITS_PER_LONG) return -EINVAL; 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; return 0; } if (alloc_hint) { if (init_alloc_hint(sb, flags)) return -ENOMEM; } else { sb->alloc_hint = NULL; } sb->map = kvzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node); if (!sb->map) { free_percpu(sb->alloc_hint); return -ENOMEM; } for (i = 0; i < sb->map_nr; i++) raw_spin_lock_init(&sb->map[i].swap_lock); return 0; } EXPORT_SYMBOL_GPL(sbitmap_init_node); void sbitmap_resize(struct sbitmap *sb, unsigned int depth) { unsigned int bits_per_word = 1U << sb->shift; unsigned int i; for (i = 0; i < sb->map_nr; i++) sbitmap_deferred_clear(&sb->map[i], 0, 0, 0); sb->depth = depth; sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); } EXPORT_SYMBOL_GPL(sbitmap_resize); static int __sbitmap_get_word(unsigned long *word, unsigned long depth, unsigned int hint, bool wrap) { int nr; /* don't wrap if starting from 0 */ wrap = wrap && hint; while (1) { nr = find_next_zero_bit(word, depth, hint); if (unlikely(nr >= depth)) { /* * We started with an offset, and we didn't reset the * offset to 0 in a failure case, so start from 0 to * exhaust the map. */ if (hint && wrap) { hint = 0; continue; } return -1; } if (!test_and_set_bit_lock(nr, word)) break; hint = nr + 1; if (hint >= depth - 1) hint = 0; } return nr; } static int sbitmap_find_bit_in_word(struct sbitmap_word *map, unsigned int depth, unsigned int alloc_hint, bool wrap) { int nr; do { nr = __sbitmap_get_word(&map->word, depth, alloc_hint, wrap); if (nr != -1) break; if (!sbitmap_deferred_clear(map, depth, alloc_hint, wrap)) break; } while (1); return nr; } static unsigned int __map_depth_with_shallow(const struct sbitmap *sb, int index, unsigned int shallow_depth) { u64 shallow_word_depth; unsigned int word_depth, reminder; word_depth = __map_depth(sb, index); if (shallow_depth >= sb->depth) return word_depth; shallow_word_depth = word_depth * shallow_depth; reminder = do_div(shallow_word_depth, sb->depth); if (reminder >= (index + 1) * word_depth) shallow_word_depth++; return (unsigned int)shallow_word_depth; } static int sbitmap_find_bit(struct sbitmap *sb, unsigned int shallow_depth, unsigned int index, unsigned int alloc_hint, bool wrap) { unsigned int i; int nr = -1; for (i = 0; i < sb->map_nr; i++) { unsigned int depth = __map_depth_with_shallow(sb, index, shallow_depth); if (depth) nr = sbitmap_find_bit_in_word(&sb->map[index], depth, alloc_hint, wrap); if (nr != -1) { nr += index << sb->shift; break; } /* Jump to next index. */ alloc_hint = 0; if (++index >= sb->map_nr) index = 0; } return nr; } static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint) { unsigned int index; index = SB_NR_TO_INDEX(sb, alloc_hint); /* * Unless we're doing round robin tag allocation, just use the * alloc_hint to find the right word index. No point in looping * twice in find_next_zero_bit() for that case. */ if (sb->round_robin) alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); else alloc_hint = 0; return sbitmap_find_bit(sb, UINT_MAX, index, alloc_hint, !sb->round_robin); } 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); static int __sbitmap_get_shallow(struct sbitmap *sb, unsigned int alloc_hint, unsigned long shallow_depth) { unsigned int index; index = SB_NR_TO_INDEX(sb, alloc_hint); alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); return sbitmap_find_bit(sb, shallow_depth, index, alloc_hint, true); } /** * 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. * @shallow_depth: The maximum number of bits to allocate from the bitmap. * * This rather specific operation allows for having multiple users with * different allocation limits. E.g., there can be a high-priority class that * uses sbitmap_get() and a low-priority class that uses sbitmap_get_shallow() * with a @shallow_depth of (sb->depth >> 1). Then, the low-priority * class can only allocate half of the total bits in the bitmap, preventing it * from starving out the high-priority class. * * Return: Non-negative allocated bit number if successful, -1 otherwise. */ static 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; } bool sbitmap_any_bit_set(const struct sbitmap *sb) { unsigned int i; for (i = 0; i < sb->map_nr; i++) { if (sb->map[i].word & ~sb->map[i].cleared) return true; } return false; } EXPORT_SYMBOL_GPL(sbitmap_any_bit_set); static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set) { unsigned int i, weight = 0; for (i = 0; i < sb->map_nr; i++) { const struct sbitmap_word *word = &sb->map[i]; unsigned int word_depth = __map_depth(sb, i); if (set) weight += bitmap_weight(&word->word, word_depth); else weight += bitmap_weight(&word->cleared, word_depth); } return weight; } static unsigned int sbitmap_cleared(const struct sbitmap *sb) { return __sbitmap_weight(sb, false); } unsigned int sbitmap_weight(const struct sbitmap *sb) { 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)); 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); } EXPORT_SYMBOL_GPL(sbitmap_show); static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte) { if ((offset & 0xf) == 0) { if (offset != 0) seq_putc(m, '\n'); seq_printf(m, "%08x:", offset); } if ((offset & 0x1) == 0) seq_putc(m, ' '); seq_printf(m, "%02x", byte); } void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m) { u8 byte = 0; unsigned int byte_bits = 0; unsigned int offset = 0; int i; for (i = 0; i < sb->map_nr; i++) { unsigned long word = READ_ONCE(sb->map[i].word); unsigned long cleared = READ_ONCE(sb->map[i].cleared); unsigned int word_bits = __map_depth(sb, i); word &= ~cleared; while (word_bits > 0) { unsigned int bits = min(8 - byte_bits, word_bits); byte |= (word & (BIT(bits) - 1)) << byte_bits; byte_bits += bits; if (byte_bits == 8) { emit_byte(m, offset, byte); byte = 0; byte_bits = 0; offset++; } word >>= bits; word_bits -= bits; } } if (byte_bits) { emit_byte(m, offset, byte); offset++; } if (offset) seq_putc(m, '\n'); } EXPORT_SYMBOL_GPL(sbitmap_bitmap_show); static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq, unsigned int depth) { return clamp_t(unsigned int, min(depth, sbq->min_shallow_depth) / SBQ_WAIT_QUEUES, 1, SBQ_WAKE_BATCH); } int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, int shift, bool round_robin, gfp_t flags, int node) { int ret; int i; ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node, round_robin, true); if (ret) return ret; sbq->min_shallow_depth = UINT_MAX; sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); atomic_set(&sbq->wake_index, 0); atomic_set(&sbq->ws_active, 0); atomic_set(&sbq->completion_cnt, 0); atomic_set(&sbq->wakeup_cnt, 0); sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); if (!sbq->ws) { sbitmap_free(&sbq->sb); return -ENOMEM; } for (i = 0; i < SBQ_WAIT_QUEUES; i++) init_waitqueue_head(&sbq->ws[i].wait); return 0; } EXPORT_SYMBOL_GPL(sbitmap_queue_init_node); static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq, unsigned int depth) { unsigned int wake_batch; wake_batch = sbq_calc_wake_batch(sbq, depth); if (sbq->wake_batch != wake_batch) WRITE_ONCE(sbq->wake_batch, wake_batch); } void sbitmap_queue_recalculate_wake_batch(struct sbitmap_queue *sbq, unsigned int users) { unsigned int wake_batch; unsigned int depth = (sbq->sb.depth + users - 1) / users; wake_batch = clamp_val(depth / SBQ_WAIT_QUEUES, 1, SBQ_WAKE_BATCH); WRITE_ONCE(sbq->wake_batch, wake_batch); } EXPORT_SYMBOL_GPL(sbitmap_queue_recalculate_wake_batch);