^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) lru_cache.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) Copyright (C) 2003-2008, LINBIT Information Technologies GmbH.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) Copyright (C) 2003-2008, Philipp Reisner <philipp.reisner@linbit.com>.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) Copyright (C) 2003-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/string.h> /* for memset */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/seq_file.h> /* for seq_printf */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/lru_cache.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) MODULE_AUTHOR("Philipp Reisner <phil@linbit.com>, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) "Lars Ellenberg <lars@linbit.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) MODULE_DESCRIPTION("lru_cache - Track sets of hot objects");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) /* this is developers aid only.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * it catches concurrent access (lack of locking on the users part) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #define PARANOIA_ENTRY() do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) BUG_ON(!lc); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) BUG_ON(!lc->nr_elements); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) BUG_ON(test_and_set_bit(__LC_PARANOIA, &lc->flags)); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #define RETURN(x...) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) clear_bit_unlock(__LC_PARANOIA, &lc->flags); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) return x ; } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) /* BUG() if e is not one of the elements tracked by lc */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #define PARANOIA_LC_ELEMENT(lc, e) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) struct lru_cache *lc_ = (lc); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) struct lc_element *e_ = (e); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) unsigned i = e_->lc_index; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) BUG_ON(i >= lc_->nr_elements); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) BUG_ON(lc_->lc_element[i] != e_); } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) /* We need to atomically
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * - try to grab the lock (set LC_LOCKED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * - only if there is no pending transaction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * (neither LC_DIRTY nor LC_STARVING is set)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * Because of PARANOIA_ENTRY() above abusing lc->flags as well,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * it is not sufficient to just say
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) * return 0 == cmpxchg(&lc->flags, 0, LC_LOCKED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) int lc_try_lock(struct lru_cache *lc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) unsigned long val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) val = cmpxchg(&lc->flags, 0, LC_LOCKED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) } while (unlikely (val == LC_PARANOIA));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) /* Spin until no-one is inside a PARANOIA_ENTRY()/RETURN() section. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) return 0 == val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) #if 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) /* Alternative approach, spin in case someone enters or leaves a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * PARANOIA_ENTRY()/RETURN() section. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) unsigned long old, new, val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) old = lc->flags & LC_PARANOIA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) new = old | LC_LOCKED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) val = cmpxchg(&lc->flags, old, new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) } while (unlikely (val == (old ^ LC_PARANOIA)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) return old == val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * lc_create - prepares to track objects in an active set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * @name: descriptive name only used in lc_seq_printf_stats and lc_seq_dump_details
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * @max_pending_changes: maximum changes to accumulate until a transaction is required
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * @e_count: number of elements allowed to be active simultaneously
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * @e_size: size of the tracked objects
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * @e_off: offset to the &struct lc_element member in a tracked object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * Returns a pointer to a newly initialized struct lru_cache on success,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * or NULL on (allocation) failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) struct lru_cache *lc_create(const char *name, struct kmem_cache *cache,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) unsigned max_pending_changes,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) unsigned e_count, size_t e_size, size_t e_off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) struct hlist_head *slot = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) struct lc_element **element = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) struct lru_cache *lc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) struct lc_element *e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) unsigned cache_obj_size = kmem_cache_size(cache);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) unsigned i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) WARN_ON(cache_obj_size < e_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (cache_obj_size < e_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) /* e_count too big; would probably fail the allocation below anyways.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * for typical use cases, e_count should be few thousand at most. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) if (e_count > LC_MAX_ACTIVE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) slot = kcalloc(e_count, sizeof(struct hlist_head), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) if (!slot)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) element = kcalloc(e_count, sizeof(struct lc_element *), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (!element)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) lc = kzalloc(sizeof(*lc), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) if (!lc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) INIT_LIST_HEAD(&lc->in_use);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) INIT_LIST_HEAD(&lc->lru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) INIT_LIST_HEAD(&lc->free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) INIT_LIST_HEAD(&lc->to_be_changed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) lc->name = name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) lc->element_size = e_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) lc->element_off = e_off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) lc->nr_elements = e_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) lc->max_pending_changes = max_pending_changes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) lc->lc_cache = cache;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) lc->lc_element = element;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) lc->lc_slot = slot;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) /* preallocate all objects */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) for (i = 0; i < e_count; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) void *p = kmem_cache_alloc(cache, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (!p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) memset(p, 0, lc->element_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) e = p + e_off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) e->lc_index = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) e->lc_number = LC_FREE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) e->lc_new_number = LC_FREE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) list_add(&e->list, &lc->free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) element[i] = e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) if (i == e_count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) return lc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) /* else: could not allocate all elements, give up */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) for (i--; i; i--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) void *p = element[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) kmem_cache_free(cache, p - e_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) kfree(lc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) out_fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) kfree(element);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) kfree(slot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) static void lc_free_by_index(struct lru_cache *lc, unsigned i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) void *p = lc->lc_element[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) WARN_ON(!p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) if (p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) p -= lc->element_off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) kmem_cache_free(lc->lc_cache, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) * lc_destroy - frees memory allocated by lc_create()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) * @lc: the lru cache to destroy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) void lc_destroy(struct lru_cache *lc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) unsigned i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) if (!lc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) for (i = 0; i < lc->nr_elements; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) lc_free_by_index(lc, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) kfree(lc->lc_element);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) kfree(lc->lc_slot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) kfree(lc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) * lc_reset - does a full reset for @lc and the hash table slots.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) * It is roughly the equivalent of re-allocating a fresh lru_cache object,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) * basically a short cut to lc_destroy(lc); lc = lc_create(...);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) void lc_reset(struct lru_cache *lc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) unsigned i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) INIT_LIST_HEAD(&lc->in_use);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) INIT_LIST_HEAD(&lc->lru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) INIT_LIST_HEAD(&lc->free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) INIT_LIST_HEAD(&lc->to_be_changed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) lc->used = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) lc->hits = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) lc->misses = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) lc->starving = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) lc->locked = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) lc->changed = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) lc->pending_changes = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) lc->flags = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) memset(lc->lc_slot, 0, sizeof(struct hlist_head) * lc->nr_elements);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) for (i = 0; i < lc->nr_elements; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) struct lc_element *e = lc->lc_element[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) void *p = e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) p -= lc->element_off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) memset(p, 0, lc->element_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) /* re-init it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) e->lc_index = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) e->lc_number = LC_FREE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) e->lc_new_number = LC_FREE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) list_add(&e->list, &lc->free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) * lc_seq_printf_stats - print stats about @lc into @seq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) * @seq: the seq_file to print into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) * @lc: the lru cache to print statistics of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) void lc_seq_printf_stats(struct seq_file *seq, struct lru_cache *lc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) /* NOTE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) * total calls to lc_get are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) * (starving + hits + misses)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) * misses include "locked" count (update from an other thread in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) * progress) and "changed", when this in fact lead to an successful
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) * update of the cache.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) seq_printf(seq, "\t%s: used:%u/%u hits:%lu misses:%lu starving:%lu locked:%lu changed:%lu\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) lc->name, lc->used, lc->nr_elements,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) lc->hits, lc->misses, lc->starving, lc->locked, lc->changed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) static struct hlist_head *lc_hash_slot(struct lru_cache *lc, unsigned int enr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) return lc->lc_slot + (enr % lc->nr_elements);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) static struct lc_element *__lc_find(struct lru_cache *lc, unsigned int enr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) bool include_changing)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) struct lc_element *e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) BUG_ON(!lc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) BUG_ON(!lc->nr_elements);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) hlist_for_each_entry(e, lc_hash_slot(lc, enr), colision) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) /* "about to be changed" elements, pending transaction commit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) * are hashed by their "new number". "Normal" elements have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) * lc_number == lc_new_number. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) if (e->lc_new_number != enr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) if (e->lc_new_number == e->lc_number || include_changing)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) return e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) * lc_find - find element by label, if present in the hash table
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) * @lc: The lru_cache object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) * @enr: element number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) * Returns the pointer to an element, if the element with the requested
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) * "label" or element number is present in the hash table,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * or NULL if not found. Does not change the refcnt.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) * Ignores elements that are "about to be used", i.e. not yet in the active
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) * set, but still pending transaction commit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) struct lc_element *lc_find(struct lru_cache *lc, unsigned int enr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) return __lc_find(lc, enr, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) * lc_is_used - find element by label
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) * @lc: The lru_cache object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * @enr: element number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * Returns true, if the element with the requested "label" or element number is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * present in the hash table, and is used (refcnt > 0).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * Also finds elements that are not _currently_ used but only "about to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) * used", i.e. on the "to_be_changed" list, pending transaction commit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) bool lc_is_used(struct lru_cache *lc, unsigned int enr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) struct lc_element *e = __lc_find(lc, enr, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) return e && e->refcnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * lc_del - removes an element from the cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * @lc: The lru_cache object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) * @e: The element to remove
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) * @e must be unused (refcnt == 0). Moves @e from "lru" to "free" list,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) * sets @e->enr to %LC_FREE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) void lc_del(struct lru_cache *lc, struct lc_element *e)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) PARANOIA_ENTRY();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) PARANOIA_LC_ELEMENT(lc, e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) BUG_ON(e->refcnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) e->lc_number = e->lc_new_number = LC_FREE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) hlist_del_init(&e->colision);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) list_move(&e->list, &lc->free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) RETURN();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) static struct lc_element *lc_prepare_for_change(struct lru_cache *lc, unsigned new_number)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) struct list_head *n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) struct lc_element *e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) if (!list_empty(&lc->free))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) n = lc->free.next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) else if (!list_empty(&lc->lru))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) n = lc->lru.prev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) e = list_entry(n, struct lc_element, list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) PARANOIA_LC_ELEMENT(lc, e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) e->lc_new_number = new_number;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) if (!hlist_unhashed(&e->colision))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) __hlist_del(&e->colision);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) hlist_add_head(&e->colision, lc_hash_slot(lc, new_number));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) list_move(&e->list, &lc->to_be_changed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) return e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) static int lc_unused_element_available(struct lru_cache *lc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) if (!list_empty(&lc->free))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) return 1; /* something on the free list */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) if (!list_empty(&lc->lru))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) return 1; /* something to evict */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) /* used as internal flags to __lc_get */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) enum {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) LC_GET_MAY_CHANGE = 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) LC_GET_MAY_USE_UNCOMMITTED = 2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) static struct lc_element *__lc_get(struct lru_cache *lc, unsigned int enr, unsigned int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) struct lc_element *e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) PARANOIA_ENTRY();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) if (lc->flags & LC_STARVING) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) ++lc->starving;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) RETURN(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) e = __lc_find(lc, enr, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) /* if lc_new_number != lc_number,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) * this enr is currently being pulled in already,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) * and will be available once the pending transaction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) * has been committed. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) if (e) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) if (e->lc_new_number != e->lc_number) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) /* It has been found above, but on the "to_be_changed"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) * list, not yet committed. Don't pull it in twice,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) * wait for the transaction, then try again...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) if (!(flags & LC_GET_MAY_USE_UNCOMMITTED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) RETURN(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) /* ... unless the caller is aware of the implications,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) * probably preparing a cumulative transaction. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) ++e->refcnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) ++lc->hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) RETURN(e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) /* else: lc_new_number == lc_number; a real hit. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) ++lc->hits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) if (e->refcnt++ == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) lc->used++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) list_move(&e->list, &lc->in_use); /* Not evictable... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) RETURN(e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) /* e == NULL */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) ++lc->misses;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) if (!(flags & LC_GET_MAY_CHANGE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) RETURN(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) /* To avoid races with lc_try_lock(), first, mark us dirty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) * (using test_and_set_bit, as it implies memory barriers), ... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) test_and_set_bit(__LC_DIRTY, &lc->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) /* ... only then check if it is locked anyways. If lc_unlock clears
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * the dirty bit again, that's not a problem, we will come here again.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) if (test_bit(__LC_LOCKED, &lc->flags)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) ++lc->locked;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) RETURN(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) /* In case there is nothing available and we can not kick out
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * the LRU element, we have to wait ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) if (!lc_unused_element_available(lc)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) __set_bit(__LC_STARVING, &lc->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) RETURN(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) /* It was not present in the active set. We are going to recycle an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) * unused (or even "free") element, but we won't accumulate more than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) * max_pending_changes changes. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) if (lc->pending_changes >= lc->max_pending_changes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) RETURN(NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) e = lc_prepare_for_change(lc, enr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) BUG_ON(!e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) clear_bit(__LC_STARVING, &lc->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) BUG_ON(++e->refcnt != 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) lc->used++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) lc->pending_changes++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) RETURN(e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) * lc_get - get element by label, maybe change the active set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) * @enr: the label to look up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * Finds an element in the cache, increases its usage count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * "touches" and returns it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) * In case the requested number is not present, it needs to be added to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) * cache. Therefore it is possible that an other element becomes evicted from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) * the cache. In either case, the user is notified so he is able to e.g. keep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) * a persistent log of the cache changes, and therefore the objects in use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) * Return values:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) * NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) * The cache was marked %LC_STARVING,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) * or the requested label was not in the active set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) * and a changing transaction is still pending (@lc was marked %LC_DIRTY).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) * Or no unused or free element could be recycled (@lc will be marked as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) * %LC_STARVING, blocking further lc_get() operations).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) * pointer to the element with the REQUESTED element number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) * In this case, it can be used right away
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) * pointer to an UNUSED element with some different element number,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) * where that different number may also be %LC_FREE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) * In this case, the cache is marked %LC_DIRTY,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) * so lc_try_lock() will no longer succeed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) * The returned element pointer is moved to the "to_be_changed" list,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) * and registered with the new element number on the hash collision chains,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) * so it is possible to pick it up from lc_is_used().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) * Up to "max_pending_changes" (see lc_create()) can be accumulated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) * The user now should do whatever housekeeping is necessary,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) * typically serialize on lc_try_lock_for_transaction(), then call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) * lc_committed(lc) and lc_unlock(), to finish the change.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) * NOTE: The user needs to check the lc_number on EACH use, so he recognizes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) * any cache set change.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) struct lc_element *lc_get(struct lru_cache *lc, unsigned int enr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) return __lc_get(lc, enr, LC_GET_MAY_CHANGE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) * lc_get_cumulative - like lc_get; also finds to-be-changed elements
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) * @enr: the label to look up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) * Unlike lc_get this also returns the element for @enr, if it is belonging to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) * a pending transaction, so the return values are like for lc_get(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) * plus:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) * pointer to an element already on the "to_be_changed" list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) * In this case, the cache was already marked %LC_DIRTY.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) * Caller needs to make sure that the pending transaction is completed,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) * before proceeding to actually use this element.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) struct lc_element *lc_get_cumulative(struct lru_cache *lc, unsigned int enr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) return __lc_get(lc, enr, LC_GET_MAY_CHANGE|LC_GET_MAY_USE_UNCOMMITTED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) * lc_try_get - get element by label, if present; do not change the active set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) * @enr: the label to look up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) * Finds an element in the cache, increases its usage count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) * "touches" and returns it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) * Return values:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) * NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) * The cache was marked %LC_STARVING,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) * or the requested label was not in the active set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) * pointer to the element with the REQUESTED element number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) * In this case, it can be used right away
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) struct lc_element *lc_try_get(struct lru_cache *lc, unsigned int enr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) return __lc_get(lc, enr, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) * lc_committed - tell @lc that pending changes have been recorded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) * User is expected to serialize on explicit lc_try_lock_for_transaction()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) * before the transaction is started, and later needs to lc_unlock() explicitly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) * as well.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) void lc_committed(struct lru_cache *lc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) struct lc_element *e, *tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) PARANOIA_ENTRY();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) list_for_each_entry_safe(e, tmp, &lc->to_be_changed, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) /* count number of changes, not number of transactions */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) ++lc->changed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) e->lc_number = e->lc_new_number;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) list_move(&e->list, &lc->in_use);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) lc->pending_changes = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) RETURN();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) * lc_put - give up refcnt of @e
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) * @e: the element to put
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) * If refcnt reaches zero, the element is moved to the lru list,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) * and a %LC_STARVING (if set) is cleared.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) * Returns the new (post-decrement) refcnt.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) unsigned int lc_put(struct lru_cache *lc, struct lc_element *e)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) PARANOIA_ENTRY();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) PARANOIA_LC_ELEMENT(lc, e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) BUG_ON(e->refcnt == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) BUG_ON(e->lc_number != e->lc_new_number);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) if (--e->refcnt == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) /* move it to the front of LRU. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) list_move(&e->list, &lc->lru);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) lc->used--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) clear_bit_unlock(__LC_STARVING, &lc->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) RETURN(e->refcnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) * lc_element_by_index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) * @i: the index of the element to return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) struct lc_element *lc_element_by_index(struct lru_cache *lc, unsigned i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) BUG_ON(i >= lc->nr_elements);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) BUG_ON(lc->lc_element[i] == NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) BUG_ON(lc->lc_element[i]->lc_index != i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) return lc->lc_element[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) * lc_index_of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) * @e: the element to query for its index position in lc->element
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) unsigned int lc_index_of(struct lru_cache *lc, struct lc_element *e)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) PARANOIA_LC_ELEMENT(lc, e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) return e->lc_index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) * lc_set - associate index with label
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) * @enr: the label to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) * @index: the element index to associate label with.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) * Used to initialize the active set to some previously recorded state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) void lc_set(struct lru_cache *lc, unsigned int enr, int index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) struct lc_element *e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) struct list_head *lh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) if (index < 0 || index >= lc->nr_elements)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) e = lc_element_by_index(lc, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) BUG_ON(e->lc_number != e->lc_new_number);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) BUG_ON(e->refcnt != 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) e->lc_number = e->lc_new_number = enr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) hlist_del_init(&e->colision);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) if (enr == LC_FREE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) lh = &lc->free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) hlist_add_head(&e->colision, lc_hash_slot(lc, enr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) lh = &lc->lru;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) list_move(&e->list, lh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) * lc_dump - Dump a complete LRU cache to seq in textual form.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) * @lc: the lru cache to operate on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) * @seq: the &struct seq_file pointer to seq_printf into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) * @utext: user supplied additional "heading" or other info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) * @detail: function pointer the user may provide to dump further details
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) * of the object the lc_element is embedded in. May be NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) * Note: a leading space ' ' and trailing newline '\n' is implied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) void lc_seq_dump_details(struct seq_file *seq, struct lru_cache *lc, char *utext,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) void (*detail) (struct seq_file *, struct lc_element *))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) unsigned int nr_elements = lc->nr_elements;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) struct lc_element *e;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) seq_printf(seq, "\tnn: lc_number (new nr) refcnt %s\n ", utext);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) for (i = 0; i < nr_elements; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) e = lc_element_by_index(lc, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) if (e->lc_number != e->lc_new_number)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) seq_printf(seq, "\t%5d: %6d %8d %6d ",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) i, e->lc_number, e->lc_new_number, e->refcnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) seq_printf(seq, "\t%5d: %6d %-8s %6d ",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) i, e->lc_number, "-\"-", e->refcnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) if (detail)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) detail(seq, e);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) seq_putc(seq, '\n');
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) EXPORT_SYMBOL(lc_create);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) EXPORT_SYMBOL(lc_reset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) EXPORT_SYMBOL(lc_destroy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) EXPORT_SYMBOL(lc_set);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) EXPORT_SYMBOL(lc_del);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) EXPORT_SYMBOL(lc_try_get);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) EXPORT_SYMBOL(lc_find);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) EXPORT_SYMBOL(lc_get);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) EXPORT_SYMBOL(lc_put);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) EXPORT_SYMBOL(lc_committed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) EXPORT_SYMBOL(lc_element_by_index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) EXPORT_SYMBOL(lc_index_of);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) EXPORT_SYMBOL(lc_seq_printf_stats);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) EXPORT_SYMBOL(lc_seq_dump_details);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) EXPORT_SYMBOL(lc_try_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) EXPORT_SYMBOL(lc_is_used);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) EXPORT_SYMBOL(lc_get_cumulative);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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