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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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C
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204// SPDX-License-Identifier: GPL-2.0
#include <linux/objpool.h>#include <linux/slab.h>#include <linux/vmalloc.h>#include <linux/atomic.h>#include <linux/irqflags.h>#include <linux/cpumask.h>#include <linux/log2.h>
/* * objpool: ring-array based lockless MPMC/FIFO queues * * Copyright: wuqiang.matt@bytedance.com,mhiramat@kernel.org */
/* initialize percpu objpool_slot */static intobjpool_init_percpu_slot(struct objpool_head *pool, struct objpool_slot *slot, int nodes, void *context, objpool_init_obj_cb objinit){ void *obj = (void *)&slot->entries[pool->capacity]; int i;
/* initialize elements of percpu objpool_slot */ slot->mask = pool->capacity - 1;
for (i = 0; i < nodes; i++) { if (objinit) { int rc = objinit(obj, context); if (rc) return rc; } slot->entries[slot->tail & slot->mask] = obj; obj = obj + pool->obj_size; slot->tail++; slot->last = slot->tail; pool->nr_objs++; }
return 0;}
/* allocate and initialize percpu slots */static intobjpool_init_percpu_slots(struct objpool_head *pool, int nr_objs, void *context, objpool_init_obj_cb objinit){ int i, cpu_count = 0;
for (i = 0; i < nr_cpu_ids; i++) {
struct objpool_slot *slot; int nodes, size, rc;
/* skip the cpu node which could never be present */ if (!cpu_possible(i)) continue;
/* compute how many objects to be allocated with this slot */ nodes = nr_objs / pool->nr_possible_cpus; if (cpu_count < (nr_objs % pool->nr_possible_cpus)) nodes++; cpu_count++;
size = struct_size(slot, entries, pool->capacity) + pool->obj_size * nodes;
/* * here we allocate percpu-slot & objs together in a single * allocation to make it more compact, taking advantage of * warm caches and TLB hits. in default vmalloc is used to * reduce the pressure of kernel slab system. as we know, * mimimal size of vmalloc is one page since vmalloc would * always align the requested size to page size. * but if vmalloc fails or it is not available (e.g. GFP_ATOMIC) * allocate percpu slot with kmalloc. */ slot = NULL;
if ((pool->gfp & (GFP_ATOMIC | GFP_KERNEL)) != GFP_ATOMIC) slot = __vmalloc_node(size, sizeof(void *), pool->gfp, cpu_to_node(i), __builtin_return_address(0));
if (!slot) { slot = kmalloc_node(size, pool->gfp, cpu_to_node(i)); if (!slot) return -ENOMEM; } memset(slot, 0, size); pool->cpu_slots[i] = slot;
/* initialize the objpool_slot of cpu node i */ rc = objpool_init_percpu_slot(pool, slot, nodes, context, objinit); if (rc) return rc; }
return 0;}
/* cleanup all percpu slots of the object pool */static void objpool_fini_percpu_slots(struct objpool_head *pool){ int i;
if (!pool->cpu_slots) return;
for (i = 0; i < nr_cpu_ids; i++) kvfree(pool->cpu_slots[i]); kfree(pool->cpu_slots);}
/* initialize object pool and pre-allocate objects */int objpool_init(struct objpool_head *pool, int nr_objs, int object_size, gfp_t gfp, void *context, objpool_init_obj_cb objinit, objpool_fini_cb release){ int rc, capacity, slot_size;
/* check input parameters */ if (nr_objs <= 0 || nr_objs > OBJPOOL_NR_OBJECT_MAX || object_size <= 0 || object_size > OBJPOOL_OBJECT_SIZE_MAX) return -EINVAL;
/* align up to unsigned long size */ object_size = ALIGN(object_size, sizeof(long));
/* calculate capacity of percpu objpool_slot */ capacity = roundup_pow_of_two(nr_objs); if (!capacity) return -EINVAL;
/* initialize objpool pool */ memset(pool, 0, sizeof(struct objpool_head)); pool->nr_possible_cpus = num_possible_cpus(); pool->obj_size = object_size; pool->capacity = capacity; pool->gfp = gfp & ~__GFP_ZERO; pool->context = context; pool->release = release; slot_size = nr_cpu_ids * sizeof(struct objpool_slot *); pool->cpu_slots = kzalloc(slot_size, pool->gfp); if (!pool->cpu_slots) return -ENOMEM;
/* initialize per-cpu slots */ rc = objpool_init_percpu_slots(pool, nr_objs, context, objinit); if (rc) objpool_fini_percpu_slots(pool); else refcount_set(&pool->ref, pool->nr_objs + 1);
return rc;}EXPORT_SYMBOL_GPL(objpool_init);
/* release whole objpool forcely */void objpool_free(struct objpool_head *pool){ if (!pool->cpu_slots) return;
/* release percpu slots */ objpool_fini_percpu_slots(pool);
/* call user's cleanup callback if provided */ if (pool->release) pool->release(pool, pool->context);}EXPORT_SYMBOL_GPL(objpool_free);
/* drop the allocated object, rather reclaim it to objpool */int objpool_drop(void *obj, struct objpool_head *pool){ if (!obj || !pool) return -EINVAL;
if (refcount_dec_and_test(&pool->ref)) { objpool_free(pool); return 0; }
return -EAGAIN;}EXPORT_SYMBOL_GPL(objpool_drop);
/* drop unused objects and defref objpool for releasing */void objpool_fini(struct objpool_head *pool){ int count = 1; /* extra ref for objpool itself */
/* drop all remained objects from objpool */ while (objpool_pop(pool)) count++;
if (refcount_sub_and_test(count, &pool->ref)) objpool_free(pool);}EXPORT_SYMBOL_GPL(objpool_fini);