C++ KMEM_CACHE函数代码示例

/**
 * fscrypt_init() - Set up for fs encryption.
 */
static int __init fscrypt_init(void)
{
	/*
	 * Use an unbound workqueue to allow bios to be decrypted in parallel
	 * even when they happen to complete on the same CPU.  This sacrifices
	 * locality, but it's worthwhile since decryption is CPU-intensive.
	 *
	 * Also use a high-priority workqueue to prioritize decryption work,
	 * which blocks reads from completing, over regular application tasks.
	 */
	fscrypt_read_workqueue = alloc_workqueue("fscrypt_read_queue",
						 WQ_UNBOUND | WQ_HIGHPRI,
						 num_online_cpus());
	if (!fscrypt_read_workqueue)
		goto fail;

	fscrypt_ctx_cachep = KMEM_CACHE(fscrypt_ctx, SLAB_RECLAIM_ACCOUNT);
	if (!fscrypt_ctx_cachep)
		goto fail_free_queue;

	fscrypt_info_cachep = KMEM_CACHE(fscrypt_info, SLAB_RECLAIM_ACCOUNT);
	if (!fscrypt_info_cachep)
		goto fail_free_ctx;

	return 0;

fail_free_ctx:
	kmem_cache_destroy(fscrypt_ctx_cachep);
fail_free_queue:
	destroy_workqueue(fscrypt_read_workqueue);
fail:
	return -ENOMEM;
}

int __init ext4_init_pageio(void)
{
	io_page_cachep = KMEM_CACHE(ext4_io_page, SLAB_RECLAIM_ACCOUNT);
	if (io_page_cachep == NULL)
		return -ENOMEM;
	io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT);
	if (io_end_cachep == NULL) {
		kmem_cache_destroy(io_page_cachep);
		return -ENOMEM;
	}
	return 0;
}

int __init ext4_init_system_zone(void)
{
	ext4_system_zone_cachep = KMEM_CACHE(ext4_system_zone, 0);
	if (ext4_system_zone_cachep == NULL)
		return -ENOMEM;
	return 0;
}

int __init ext4_init_pageio(void)
{
	io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT);
	if (io_end_cachep == NULL)
		return -ENOMEM;
	return 0;
}

int __init ext4_init_pageio(void)
{
	int i;

	io_page_cachep = KMEM_CACHE(ext4_io_page, SLAB_RECLAIM_ACCOUNT);
	if (io_page_cachep == NULL)
		return -ENOMEM;
	io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT);
	if (io_end_cachep == NULL) {
		kmem_cache_destroy(io_page_cachep);
		return -ENOMEM;
	}
	for (i = 0; i < WQ_HASH_SZ; i++)
		init_waitqueue_head(&ioend_wq[i]);

	return 0;
}

static int __init dm_bio_prison_init(void)
{
	_cell_cache = KMEM_CACHE(dm_bio_prison_cell, 0);
	if (!_cell_cache)
		return -ENOMEM;

	return 0;
}

/**
 * ext4_init_crypto() - Set up for ext4 encryption.
 *
 * We only call this when we start accessing encrypted files, since it
 * results in memory getting allocated that wouldn't otherwise be used.
 *
 * Return: Zero on success, non-zero otherwise.
 */
int ext4_init_crypto(void)
{
	int i, res = -ENOMEM;

	mutex_lock(&crypto_init);
	if (ext4_read_workqueue)
		goto already_initialized;
	ext4_read_workqueue = alloc_workqueue("ext4_crypto", WQ_HIGHPRI, 0);
	if (!ext4_read_workqueue)
		goto fail;

	ext4_crypto_ctx_cachep = KMEM_CACHE(ext4_crypto_ctx,
					    SLAB_RECLAIM_ACCOUNT);
	if (!ext4_crypto_ctx_cachep)
		goto fail;

	ext4_crypt_info_cachep = KMEM_CACHE(ext4_crypt_info,
					    SLAB_RECLAIM_ACCOUNT);
	if (!ext4_crypt_info_cachep)
		goto fail;

	for (i = 0; i < num_prealloc_crypto_ctxs; i++) {
		struct ext4_crypto_ctx *ctx;

		ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS);
		if (!ctx) {
			res = -ENOMEM;
			goto fail;
		}
		list_add(&ctx->free_list, &ext4_free_crypto_ctxs);
	}

	ext4_bounce_page_pool =
		mempool_create_page_pool(num_prealloc_crypto_pages, 0);
	if (!ext4_bounce_page_pool) {
		res = -ENOMEM;
		goto fail;
	}
already_initialized:
	mutex_unlock(&crypto_init);
	return 0;
fail:
	ext4_exit_crypto();
	mutex_unlock(&crypto_init);
	return res;
}

int __init init_ext4_system_zone(void)
{
	ext4_system_zone_cachep = KMEM_CACHE(ext4_system_zone,
					     SLAB_RECLAIM_ACCOUNT);
	if (ext4_system_zone_cachep == NULL)
		return -ENOMEM;
	return 0;
}

int __init dm_kcopyd_init(void)
{
	_job_cache = KMEM_CACHE(kcopyd_job, 0);
	if (!_job_cache)
		return -ENOMEM;

	return 0;
}

/*
 * initialise the VMA and region record slabs
 */
void __init mmap_init(void)
{
	int ret;

	ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL);
	VM_BUG_ON(ret);
	vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC);
}

int __init dm_io_init(void)
{
	_dm_io_cache = KMEM_CACHE(io, 0);
	if (!_dm_io_cache)
		return -ENOMEM;

	return 0;
}

int kvm_async_pf_init(void)
{
	async_pf_cache = KMEM_CACHE(kvm_async_pf, 0);

	if (!async_pf_cache)
		return -ENOMEM;

	return 0;
}

int __init i915_global_context_init(void)
{
	global.slab_ce = KMEM_CACHE(intel_context, SLAB_HWCACHE_ALIGN);
	if (!global.slab_ce)
		return -ENOMEM;

	i915_global_register(&global.base);
	return 0;
}

static int __init iostash_init(void)
{
    int ret = -1, i;

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
	ERR("Kernel version < 2.6.28 not supported.");
	return -ENOENT;
#endif
	DBG("++ iostash_init() ++\n");

	memset(&gctx, 0, sizeof(gctx));
	do {
		gctx.io_pool = KMEM_CACHE(iostash_bio, 0);
		if (!gctx.io_pool) {
			ERR("iostash_init: KMEM_CACHE() failed\n");
			break;
		}

		gctx.io_client = dm_io_client_create();
		if (IS_ERR(gctx.io_client)) {
			ERR("iostash_init: dm_io_client() failed\n");
			break;
		}

		gctx.sce = sce_create();
		if (!gctx.sce) {
			ERR("iostash_init: sce_create() failed\n");
			break;
		}

		gctx.pdm = pdm_create(gctx.sce, poptask_read, poptask_write);

		if (_init_iostash_kobjects()) {
		    ERR("KOBJECT INIT FAILED!");
		    _destroy_iostash_kobjects();
		}

		mutex_init(&gctx.ctl_mtx);

		for (i = 0; i < IOSTASH_MAXHDD_BCKTS; ++i)
		    INIT_LIST_HEAD(&gctx.hddtbl.bucket[i]);

		for (i = 0; i < IOSTASH_MAXSSD_BCKTS; ++i)
		    INIT_LIST_HEAD(&gctx.ssdtbl.bucket[i]);

		ret = 0;

	} while (0);

	if (ret) {
		_free_resource();
	}

	DBG("-- iostash_init() returns = %d --\n", ret);
	return ret;
}

int ua_init(void)
{
	ua_cache = KMEM_CACHE(ua_entry, 0);
	if (!ua_cache) {
		eprintk("%s", "Failed to create ua cache\n");
		return -ENOMEM;
	}

	return 0;
}