bvec_alloc

函数名称：bvec_alloc

函数原型：struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, mempool_t *pool)

返回类型：struct bio_vec

参数：

类型	参数	名称
gfp_t	gfp_mask
int	nr
unsigned long *	idx
mempool_t *	pool

178

当:nr恒等于1

179

idx等于0

180

退出

181

当:nr == 2...4

182

idx等于1

183

退出

184

当:nr == 5...16

185

idx等于2

186

退出

187

当:nr == 17...64

188

idx等于3

189

退出

190

当:nr == 65...128

191

idx等于4

192

退出

193

当:nr == 129...BIO_MAX_PAGES

194

idx等于5

195

退出

196

默认

197

返回:NULL

204

如果idx恒等于BVEC_POOL_MAX则

205

fallback :

206

bvl等于mempool_alloc - allocate an element from a specific memory pool*@pool: pointer to the memory pool which was allocated via* mempool_create().*@gfp_mask: the usual allocation bitmask.* this function only sleeps if the alloc_fn() function sleeps or

207

否则

208

bvs等于bvec_slabs加idx

209

__gfp_mask等于gfp_mask按位与Caller can reclaim 按位或DOC: Reclaim modifiers* Reclaim modifiers* ~~~~~~~~~~~~~~~~~* %__GFP_IO can start physical IO.* %__GFP_FS can call down to the low-level FS. Clearing the flag avoids the* allocator recursing into the filesystem which might already be holding* locks.的值的反

216

__gfp_mask或等于__GFP_NOMEMALLOC按位或__GFP_NORETRY按位或DOC: Action modifiers* Action modifiers* ~~~~~~~~~~~~~~~~* %__GFP_NOWARN suppresses allocation failure reports.* %__GFP_COMP address compound page metadata.* %__GFP_ZERO returns a zeroed page on success.

222

bvl等于分配高速缓存区

223

如果此条件成立可能性小(为编译器优化)(!bvl && (gfp_mask & Caller can reclaim ))则

224

idx等于BVEC_POOL_MAX

225

转到:fallback

229

idx自加

230

返回:bvl

**调用者**
名称	描述
bio_alloc_bioset	_alloc_bioset - allocate a bio for I/O@gfp_mask: the GFP_ mask given to the slab allocator@nr_iovecs: number of iovecs to pre-allocate@bs: the bio_set to allocate from
bio_integrity_alloc	_integrity_alloc - Allocate integrity payload and attach it to bio@bio: bio to attach integrity metadata to@gfp_mask: Memory allocation mask@nr_vecs: Number of integrity metadata scatter-gather elements Description: This function prepares a bio for

源代码转换工具开放的插件接口	X
支持：c/c++/esqlc/java Oracle/Informix/Mysql 插件可实现：逻辑报告代码生成和批量转换代码

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