1 #ifndef __LINUX_NODEMASK_H
2 #define __LINUX_NODEMASK_H
3 
4 /*
5  * Nodemasks provide a bitmap suitable for representing the
6  * set of Node's in a system, one bit position per Node number.
7  *
8  * See detailed comments in the file linux/bitmap.h describing the
9  * data type on which these nodemasks are based.
10  *
11  * For details of nodemask_parse_user(), see bitmap_parse_user() in
12  * lib/bitmap.c.  For details of nodelist_parse(), see bitmap_parselist(),
13  * also in bitmap.c.  For details of node_remap(), see bitmap_bitremap in
14  * lib/bitmap.c.  For details of nodes_remap(), see bitmap_remap in
15  * lib/bitmap.c.  For details of nodes_onto(), see bitmap_onto in
16  * lib/bitmap.c.  For details of nodes_fold(), see bitmap_fold in
17  * lib/bitmap.c.
18  *
19  * The available nodemask operations are:
20  *
21  * void node_set(node, mask)		turn on bit 'node' in mask
22  * void node_clear(node, mask)		turn off bit 'node' in mask
23  * void nodes_setall(mask)		set all bits
24  * void nodes_clear(mask)		clear all bits
25  * int node_isset(node, mask)		true iff bit 'node' set in mask
26  * int node_test_and_set(node, mask)	test and set bit 'node' in mask
27  *
28  * void nodes_and(dst, src1, src2)	dst = src1 & src2  [intersection]
29  * void nodes_or(dst, src1, src2)	dst = src1 | src2  [union]
30  * void nodes_xor(dst, src1, src2)	dst = src1 ^ src2
31  * void nodes_andnot(dst, src1, src2)	dst = src1 & ~src2
32  * void nodes_complement(dst, src)	dst = ~src
33  *
34  * int nodes_equal(mask1, mask2)	Does mask1 == mask2?
35  * int nodes_intersects(mask1, mask2)	Do mask1 and mask2 intersect?
36  * int nodes_subset(mask1, mask2)	Is mask1 a subset of mask2?
37  * int nodes_empty(mask)		Is mask empty (no bits sets)?
38  * int nodes_full(mask)			Is mask full (all bits sets)?
39  * int nodes_weight(mask)		Hamming weight - number of set bits
40  *
41  * void nodes_shift_right(dst, src, n)	Shift right
42  * void nodes_shift_left(dst, src, n)	Shift left
43  *
44  * int first_node(mask)			Number lowest set bit, or MAX_NUMNODES
45  * int next_node(node, mask)		Next node past 'node', or MAX_NUMNODES
46  * int first_unset_node(mask)		First node not set in mask, or
47  *					MAX_NUMNODES.
48  *
49  * nodemask_t nodemask_of_node(node)	Return nodemask with bit 'node' set
50  * NODE_MASK_ALL			Initializer - all bits set
51  * NODE_MASK_NONE			Initializer - no bits set
52  * unsigned long *nodes_addr(mask)	Array of unsigned long's in mask
53  *
54  * int nodemask_parse_user(ubuf, ulen, mask)	Parse ascii string as nodemask
55  * int nodelist_parse(buf, map)		Parse ascii string as nodelist
56  * int node_remap(oldbit, old, new)	newbit = map(old, new)(oldbit)
57  * void nodes_remap(dst, src, old, new)	*dst = map(old, new)(src)
58  * void nodes_onto(dst, orig, relmap)	*dst = orig relative to relmap
59  * void nodes_fold(dst, orig, sz)	dst bits = orig bits mod sz
60  *
61  * for_each_node_mask(node, mask)	for-loop node over mask
62  *
63  * int num_online_nodes()		Number of online Nodes
64  * int num_possible_nodes()		Number of all possible Nodes
65  *
66  * int node_random(mask)		Random node with set bit in mask
67  *
68  * int node_online(node)		Is some node online?
69  * int node_possible(node)		Is some node possible?
70  *
71  * node_set_online(node)		set bit 'node' in node_online_map
72  * node_set_offline(node)		clear bit 'node' in node_online_map
73  *
74  * for_each_node(node)			for-loop node over node_possible_map
75  * for_each_online_node(node)		for-loop node over node_online_map
76  *
77  * Subtlety:
78  * 1) The 'type-checked' form of node_isset() causes gcc (3.3.2, anyway)
79  *    to generate slightly worse code.  So use a simple one-line #define
80  *    for node_isset(), instead of wrapping an inline inside a macro, the
81  *    way we do the other calls.
82  *
83  * NODEMASK_SCRATCH
84  * When doing above logical AND, OR, XOR, Remap operations the callers tend to
85  * need temporary nodemask_t's on the stack. But if NODES_SHIFT is large,
86  * nodemask_t's consume too much stack space.  NODEMASK_SCRATCH is a helper
87  * for such situations. See below and CPUMASK_ALLOC also.
88  */
89 
90 #include <linux/kernel.h>
91 #include <linux/threads.h>
92 #include <linux/bitmap.h>
93 #include <linux/numa.h>
94 
95 typedef struct { DECLARE_BITMAP(bits, MAX_NUMNODES); } nodemask_t;
96 extern nodemask_t _unused_nodemask_arg_;
97 
98 /**
99  * nodemask_pr_args - printf args to output a nodemask
100  * @maskp: nodemask to be printed
101  *
102  * Can be used to provide arguments for '%*pb[l]' when printing a nodemask.
103  */
104 #define nodemask_pr_args(maskp)		MAX_NUMNODES, (maskp)->bits
105 
106 /*
107  * The inline keyword gives the compiler room to decide to inline, or
108  * not inline a function as it sees best.  However, as these functions
109  * are called in both __init and non-__init functions, if they are not
110  * inlined we will end up with a section mis-match error (of the type of
111  * freeable items not being freed).  So we must use __always_inline here
112  * to fix the problem.  If other functions in the future also end up in
113  * this situation they will also need to be annotated as __always_inline
114  */
115 #define node_set(node, dst) __node_set((node), &(dst))
__node_set(int node,volatile nodemask_t * dstp)116 static __always_inline void __node_set(int node, volatile nodemask_t *dstp)
117 {
118 	set_bit(node, dstp->bits);
119 }
120 
121 #define node_clear(node, dst) __node_clear((node), &(dst))
__node_clear(int node,volatile nodemask_t * dstp)122 static inline void __node_clear(int node, volatile nodemask_t *dstp)
123 {
124 	clear_bit(node, dstp->bits);
125 }
126 
127 #define nodes_setall(dst) __nodes_setall(&(dst), MAX_NUMNODES)
__nodes_setall(nodemask_t * dstp,unsigned int nbits)128 static inline void __nodes_setall(nodemask_t *dstp, unsigned int nbits)
129 {
130 	bitmap_fill(dstp->bits, nbits);
131 }
132 
133 #define nodes_clear(dst) __nodes_clear(&(dst), MAX_NUMNODES)
__nodes_clear(nodemask_t * dstp,unsigned int nbits)134 static inline void __nodes_clear(nodemask_t *dstp, unsigned int nbits)
135 {
136 	bitmap_zero(dstp->bits, nbits);
137 }
138 
139 /* No static inline type checking - see Subtlety (1) above. */
140 #define node_isset(node, nodemask) test_bit((node), (nodemask).bits)
141 
142 #define node_test_and_set(node, nodemask) \
143 			__node_test_and_set((node), &(nodemask))
__node_test_and_set(int node,nodemask_t * addr)144 static inline int __node_test_and_set(int node, nodemask_t *addr)
145 {
146 	return test_and_set_bit(node, addr->bits);
147 }
148 
149 #define nodes_and(dst, src1, src2) \
150 			__nodes_and(&(dst), &(src1), &(src2), MAX_NUMNODES)
__nodes_and(nodemask_t * dstp,const nodemask_t * src1p,const nodemask_t * src2p,unsigned int nbits)151 static inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
152 					const nodemask_t *src2p, unsigned int nbits)
153 {
154 	bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
155 }
156 
157 #define nodes_or(dst, src1, src2) \
158 			__nodes_or(&(dst), &(src1), &(src2), MAX_NUMNODES)
__nodes_or(nodemask_t * dstp,const nodemask_t * src1p,const nodemask_t * src2p,unsigned int nbits)159 static inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
160 					const nodemask_t *src2p, unsigned int nbits)
161 {
162 	bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
163 }
164 
165 #define nodes_xor(dst, src1, src2) \
166 			__nodes_xor(&(dst), &(src1), &(src2), MAX_NUMNODES)
__nodes_xor(nodemask_t * dstp,const nodemask_t * src1p,const nodemask_t * src2p,unsigned int nbits)167 static inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
168 					const nodemask_t *src2p, unsigned int nbits)
169 {
170 	bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
171 }
172 
173 #define nodes_andnot(dst, src1, src2) \
174 			__nodes_andnot(&(dst), &(src1), &(src2), MAX_NUMNODES)
__nodes_andnot(nodemask_t * dstp,const nodemask_t * src1p,const nodemask_t * src2p,unsigned int nbits)175 static inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
176 					const nodemask_t *src2p, unsigned int nbits)
177 {
178 	bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
179 }
180 
181 #define nodes_complement(dst, src) \
182 			__nodes_complement(&(dst), &(src), MAX_NUMNODES)
__nodes_complement(nodemask_t * dstp,const nodemask_t * srcp,unsigned int nbits)183 static inline void __nodes_complement(nodemask_t *dstp,
184 					const nodemask_t *srcp, unsigned int nbits)
185 {
186 	bitmap_complement(dstp->bits, srcp->bits, nbits);
187 }
188 
189 #define nodes_equal(src1, src2) \
190 			__nodes_equal(&(src1), &(src2), MAX_NUMNODES)
__nodes_equal(const nodemask_t * src1p,const nodemask_t * src2p,unsigned int nbits)191 static inline int __nodes_equal(const nodemask_t *src1p,
192 					const nodemask_t *src2p, unsigned int nbits)
193 {
194 	return bitmap_equal(src1p->bits, src2p->bits, nbits);
195 }
196 
197 #define nodes_intersects(src1, src2) \
198 			__nodes_intersects(&(src1), &(src2), MAX_NUMNODES)
__nodes_intersects(const nodemask_t * src1p,const nodemask_t * src2p,unsigned int nbits)199 static inline int __nodes_intersects(const nodemask_t *src1p,
200 					const nodemask_t *src2p, unsigned int nbits)
201 {
202 	return bitmap_intersects(src1p->bits, src2p->bits, nbits);
203 }
204 
205 #define nodes_subset(src1, src2) \
206 			__nodes_subset(&(src1), &(src2), MAX_NUMNODES)
__nodes_subset(const nodemask_t * src1p,const nodemask_t * src2p,unsigned int nbits)207 static inline int __nodes_subset(const nodemask_t *src1p,
208 					const nodemask_t *src2p, unsigned int nbits)
209 {
210 	return bitmap_subset(src1p->bits, src2p->bits, nbits);
211 }
212 
213 #define nodes_empty(src) __nodes_empty(&(src), MAX_NUMNODES)
__nodes_empty(const nodemask_t * srcp,unsigned int nbits)214 static inline int __nodes_empty(const nodemask_t *srcp, unsigned int nbits)
215 {
216 	return bitmap_empty(srcp->bits, nbits);
217 }
218 
219 #define nodes_full(nodemask) __nodes_full(&(nodemask), MAX_NUMNODES)
__nodes_full(const nodemask_t * srcp,unsigned int nbits)220 static inline int __nodes_full(const nodemask_t *srcp, unsigned int nbits)
221 {
222 	return bitmap_full(srcp->bits, nbits);
223 }
224 
225 #define nodes_weight(nodemask) __nodes_weight(&(nodemask), MAX_NUMNODES)
__nodes_weight(const nodemask_t * srcp,unsigned int nbits)226 static inline int __nodes_weight(const nodemask_t *srcp, unsigned int nbits)
227 {
228 	return bitmap_weight(srcp->bits, nbits);
229 }
230 
231 #define nodes_shift_right(dst, src, n) \
232 			__nodes_shift_right(&(dst), &(src), (n), MAX_NUMNODES)
__nodes_shift_right(nodemask_t * dstp,const nodemask_t * srcp,int n,int nbits)233 static inline void __nodes_shift_right(nodemask_t *dstp,
234 					const nodemask_t *srcp, int n, int nbits)
235 {
236 	bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
237 }
238 
239 #define nodes_shift_left(dst, src, n) \
240 			__nodes_shift_left(&(dst), &(src), (n), MAX_NUMNODES)
__nodes_shift_left(nodemask_t * dstp,const nodemask_t * srcp,int n,int nbits)241 static inline void __nodes_shift_left(nodemask_t *dstp,
242 					const nodemask_t *srcp, int n, int nbits)
243 {
244 	bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
245 }
246 
247 /* FIXME: better would be to fix all architectures to never return
248           > MAX_NUMNODES, then the silly min_ts could be dropped. */
249 
250 #define first_node(src) __first_node(&(src))
__first_node(const nodemask_t * srcp)251 static inline int __first_node(const nodemask_t *srcp)
252 {
253 	return min_t(int, MAX_NUMNODES, find_first_bit(srcp->bits, MAX_NUMNODES));
254 }
255 
256 #define next_node(n, src) __next_node((n), &(src))
__next_node(int n,const nodemask_t * srcp)257 static inline int __next_node(int n, const nodemask_t *srcp)
258 {
259 	return min_t(int,MAX_NUMNODES,find_next_bit(srcp->bits, MAX_NUMNODES, n+1));
260 }
261 
init_nodemask_of_node(nodemask_t * mask,int node)262 static inline void init_nodemask_of_node(nodemask_t *mask, int node)
263 {
264 	nodes_clear(*mask);
265 	node_set(node, *mask);
266 }
267 
268 #define nodemask_of_node(node)						\
269 ({									\
270 	typeof(_unused_nodemask_arg_) m;				\
271 	if (sizeof(m) == sizeof(unsigned long)) {			\
272 		m.bits[0] = 1UL << (node);				\
273 	} else {							\
274 		init_nodemask_of_node(&m, (node));			\
275 	}								\
276 	m;								\
277 })
278 
279 #define first_unset_node(mask) __first_unset_node(&(mask))
__first_unset_node(const nodemask_t * maskp)280 static inline int __first_unset_node(const nodemask_t *maskp)
281 {
282 	return min_t(int,MAX_NUMNODES,
283 			find_first_zero_bit(maskp->bits, MAX_NUMNODES));
284 }
285 
286 #define NODE_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(MAX_NUMNODES)
287 
288 #if MAX_NUMNODES <= BITS_PER_LONG
289 
290 #define NODE_MASK_ALL							\
291 ((nodemask_t) { {							\
292 	[BITS_TO_LONGS(MAX_NUMNODES)-1] = NODE_MASK_LAST_WORD		\
293 } })
294 
295 #else
296 
297 #define NODE_MASK_ALL							\
298 ((nodemask_t) { {							\
299 	[0 ... BITS_TO_LONGS(MAX_NUMNODES)-2] = ~0UL,			\
300 	[BITS_TO_LONGS(MAX_NUMNODES)-1] = NODE_MASK_LAST_WORD		\
301 } })
302 
303 #endif
304 
305 #define NODE_MASK_NONE							\
306 ((nodemask_t) { {							\
307 	[0 ... BITS_TO_LONGS(MAX_NUMNODES)-1] =  0UL			\
308 } })
309 
310 #define nodes_addr(src) ((src).bits)
311 
312 #define nodemask_parse_user(ubuf, ulen, dst) \
313 		__nodemask_parse_user((ubuf), (ulen), &(dst), MAX_NUMNODES)
__nodemask_parse_user(const char __user * buf,int len,nodemask_t * dstp,int nbits)314 static inline int __nodemask_parse_user(const char __user *buf, int len,
315 					nodemask_t *dstp, int nbits)
316 {
317 	return bitmap_parse_user(buf, len, dstp->bits, nbits);
318 }
319 
320 #define nodelist_parse(buf, dst) __nodelist_parse((buf), &(dst), MAX_NUMNODES)
__nodelist_parse(const char * buf,nodemask_t * dstp,int nbits)321 static inline int __nodelist_parse(const char *buf, nodemask_t *dstp, int nbits)
322 {
323 	return bitmap_parselist(buf, dstp->bits, nbits);
324 }
325 
326 #define node_remap(oldbit, old, new) \
327 		__node_remap((oldbit), &(old), &(new), MAX_NUMNODES)
__node_remap(int oldbit,const nodemask_t * oldp,const nodemask_t * newp,int nbits)328 static inline int __node_remap(int oldbit,
329 		const nodemask_t *oldp, const nodemask_t *newp, int nbits)
330 {
331 	return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
332 }
333 
334 #define nodes_remap(dst, src, old, new) \
335 		__nodes_remap(&(dst), &(src), &(old), &(new), MAX_NUMNODES)
__nodes_remap(nodemask_t * dstp,const nodemask_t * srcp,const nodemask_t * oldp,const nodemask_t * newp,int nbits)336 static inline void __nodes_remap(nodemask_t *dstp, const nodemask_t *srcp,
337 		const nodemask_t *oldp, const nodemask_t *newp, int nbits)
338 {
339 	bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
340 }
341 
342 #define nodes_onto(dst, orig, relmap) \
343 		__nodes_onto(&(dst), &(orig), &(relmap), MAX_NUMNODES)
__nodes_onto(nodemask_t * dstp,const nodemask_t * origp,const nodemask_t * relmapp,int nbits)344 static inline void __nodes_onto(nodemask_t *dstp, const nodemask_t *origp,
345 		const nodemask_t *relmapp, int nbits)
346 {
347 	bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
348 }
349 
350 #define nodes_fold(dst, orig, sz) \
351 		__nodes_fold(&(dst), &(orig), sz, MAX_NUMNODES)
__nodes_fold(nodemask_t * dstp,const nodemask_t * origp,int sz,int nbits)352 static inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
353 		int sz, int nbits)
354 {
355 	bitmap_fold(dstp->bits, origp->bits, sz, nbits);
356 }
357 
358 #if MAX_NUMNODES > 1
359 #define for_each_node_mask(node, mask)			\
360 	for ((node) = first_node(mask);			\
361 		(node) < MAX_NUMNODES;			\
362 		(node) = next_node((node), (mask)))
363 #else /* MAX_NUMNODES == 1 */
364 #define for_each_node_mask(node, mask)			\
365 	if (!nodes_empty(mask))				\
366 		for ((node) = 0; (node) < 1; (node)++)
367 #endif /* MAX_NUMNODES */
368 
369 /*
370  * Bitmasks that are kept for all the nodes.
371  */
372 enum node_states {
373 	N_POSSIBLE,		/* The node could become online at some point */
374 	N_ONLINE,		/* The node is online */
375 	N_NORMAL_MEMORY,	/* The node has regular memory */
376 #ifdef CONFIG_HIGHMEM
377 	N_HIGH_MEMORY,		/* The node has regular or high memory */
378 #else
379 	N_HIGH_MEMORY = N_NORMAL_MEMORY,
380 #endif
381 #ifdef CONFIG_MOVABLE_NODE
382 	N_MEMORY,		/* The node has memory(regular, high, movable) */
383 #else
384 	N_MEMORY = N_HIGH_MEMORY,
385 #endif
386 	N_CPU,		/* The node has one or more cpus */
387 	NR_NODE_STATES
388 };
389 
390 /*
391  * The following particular system nodemasks and operations
392  * on them manage all possible and online nodes.
393  */
394 
395 extern nodemask_t node_states[NR_NODE_STATES];
396 
397 #if MAX_NUMNODES > 1
node_state(int node,enum node_states state)398 static inline int node_state(int node, enum node_states state)
399 {
400 	return node_isset(node, node_states[state]);
401 }
402 
node_set_state(int node,enum node_states state)403 static inline void node_set_state(int node, enum node_states state)
404 {
405 	__node_set(node, &node_states[state]);
406 }
407 
node_clear_state(int node,enum node_states state)408 static inline void node_clear_state(int node, enum node_states state)
409 {
410 	__node_clear(node, &node_states[state]);
411 }
412 
num_node_state(enum node_states state)413 static inline int num_node_state(enum node_states state)
414 {
415 	return nodes_weight(node_states[state]);
416 }
417 
418 #define for_each_node_state(__node, __state) \
419 	for_each_node_mask((__node), node_states[__state])
420 
421 #define first_online_node	first_node(node_states[N_ONLINE])
422 #define first_memory_node	first_node(node_states[N_MEMORY])
next_online_node(int nid)423 static inline int next_online_node(int nid)
424 {
425 	return next_node(nid, node_states[N_ONLINE]);
426 }
next_memory_node(int nid)427 static inline int next_memory_node(int nid)
428 {
429 	return next_node(nid, node_states[N_MEMORY]);
430 }
431 
432 extern int nr_node_ids;
433 extern int nr_online_nodes;
434 
node_set_online(int nid)435 static inline void node_set_online(int nid)
436 {
437 	node_set_state(nid, N_ONLINE);
438 	nr_online_nodes = num_node_state(N_ONLINE);
439 }
440 
node_set_offline(int nid)441 static inline void node_set_offline(int nid)
442 {
443 	node_clear_state(nid, N_ONLINE);
444 	nr_online_nodes = num_node_state(N_ONLINE);
445 }
446 
447 #else
448 
node_state(int node,enum node_states state)449 static inline int node_state(int node, enum node_states state)
450 {
451 	return node == 0;
452 }
453 
node_set_state(int node,enum node_states state)454 static inline void node_set_state(int node, enum node_states state)
455 {
456 }
457 
node_clear_state(int node,enum node_states state)458 static inline void node_clear_state(int node, enum node_states state)
459 {
460 }
461 
num_node_state(enum node_states state)462 static inline int num_node_state(enum node_states state)
463 {
464 	return 1;
465 }
466 
467 #define for_each_node_state(node, __state) \
468 	for ( (node) = 0; (node) == 0; (node) = 1)
469 
470 #define first_online_node	0
471 #define first_memory_node	0
472 #define next_online_node(nid)	(MAX_NUMNODES)
473 #define nr_node_ids		1
474 #define nr_online_nodes		1
475 
476 #define node_set_online(node)	   node_set_state((node), N_ONLINE)
477 #define node_set_offline(node)	   node_clear_state((node), N_ONLINE)
478 
479 #endif
480 
481 #if defined(CONFIG_NUMA) && (MAX_NUMNODES > 1)
482 extern int node_random(const nodemask_t *maskp);
483 #else
node_random(const nodemask_t * mask)484 static inline int node_random(const nodemask_t *mask)
485 {
486 	return 0;
487 }
488 #endif
489 
490 #define node_online_map 	node_states[N_ONLINE]
491 #define node_possible_map 	node_states[N_POSSIBLE]
492 
493 #define num_online_nodes()	num_node_state(N_ONLINE)
494 #define num_possible_nodes()	num_node_state(N_POSSIBLE)
495 #define node_online(node)	node_state((node), N_ONLINE)
496 #define node_possible(node)	node_state((node), N_POSSIBLE)
497 
498 #define for_each_node(node)	   for_each_node_state(node, N_POSSIBLE)
499 #define for_each_online_node(node) for_each_node_state(node, N_ONLINE)
500 
501 /*
502  * For nodemask scrach area.
503  * NODEMASK_ALLOC(type, name) allocates an object with a specified type and
504  * name.
505  */
506 #if NODES_SHIFT > 8 /* nodemask_t > 256 bytes */
507 #define NODEMASK_ALLOC(type, name, gfp_flags)	\
508 			type *name = kmalloc(sizeof(*name), gfp_flags)
509 #define NODEMASK_FREE(m)			kfree(m)
510 #else
511 #define NODEMASK_ALLOC(type, name, gfp_flags)	type _##name, *name = &_##name
512 #define NODEMASK_FREE(m)			do {} while (0)
513 #endif
514 
515 /* A example struture for using NODEMASK_ALLOC, used in mempolicy. */
516 struct nodemask_scratch {
517 	nodemask_t	mask1;
518 	nodemask_t	mask2;
519 };
520 
521 #define NODEMASK_SCRATCH(x)						\
522 			NODEMASK_ALLOC(struct nodemask_scratch, x,	\
523 					GFP_KERNEL | __GFP_NORETRY)
524 #define NODEMASK_SCRATCH_FREE(x)	NODEMASK_FREE(x)
525 
526 
527 #endif /* __LINUX_NODEMASK_H */
528