linux-stable/include/linux/nodemask.h
Paul Jackson 7ea931c9fc mempolicy: add bitmap_onto() and bitmap_fold() operations
The following adds two more bitmap operators, bitmap_onto() and bitmap_fold(),
with the usual cpumask and nodemask wrappers.

The bitmap_onto() operator computes one bitmap relative to another.  If the
n-th bit in the origin mask is set, then the m-th bit of the destination mask
will be set, where m is the position of the n-th set bit in the relative mask.

The bitmap_fold() operator folds a bitmap into a second that has bit m set iff
the input bitmap has some bit n set, where m == n mod sz, for the specified sz
value.

There are two substantive changes between this patch and its
predecessor bitmap_relative:
 1) Renamed bitmap_relative() to be bitmap_onto().
 2) Added bitmap_fold().

The essential motivation for bitmap_onto() is to provide a mechanism for
converting a cpuset-relative CPU or Node mask to an absolute mask.  Cpuset
relative masks are written as if the current task were in a cpuset whose CPUs
or Nodes were just the consecutive ones numbered 0..N-1, for some N.  The
bitmap_onto() operator is provided in anticipation of adding support for the
first such cpuset relative mask, by the mbind() and set_mempolicy() system
calls, using a planned flag of MPOL_F_RELATIVE_NODES.  These bitmap operators
(and their nodemask wrappers, in particular) will be used in code that
converts the user specified cpuset relative memory policy to a specific system
node numbered policy, given the current mems_allowed of the tasks cpuset.

Such cpuset relative mempolicies will address two deficiencies
of the existing interface between cpusets and mempolicies:
 1) A task cannot at present reliably establish a cpuset
    relative mempolicy because there is an essential race
    condition, in that the tasks cpuset may be changed in
    between the time the task can query its cpuset placement,
    and the time the task can issue the applicable mbind or
    set_memplicy system call.
 2) A task cannot at present establish what cpuset relative
    mempolicy it would like to have, if it is in a smaller
    cpuset than it might have mempolicy preferences for,
    because the existing interface only allows specifying
    mempolicies for nodes currently allowed by the cpuset.

Cpuset relative mempolicies are useful for tasks that don't distinguish
particularly between one CPU or Node and another, but only between how many of
each are allowed, and the proper placement of threads and memory pages on the
various CPUs and Nodes available.

The motivation for the added bitmap_fold() can be seen in the following
example.

Let's say an application has specified some mempolicies that presume 16 memory
nodes, including say a mempolicy that specified MPOL_F_RELATIVE_NODES (cpuset
relative) nodes 12-15.  Then lets say that application is crammed into a
cpuset that only has 8 memory nodes, 0-7.  If one just uses bitmap_onto(),
this mempolicy, mapped to that cpuset, would ignore the requested relative
nodes above 7, leaving it empty of nodes.  That's not good; better to fold the
higher nodes down, so that some nodes are included in the resulting mapped
mempolicy.  In this case, the mempolicy nodes 12-15 are taken modulo 8 (the
weight of the mems_allowed of the confining cpuset), resulting in a mempolicy
specifying nodes 4-7.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: <kosaki.motohiro@jp.fujitsu.com>
Cc: <ray-lk@madrabbit.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:19 -07:00

463 lines
14 KiB
C

#ifndef __LINUX_NODEMASK_H
#define __LINUX_NODEMASK_H
/*
* Nodemasks provide a bitmap suitable for representing the
* set of Node's in a system, one bit position per Node number.
*
* See detailed comments in the file linux/bitmap.h describing the
* data type on which these nodemasks are based.
*
* For details of nodemask_scnprintf() and nodemask_parse_user(),
* see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
* For details of nodelist_scnprintf() and nodelist_parse(), see
* bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
* For details of node_remap(), see bitmap_bitremap in lib/bitmap.c.
* For details of nodes_remap(), see bitmap_remap in lib/bitmap.c.
* For details of nodes_onto(), see bitmap_onto in lib/bitmap.c.
* For details of nodes_fold(), see bitmap_fold in lib/bitmap.c.
*
* The available nodemask operations are:
*
* void node_set(node, mask) turn on bit 'node' in mask
* void node_clear(node, mask) turn off bit 'node' in mask
* void nodes_setall(mask) set all bits
* void nodes_clear(mask) clear all bits
* int node_isset(node, mask) true iff bit 'node' set in mask
* int node_test_and_set(node, mask) test and set bit 'node' in mask
*
* void nodes_and(dst, src1, src2) dst = src1 & src2 [intersection]
* void nodes_or(dst, src1, src2) dst = src1 | src2 [union]
* void nodes_xor(dst, src1, src2) dst = src1 ^ src2
* void nodes_andnot(dst, src1, src2) dst = src1 & ~src2
* void nodes_complement(dst, src) dst = ~src
*
* int nodes_equal(mask1, mask2) Does mask1 == mask2?
* int nodes_intersects(mask1, mask2) Do mask1 and mask2 intersect?
* int nodes_subset(mask1, mask2) Is mask1 a subset of mask2?
* int nodes_empty(mask) Is mask empty (no bits sets)?
* int nodes_full(mask) Is mask full (all bits sets)?
* int nodes_weight(mask) Hamming weight - number of set bits
*
* void nodes_shift_right(dst, src, n) Shift right
* void nodes_shift_left(dst, src, n) Shift left
*
* int first_node(mask) Number lowest set bit, or MAX_NUMNODES
* int next_node(node, mask) Next node past 'node', or MAX_NUMNODES
* int first_unset_node(mask) First node not set in mask, or
* MAX_NUMNODES.
*
* nodemask_t nodemask_of_node(node) Return nodemask with bit 'node' set
* NODE_MASK_ALL Initializer - all bits set
* NODE_MASK_NONE Initializer - no bits set
* unsigned long *nodes_addr(mask) Array of unsigned long's in mask
*
* int nodemask_scnprintf(buf, len, mask) Format nodemask for printing
* int nodemask_parse_user(ubuf, ulen, mask) Parse ascii string as nodemask
* int nodelist_scnprintf(buf, len, mask) Format nodemask as list for printing
* int nodelist_parse(buf, map) Parse ascii string as nodelist
* int node_remap(oldbit, old, new) newbit = map(old, new)(oldbit)
* void nodes_remap(dst, src, old, new) *dst = map(old, new)(src)
* void nodes_onto(dst, orig, relmap) *dst = orig relative to relmap
* void nodes_fold(dst, orig, sz) dst bits = orig bits mod sz
*
* for_each_node_mask(node, mask) for-loop node over mask
*
* int num_online_nodes() Number of online Nodes
* int num_possible_nodes() Number of all possible Nodes
*
* int node_online(node) Is some node online?
* int node_possible(node) Is some node possible?
*
* int any_online_node(mask) First online node in mask
*
* node_set_online(node) set bit 'node' in node_online_map
* node_set_offline(node) clear bit 'node' in node_online_map
*
* for_each_node(node) for-loop node over node_possible_map
* for_each_online_node(node) for-loop node over node_online_map
*
* Subtlety:
* 1) The 'type-checked' form of node_isset() causes gcc (3.3.2, anyway)
* to generate slightly worse code. So use a simple one-line #define
* for node_isset(), instead of wrapping an inline inside a macro, the
* way we do the other calls.
*/
#include <linux/kernel.h>
#include <linux/threads.h>
#include <linux/bitmap.h>
#include <linux/numa.h>
typedef struct { DECLARE_BITMAP(bits, MAX_NUMNODES); } nodemask_t;
extern nodemask_t _unused_nodemask_arg_;
#define node_set(node, dst) __node_set((node), &(dst))
static inline void __node_set(int node, volatile nodemask_t *dstp)
{
set_bit(node, dstp->bits);
}
#define node_clear(node, dst) __node_clear((node), &(dst))
static inline void __node_clear(int node, volatile nodemask_t *dstp)
{
clear_bit(node, dstp->bits);
}
#define nodes_setall(dst) __nodes_setall(&(dst), MAX_NUMNODES)
static inline void __nodes_setall(nodemask_t *dstp, int nbits)
{
bitmap_fill(dstp->bits, nbits);
}
#define nodes_clear(dst) __nodes_clear(&(dst), MAX_NUMNODES)
static inline void __nodes_clear(nodemask_t *dstp, int nbits)
{
bitmap_zero(dstp->bits, nbits);
}
/* No static inline type checking - see Subtlety (1) above. */
#define node_isset(node, nodemask) test_bit((node), (nodemask).bits)
#define node_test_and_set(node, nodemask) \
__node_test_and_set((node), &(nodemask))
static inline int __node_test_and_set(int node, nodemask_t *addr)
{
return test_and_set_bit(node, addr->bits);
}
#define nodes_and(dst, src1, src2) \
__nodes_and(&(dst), &(src1), &(src2), MAX_NUMNODES)
static inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
const nodemask_t *src2p, int nbits)
{
bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
}
#define nodes_or(dst, src1, src2) \
__nodes_or(&(dst), &(src1), &(src2), MAX_NUMNODES)
static inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
const nodemask_t *src2p, int nbits)
{
bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
}
#define nodes_xor(dst, src1, src2) \
__nodes_xor(&(dst), &(src1), &(src2), MAX_NUMNODES)
static inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
const nodemask_t *src2p, int nbits)
{
bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
}
#define nodes_andnot(dst, src1, src2) \
__nodes_andnot(&(dst), &(src1), &(src2), MAX_NUMNODES)
static inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
const nodemask_t *src2p, int nbits)
{
bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
}
#define nodes_complement(dst, src) \
__nodes_complement(&(dst), &(src), MAX_NUMNODES)
static inline void __nodes_complement(nodemask_t *dstp,
const nodemask_t *srcp, int nbits)
{
bitmap_complement(dstp->bits, srcp->bits, nbits);
}
#define nodes_equal(src1, src2) \
__nodes_equal(&(src1), &(src2), MAX_NUMNODES)
static inline int __nodes_equal(const nodemask_t *src1p,
const nodemask_t *src2p, int nbits)
{
return bitmap_equal(src1p->bits, src2p->bits, nbits);
}
#define nodes_intersects(src1, src2) \
__nodes_intersects(&(src1), &(src2), MAX_NUMNODES)
static inline int __nodes_intersects(const nodemask_t *src1p,
const nodemask_t *src2p, int nbits)
{
return bitmap_intersects(src1p->bits, src2p->bits, nbits);
}
#define nodes_subset(src1, src2) \
__nodes_subset(&(src1), &(src2), MAX_NUMNODES)
static inline int __nodes_subset(const nodemask_t *src1p,
const nodemask_t *src2p, int nbits)
{
return bitmap_subset(src1p->bits, src2p->bits, nbits);
}
#define nodes_empty(src) __nodes_empty(&(src), MAX_NUMNODES)
static inline int __nodes_empty(const nodemask_t *srcp, int nbits)
{
return bitmap_empty(srcp->bits, nbits);
}
#define nodes_full(nodemask) __nodes_full(&(nodemask), MAX_NUMNODES)
static inline int __nodes_full(const nodemask_t *srcp, int nbits)
{
return bitmap_full(srcp->bits, nbits);
}
#define nodes_weight(nodemask) __nodes_weight(&(nodemask), MAX_NUMNODES)
static inline int __nodes_weight(const nodemask_t *srcp, int nbits)
{
return bitmap_weight(srcp->bits, nbits);
}
#define nodes_shift_right(dst, src, n) \
__nodes_shift_right(&(dst), &(src), (n), MAX_NUMNODES)
static inline void __nodes_shift_right(nodemask_t *dstp,
const nodemask_t *srcp, int n, int nbits)
{
bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
}
#define nodes_shift_left(dst, src, n) \
__nodes_shift_left(&(dst), &(src), (n), MAX_NUMNODES)
static inline void __nodes_shift_left(nodemask_t *dstp,
const nodemask_t *srcp, int n, int nbits)
{
bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
}
/* FIXME: better would be to fix all architectures to never return
> MAX_NUMNODES, then the silly min_ts could be dropped. */
#define first_node(src) __first_node(&(src))
static inline int __first_node(const nodemask_t *srcp)
{
return min_t(int, MAX_NUMNODES, find_first_bit(srcp->bits, MAX_NUMNODES));
}
#define next_node(n, src) __next_node((n), &(src))
static inline int __next_node(int n, const nodemask_t *srcp)
{
return min_t(int,MAX_NUMNODES,find_next_bit(srcp->bits, MAX_NUMNODES, n+1));
}
#define nodemask_of_node(node) \
({ \
typeof(_unused_nodemask_arg_) m; \
if (sizeof(m) == sizeof(unsigned long)) { \
m.bits[0] = 1UL<<(node); \
} else { \
nodes_clear(m); \
node_set((node), m); \
} \
m; \
})
#define first_unset_node(mask) __first_unset_node(&(mask))
static inline int __first_unset_node(const nodemask_t *maskp)
{
return min_t(int,MAX_NUMNODES,
find_first_zero_bit(maskp->bits, MAX_NUMNODES));
}
#define NODE_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(MAX_NUMNODES)
#if MAX_NUMNODES <= BITS_PER_LONG
#define NODE_MASK_ALL \
((nodemask_t) { { \
[BITS_TO_LONGS(MAX_NUMNODES)-1] = NODE_MASK_LAST_WORD \
} })
#else
#define NODE_MASK_ALL \
((nodemask_t) { { \
[0 ... BITS_TO_LONGS(MAX_NUMNODES)-2] = ~0UL, \
[BITS_TO_LONGS(MAX_NUMNODES)-1] = NODE_MASK_LAST_WORD \
} })
#endif
#define NODE_MASK_NONE \
((nodemask_t) { { \
[0 ... BITS_TO_LONGS(MAX_NUMNODES)-1] = 0UL \
} })
#define nodes_addr(src) ((src).bits)
#define nodemask_scnprintf(buf, len, src) \
__nodemask_scnprintf((buf), (len), &(src), MAX_NUMNODES)
static inline int __nodemask_scnprintf(char *buf, int len,
const nodemask_t *srcp, int nbits)
{
return bitmap_scnprintf(buf, len, srcp->bits, nbits);
}
#define nodemask_parse_user(ubuf, ulen, dst) \
__nodemask_parse_user((ubuf), (ulen), &(dst), MAX_NUMNODES)
static inline int __nodemask_parse_user(const char __user *buf, int len,
nodemask_t *dstp, int nbits)
{
return bitmap_parse_user(buf, len, dstp->bits, nbits);
}
#define nodelist_scnprintf(buf, len, src) \
__nodelist_scnprintf((buf), (len), &(src), MAX_NUMNODES)
static inline int __nodelist_scnprintf(char *buf, int len,
const nodemask_t *srcp, int nbits)
{
return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
}
#define nodelist_parse(buf, dst) __nodelist_parse((buf), &(dst), MAX_NUMNODES)
static inline int __nodelist_parse(const char *buf, nodemask_t *dstp, int nbits)
{
return bitmap_parselist(buf, dstp->bits, nbits);
}
#define node_remap(oldbit, old, new) \
__node_remap((oldbit), &(old), &(new), MAX_NUMNODES)
static inline int __node_remap(int oldbit,
const nodemask_t *oldp, const nodemask_t *newp, int nbits)
{
return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
}
#define nodes_remap(dst, src, old, new) \
__nodes_remap(&(dst), &(src), &(old), &(new), MAX_NUMNODES)
static inline void __nodes_remap(nodemask_t *dstp, const nodemask_t *srcp,
const nodemask_t *oldp, const nodemask_t *newp, int nbits)
{
bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
}
#define nodes_onto(dst, orig, relmap) \
__nodes_onto(&(dst), &(orig), &(relmap), MAX_NUMNODES)
static inline void __nodes_onto(nodemask_t *dstp, const nodemask_t *origp,
const nodemask_t *relmapp, int nbits)
{
bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
}
#define nodes_fold(dst, orig, sz) \
__nodes_fold(&(dst), &(orig), sz, MAX_NUMNODES)
static inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
int sz, int nbits)
{
bitmap_fold(dstp->bits, origp->bits, sz, nbits);
}
#if MAX_NUMNODES > 1
#define for_each_node_mask(node, mask) \
for ((node) = first_node(mask); \
(node) < MAX_NUMNODES; \
(node) = next_node((node), (mask)))
#else /* MAX_NUMNODES == 1 */
#define for_each_node_mask(node, mask) \
if (!nodes_empty(mask)) \
for ((node) = 0; (node) < 1; (node)++)
#endif /* MAX_NUMNODES */
/*
* Bitmasks that are kept for all the nodes.
*/
enum node_states {
N_POSSIBLE, /* The node could become online at some point */
N_ONLINE, /* The node is online */
N_NORMAL_MEMORY, /* The node has regular memory */
#ifdef CONFIG_HIGHMEM
N_HIGH_MEMORY, /* The node has regular or high memory */
#else
N_HIGH_MEMORY = N_NORMAL_MEMORY,
#endif
N_CPU, /* The node has one or more cpus */
NR_NODE_STATES
};
/*
* The following particular system nodemasks and operations
* on them manage all possible and online nodes.
*/
extern nodemask_t node_states[NR_NODE_STATES];
#if MAX_NUMNODES > 1
static inline int node_state(int node, enum node_states state)
{
return node_isset(node, node_states[state]);
}
static inline void node_set_state(int node, enum node_states state)
{
__node_set(node, &node_states[state]);
}
static inline void node_clear_state(int node, enum node_states state)
{
__node_clear(node, &node_states[state]);
}
static inline int num_node_state(enum node_states state)
{
return nodes_weight(node_states[state]);
}
#define for_each_node_state(__node, __state) \
for_each_node_mask((__node), node_states[__state])
#define first_online_node first_node(node_states[N_ONLINE])
#define next_online_node(nid) next_node((nid), node_states[N_ONLINE])
extern int nr_node_ids;
#else
static inline int node_state(int node, enum node_states state)
{
return node == 0;
}
static inline void node_set_state(int node, enum node_states state)
{
}
static inline void node_clear_state(int node, enum node_states state)
{
}
static inline int num_node_state(enum node_states state)
{
return 1;
}
#define for_each_node_state(node, __state) \
for ( (node) = 0; (node) == 0; (node) = 1)
#define first_online_node 0
#define next_online_node(nid) (MAX_NUMNODES)
#define nr_node_ids 1
#endif
#define node_online_map node_states[N_ONLINE]
#define node_possible_map node_states[N_POSSIBLE]
#define any_online_node(mask) \
({ \
int node; \
for_each_node_mask(node, (mask)) \
if (node_online(node)) \
break; \
node; \
})
#define num_online_nodes() num_node_state(N_ONLINE)
#define num_possible_nodes() num_node_state(N_POSSIBLE)
#define node_online(node) node_state((node), N_ONLINE)
#define node_possible(node) node_state((node), N_POSSIBLE)
#define node_set_online(node) node_set_state((node), N_ONLINE)
#define node_set_offline(node) node_clear_state((node), N_ONLINE)
#define for_each_node(node) for_each_node_state(node, N_POSSIBLE)
#define for_each_online_node(node) for_each_node_state(node, N_ONLINE)
#endif /* __LINUX_NODEMASK_H */