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| author | Mike Travis <travis@sgi.com> | 2008-07-18 18:11:33 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-20 10:21:12 +0200 |
| commit | 80422d3431cc990b967da129f9eb8e3e9989f841 (patch) | |
| tree | 4c8424e7c22433caa39192e6273b7859545f7be1 /include/linux/cpumask.h | |
| parent | b38868aabeeb9c0c76a41ac5fa98c24bf0096f2a (diff) | |
| download | lwn-80422d3431cc990b967da129f9eb8e3e9989f841.tar.gz lwn-80422d3431cc990b967da129f9eb8e3e9989f841.zip | |
cpumask: Provide a generic set of CPUMASK_ALLOC macros, FIXUP
* Rename CPUMASK_VAR --> CPUMASK_PTR (and simplify)
* Fix a semantic error in CPUMASK_ALLOC
* Add a bit of commentry to cpumask.h
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/cpumask.h')
| -rw-r--r-- | include/linux/cpumask.h | 33 |
1 files changed, 26 insertions, 7 deletions
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 72f9c32c12b0..30d59d1d0626 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -75,16 +75,36 @@ * CPU_MASK_NONE Initializer - no bits set * unsigned long *cpus_addr(mask) Array of unsigned long's in mask * + * CPUMASK_ALLOC kmalloc's a structure that is a composite of many cpumask_t + * variables, and CPUMASK_PTR provides pointers to each field. + * + * The structure should be defined something like this: + * struct my_cpumasks { + * cpumask_t mask1; + * cpumask_t mask2; + * }; + * + * Usage is then: + * CPUMASK_ALLOC(my_cpumasks); + * CPUMASK_PTR(mask1, my_cpumasks); + * CPUMASK_PTR(mask2, my_cpumasks); + * + * --- DO NOT reference cpumask_t pointers until this check --- + * if (my_cpumasks == NULL) + * "kmalloc failed"... + * + * References are now pointers to the cpumask_t variables (*mask1, ...) + * *if NR_CPUS > BITS_PER_LONG * CPUMASK_ALLOC(m) Declares and allocates struct m *m = - * (struct m *)kmalloc(sizeof(*m), ...) - * CPUMASK_FREE(m) Macro for kfree(v) + * kmalloc(sizeof(*m), GFP_KERNEL) + * CPUMASK_FREE(m) Macro for kfree(m) *else * CPUMASK_ALLOC(m) Declares struct m _m, *m = &_m * CPUMASK_FREE(m) Nop *endif - * CPUMASK_VAR(v, m) Declares cpumask_t *v = - * m + offset(struct m, v) + * CPUMASK_PTR(v, m) Declares cpumask_t *v = &(m->v) + * ------------------------------------------------------------------------ * * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing * int cpumask_parse_user(ubuf, ulen, mask) Parse ascii string as cpumask @@ -326,11 +346,10 @@ extern cpumask_t cpu_mask_all; #define CPUMASK_ALLOC(m) struct m *m = kmalloc(sizeof(*m), GFP_KERNEL) #define CPUMASK_FREE(m) kfree(m) #else -#define CPUMASK_ALLOC(m) struct allmasks _m, *m = &_m +#define CPUMASK_ALLOC(m) struct m _m, *m = &_m #define CPUMASK_FREE(m) #endif -#define CPUMASK_VAR(v, m) cpumask_t *v = (cpumask_t *) \ - ((unsigned long)(m) + offsetof(struct m, v)) +#define CPUMASK_PTR(v, m) cpumask_t *v = &(m->v) #define cpumask_scnprintf(buf, len, src) \ __cpumask_scnprintf((buf), (len), &(src), NR_CPUS) |