<sched.h>: Add sched_getcpu() and cpu_set_t
This adds the cpu_set_t type definition and related functions and macros used to handle CPU thread affinity. sched_getcpu() sched_setaffinity() sched_getaffinity() Change-Id: If382ecafde8926341a88478062b275553645065b
This commit is contained in:
David 'Digit' Turner
@@ -73,6 +73,162 @@ extern int sched_rr_get_interval(pid_t pid, struct timespec *tp);
|
||||
extern int clone(int (*fn)(void *), void *child_stack, int flags, void* arg, ...);
|
||||
#endif
|
||||
|
||||
/* Support for cpu thread affinity */
|
||||
#ifdef _GNU_SOURCE
|
||||
|
||||
extern int sched_getcpu(void);
|
||||
|
||||
|
||||
/* Our implementation supports up to 32 independent CPUs, which is also
|
||||
* the maximum supported by the kernel at the moment. GLibc uses 1024 by
|
||||
* default.
|
||||
*
|
||||
* If you want to use more than that, you should use CPU_ALLOC() / CPU_FREE()
|
||||
* and the CPU_XXX_S() macro variants.
|
||||
*/
|
||||
#define CPU_SETSIZE 32
|
||||
|
||||
#define __CPU_BITTYPE unsigned long int /* mandated by the kernel */
|
||||
#define __CPU_BITSHIFT 5 /* should be log2(BITTYPE) */
|
||||
#define __CPU_BITS (1 << __CPU_BITSHIFT)
|
||||
#define __CPU_ELT(x) ((x) >> __CPU_BITSHIFT)
|
||||
#define __CPU_MASK(x) ((__CPU_BITTYPE)1 << ((x) & (__CPU_BITS-1)))
|
||||
|
||||
typedef struct {
|
||||
__CPU_BITTYPE __bits[ CPU_SETSIZE / __CPU_BITS ];
|
||||
} cpu_set_t;
|
||||
|
||||
extern int sched_setaffinity(pid_t pid, size_t setsize, const cpu_set_t* set);
|
||||
|
||||
extern int sched_getaffinity(pid_t pid, size_t setsize, cpu_set_t* set);
|
||||
|
||||
/* Provide optimized implementation for 32-bit cpu_set_t */
|
||||
#if CPU_SETSIZE == __CPU_BITS
|
||||
|
||||
# define CPU_ZERO(set_) \
|
||||
do{ \
|
||||
(set_)->__bits[0] = 0; \
|
||||
}while(0)
|
||||
|
||||
# define CPU_SET(cpu_,set_) \
|
||||
do {\
|
||||
size_t __cpu = (cpu_); \
|
||||
if (__cpu < CPU_SETSIZE) \
|
||||
(set_)->__bits[0] |= __CPU_MASK(__cpu); \
|
||||
}while (0)
|
||||
|
||||
# define CPU_CLR(cpu_,set_) \
|
||||
do {\
|
||||
size_t __cpu = (cpu_); \
|
||||
if (__cpu < CPU_SETSIZE) \
|
||||
(set_)->__bits[0] &= ~__CPU_MASK(__cpu); \
|
||||
}while (0)
|
||||
|
||||
# define CPU_ISSET(cpu_, set_) \
|
||||
(__extension__({\
|
||||
size_t __cpu = (cpu_); \
|
||||
(cpu_ < CPU_SETSIZE) \
|
||||
? ((set_)->__bits[0] & __CPU_MASK(__cpu)) != 0 \
|
||||
: 0; \
|
||||
}))
|
||||
|
||||
# define CPU_EQUAL(set1_, set2_) \
|
||||
((set1_)->__bits[0] == (set2_)->__bits[0])
|
||||
|
||||
# define __CPU_OP(dst_, set1_, set2_, op_) \
|
||||
do { \
|
||||
(dst_)->__bits[0] = (set1_)->__bits[0] op_ (set2_)->__bits[0]; \
|
||||
} while (0)
|
||||
|
||||
# define CPU_COUNT(set_) __builtin_popcountl((set_)->__bits[0])
|
||||
|
||||
#else /* CPU_SETSIZE != __CPU_BITS */
|
||||
|
||||
# define CPU_ZERO(set_) CPU_ZERO_S(sizeof(cpu_set_t), set_)
|
||||
# define CPU_SET(cpu_,set_) CPU_SET_S(cpu_,sizeof(cpu_set_t),set_)
|
||||
# define CPU_CLR(cpu_,set_) CPU_CLR_S(cpu_,sizeof(cpu_set_t),set_)
|
||||
# define CPU_ISSET(cpu_,set_) CPU_ISSET_S(cpu_,sizeof(cpu_set_t),set_)
|
||||
# define CPU_COUNT(set_) CPU_COUNT_S(sizeof(cpu_set_t),set_)
|
||||
# define CPU_EQUAL(set1_,set2_) CPU_EQUAL_S(sizeof(cpu_set_t),set1_,set2_)
|
||||
|
||||
# define __CPU_OP(dst_,set1_,set2_,op_) __CPU_OP_S(sizeof(cpu_set_t),dst_,set1_,set2_,op_)
|
||||
|
||||
#endif /* CPU_SETSIZE != __CPU_BITS */
|
||||
|
||||
#define CPU_AND(set1_,set2_) __CPU_OP(set1_,set2_,&)
|
||||
#define CPU_OR(set1_,set2_) __CPU_OP(set1_,set2_,|)
|
||||
#define CPU_XOR(set1_,set2_) __CPU_OP(set1_,set2_,^)
|
||||
|
||||
/* Support for dynamically-allocated cpu_set_t */
|
||||
|
||||
#define CPU_ALLOC_SIZE(count) \
|
||||
__CPU_ELT((count) + (__CPU_BITS-1))*sizeof(__CPU_BITTYPE)
|
||||
|
||||
#define CPU_ALLOC(count) __sched_cpualloc((count));
|
||||
#define CPU_FREE(set) __sched_cpufree((set))
|
||||
|
||||
extern cpu_set_t* __sched_cpualloc(size_t count);
|
||||
extern void __sched_cpufree(cpu_set_t* set);
|
||||
|
||||
#define CPU_ZERO_S(setsize_,set_) \
|
||||
do { \
|
||||
size_t __nn = 0; \
|
||||
size_t __nn_max = (setsize_)/sizeof(__CPU_BITTYPE); \
|
||||
for (; __nn < __nn_max; __nn++) \
|
||||
(set_)->__bits[__nn] = 0; \
|
||||
} while (0)
|
||||
|
||||
#define CPU_SET_S(cpu_,setsize_,set_) \
|
||||
do { \
|
||||
size_t __cpu = (cpu_); \
|
||||
if (__cpu < 8*(setsize_)) \
|
||||
(set_)->__bits[__CPU_ELT(__cpu)] |= __CPU_MASK(__cpu); \
|
||||
} while (0)
|
||||
|
||||
#define CPU_CLR_S(cpu_,setsize_,set_) \
|
||||
do { \
|
||||
size_t __cpu = (cpu_); \
|
||||
if (__cpu < 8*(setsize_)) \
|
||||
(set_)->__bits[__CPU_ELT(__cpu)] &= ~__CPU_MASK(__cpu); \
|
||||
} while (0)
|
||||
|
||||
#define CPU_ISSET_S(cpu_, setsize_, set_) \
|
||||
(__extension__ ({ \
|
||||
size_t __cpu = (cpu_); \
|
||||
(__cpu < 8*(setsize_)) \
|
||||
? ((set_)->__bits[__CPU_ELT(__cpu)] & __CPU_MASK(__cpu)) != 0 \
|
||||
: 0; \
|
||||
}))
|
||||
|
||||
#define CPU_EQUAL_S(setsize_, set1_, set2_) \
|
||||
(__extension__ ({ \
|
||||
__const __CPU_BITTYPE* __src1 = (set1_)->__bits; \
|
||||
__const __CPU_BITTYPE* __src2 = (set2_)->__bits; \
|
||||
size_t __nn = 0, __nn_max = (setsize_)/sizeof(__CPU_BITTYPE); \
|
||||
for (; __nn < __nn_max; __nn++) { \
|
||||
if (__src1[__nn] != __src2[__nn]) \
|
||||
break; \
|
||||
} \
|
||||
__nn == __nn_max; \
|
||||
}))
|
||||
|
||||
#define __CPU_OP_S(setsize_, dstset_, srcset1_, srcset2_, op) \
|
||||
do { \
|
||||
cpu_set_t* __dst = (dstset); \
|
||||
const __CPU_BITTYPE* __src1 = (srcset1)->__bits; \
|
||||
const __CPU_BITTYPE* __src2 = (srcset2)->__bits; \
|
||||
size_t __nn = 0, __nn_max = (setsize_)/sizeof(__CPU_BITTYPE); \
|
||||
for (; __nn < __nn_max; __nn++) \
|
||||
(__dst)->__bits[__nn] = __src1[__nn] op __src2[__nn]; \
|
||||
} while (0)
|
||||
|
||||
#define CPU_COUNT_S(setsize_, set_) \
|
||||
__sched_cpucount((setsize_), (set_))
|
||||
|
||||
extern int __sched_cpucount(size_t setsize, cpu_set_t* set);
|
||||
|
||||
#endif /* _GNU_SOURCE */
|
||||
|
||||
__END_DECLS
|
||||
|
||||
#endif /* _SCHED_H_ */
|
||||
|
||||
Reference in New Issue
Block a user