The Cpuset API

Defines
#define	hwloc_cpuset_foreach_begin(cpu, set)
	Loop macro iterating on CPU set set.
#define	hwloc_cpuset_foreach_end()   }
	End of loop.
Typedefs
typedef struct hwloc_cpuset_s *	hwloc_cpuset_t
	Set of CPUs represented as an opaque pointer to an internal bitmask.
typedef struct hwloc_cpuset_s *	hwloc_const_cpuset_t
Functions
hwloc_cpuset_t	hwloc_cpuset_alloc (void)
	Allocate a new empty CPU set.
void	hwloc_cpuset_free (hwloc_cpuset_t set)
	Free CPU set set.
hwloc_cpuset_t	hwloc_cpuset_dup (hwloc_cpuset_t set)
	Duplicate CPU set set by allocating a new CPU set and copying its contents.
void	hwloc_cpuset_copy (hwloc_cpuset_t dst, hwloc_cpuset_t src)
	Copy the contents of CPU set src into the already allocated CPU set dst.
int	hwloc_cpuset_snprintf (char *restrict buf, size_t buflen, hwloc_const_cpuset_t set)
	Stringify a cpuset.
int	hwloc_cpuset_asprintf (char **strp, hwloc_const_cpuset_t set)
	Stringify a cpuset into a newly allocated string.
hwloc_cpuset_t	hwloc_cpuset_from_string (const char *restrict string)
	Parse a cpuset string.
void	hwloc_cpuset_zero (hwloc_cpuset_t set)
	Primitives & macros for building, modifying and consulting "sets" of cpus.
void	hwloc_cpuset_fill (hwloc_cpuset_t set)
	Fill CPU set set.
void	hwloc_cpuset_from_ulong (hwloc_cpuset_t set, unsigned long mask)
	Setup CPU set set from unsigned long mask.
void	hwloc_cpuset_from_ith_ulong (hwloc_cpuset_t set, int i, unsigned long mask)
	Setup CPU set set from unsigned long mask used as i -th subset.
unsigned long	hwloc_cpuset_to_ulong (hwloc_const_cpuset_t set)
	Convert the beginning part of CPU set set into unsigned long mask.
unsigned long	hwloc_cpuset_to_ith_ulong (hwloc_const_cpuset_t set, int i)
	Convert the i -th subset of CPU set set into unsigned long mask.
void	hwloc_cpuset_cpu (hwloc_cpuset_t set, unsigned cpu)
	Clear CPU set set and set CPU cpu.
void	hwloc_cpuset_all_but_cpu (hwloc_cpuset_t set, unsigned cpu)
	Clear CPU set set and set all but the CPU cpu.
void	hwloc_cpuset_set (hwloc_cpuset_t set, unsigned cpu)
	Add CPU cpu in CPU set set.
void	hwloc_cpuset_set_range (hwloc_cpuset_t set, unsigned begincpu, unsigned endcpu)
	Add CPUs from begincpu to endcpu in CPU set set.
void	hwloc_cpuset_clr (hwloc_cpuset_t set, unsigned cpu)
	Remove CPU cpu from CPU set set.
int	hwloc_cpuset_isset (hwloc_const_cpuset_t set, unsigned cpu)
	Test whether CPU cpu is part of set set.
int	hwloc_cpuset_iszero (hwloc_const_cpuset_t set)
	Test whether set set is zero.
int	hwloc_cpuset_isfull (hwloc_const_cpuset_t set)
	Test whether set set is full.
int	hwloc_cpuset_isequal (hwloc_const_cpuset_t set1, hwloc_const_cpuset_t set2)
	Test whether set set1 is equal to set set2.
int	hwloc_cpuset_intersects (hwloc_const_cpuset_t set1, hwloc_const_cpuset_t set2)
	Test whether sets set1 and set2 intersects.
int	hwloc_cpuset_isincluded (hwloc_const_cpuset_t sub_set, hwloc_const_cpuset_t super_set)
	Test whether set sub_set is part of set super_set.
void	hwloc_cpuset_orset (hwloc_cpuset_t set, hwloc_const_cpuset_t modifier_set)
	Or set modifier_set into set set.
void	hwloc_cpuset_andset (hwloc_cpuset_t set, hwloc_const_cpuset_t modifier_set)
	And set modifier_set into set set.
void	hwloc_cpuset_clearset (hwloc_cpuset_t set, hwloc_const_cpuset_t modifier_set)
	Clear set modifier_set out of set set.
void	hwloc_cpuset_xorset (hwloc_cpuset_t set, hwloc_const_cpuset_t modifier_set)
	Xor set set with set modifier_set.
int	hwloc_cpuset_first (hwloc_const_cpuset_t set)
	Compute the first CPU (least significant bit) in CPU set set.
int	hwloc_cpuset_last (hwloc_const_cpuset_t set)
	Compute the last CPU (most significant bit) in CPU set set.
void	hwloc_cpuset_singlify (hwloc_cpuset_t set)
	Keep a single CPU among those set in CPU set set.
int	hwloc_cpuset_compar_first (hwloc_const_cpuset_t set1, hwloc_const_cpuset_t set2)
	Compar CPU sets set1 and set2 using their first set bit.
int	hwloc_cpuset_compar (hwloc_const_cpuset_t set1, hwloc_const_cpuset_t set2)
	Compar CPU sets set1 and set2 using their last bits.
int	hwloc_cpuset_weight (hwloc_const_cpuset_t set)
	Compute the weight of CPU set set.

---

Detailed Description

For use in hwloc itself, a hwloc_cpuset_t represents a set of logical processors.

Note:

cpusets are indexed by OS logical processor number.

---

Define Documentation

#define hwloc_cpuset_foreach_begin	(	cpu,
		set		)

Value:

for (cpu = 0; cpu < HWLOC_NBMAXCPUS; cpu++) \
                if (hwloc_cpuset_isset(set, cpu)) {

Loop macro iterating on CPU set set.

It yields on each cpu that is member of the set. It uses variables set (the cpu set) and cpu (the loop variable)

 

#define hwloc_cpuset_foreach_end

(

)

}

End of loop.

See also:

hwloc_cpuset_foreach_begin

---

Typedef Documentation

typedef struct hwloc_cpuset_s* hwloc_const_cpuset_t

typedef struct hwloc_cpuset_s* hwloc_cpuset_t

Set of CPUs represented as an opaque pointer to an internal bitmask.

---

Function Documentation

void hwloc_cpuset_all_but_cpu	(	hwloc_cpuset_t	set,
		unsigned	cpu
	)

Clear CPU set set and set all but the CPU cpu.

hwloc_cpuset_t hwloc_cpuset_alloc

(

void

)

Allocate a new empty CPU set.

void hwloc_cpuset_andset	(	hwloc_cpuset_t	set,
		hwloc_const_cpuset_t	modifier_set
	)

And set modifier_set into set set.

int hwloc_cpuset_asprintf	(	char **	strp,
		hwloc_const_cpuset_t	set
	)

Stringify a cpuset into a newly allocated string.

Returns:

the number of character that were actually written (not including the ending \0).

void hwloc_cpuset_clearset	(	hwloc_cpuset_t	set,
		hwloc_const_cpuset_t	modifier_set
	)

Clear set modifier_set out of set set.

void hwloc_cpuset_clr	(	hwloc_cpuset_t	set,
		unsigned	cpu
	)

Remove CPU cpu from CPU set set.

int hwloc_cpuset_compar	(	hwloc_const_cpuset_t	set1,
		hwloc_const_cpuset_t	set2
	)

Compar CPU sets set1 and set2 using their last bits.

Higher most significant bit is higher. The empty CPU set is considered lower than anything.

int hwloc_cpuset_compar_first	(	hwloc_const_cpuset_t	set1,
		hwloc_const_cpuset_t	set2
	)

Compar CPU sets set1 and set2 using their first set bit.

Smaller least significant bit is smaller. The empty CPU set is considered higher than anything.

void hwloc_cpuset_copy	(	hwloc_cpuset_t	dst,
		hwloc_cpuset_t	src
	)

Copy the contents of CPU set src into the already allocated CPU set dst.

void hwloc_cpuset_cpu	(	hwloc_cpuset_t	set,
		unsigned	cpu
	)

Clear CPU set set and set CPU cpu.

hwloc_cpuset_t hwloc_cpuset_dup

(

hwloc_cpuset_t

set

)

Duplicate CPU set set by allocating a new CPU set and copying its contents.

void hwloc_cpuset_fill

(

hwloc_cpuset_t

set

)

Fill CPU set set.

int hwloc_cpuset_first

(

hwloc_const_cpuset_t

set

)

Compute the first CPU (least significant bit) in CPU set set.

void hwloc_cpuset_free

(

hwloc_cpuset_t

set

)

Free CPU set set.

void hwloc_cpuset_from_ith_ulong	(	hwloc_cpuset_t	set,
		int	i,
		unsigned long	mask
	)

Setup CPU set set from unsigned long mask used as i -th subset.

hwloc_cpuset_t hwloc_cpuset_from_string

(

const char *restrict

string

)

Parse a cpuset string.

Must start and end with a digit.

void hwloc_cpuset_from_ulong	(	hwloc_cpuset_t	set,
		unsigned long	mask
	)

Setup CPU set set from unsigned long mask.

int hwloc_cpuset_intersects	(	hwloc_const_cpuset_t	set1,
		hwloc_const_cpuset_t	set2
	)

Test whether sets set1 and set2 intersects.

int hwloc_cpuset_isequal	(	hwloc_const_cpuset_t	set1,
		hwloc_const_cpuset_t	set2
	)

Test whether set set1 is equal to set set2.

int hwloc_cpuset_isfull

(

hwloc_const_cpuset_t

set

)

Test whether set set is full.

int hwloc_cpuset_isincluded	(	hwloc_const_cpuset_t	sub_set,
		hwloc_const_cpuset_t	super_set
	)

Test whether set sub_set is part of set super_set.

int hwloc_cpuset_isset	(	hwloc_const_cpuset_t	set,
		unsigned	cpu
	)

Test whether CPU cpu is part of set set.

int hwloc_cpuset_iszero

(

hwloc_const_cpuset_t

set

)

Test whether set set is zero.

int hwloc_cpuset_last

(

hwloc_const_cpuset_t

set

)

Compute the last CPU (most significant bit) in CPU set set.

void hwloc_cpuset_orset	(	hwloc_cpuset_t	set,
		hwloc_const_cpuset_t	modifier_set
	)

Or set modifier_set into set set.

void hwloc_cpuset_set	(	hwloc_cpuset_t	set,
		unsigned	cpu
	)

Add CPU cpu in CPU set set.

void hwloc_cpuset_set_range	(	hwloc_cpuset_t	set,
		unsigned	begincpu,
		unsigned	endcpu
	)

Add CPUs from begincpu to endcpu in CPU set set.

void hwloc_cpuset_singlify

(

hwloc_cpuset_t

set

)

Keep a single CPU among those set in CPU set set.

Might be used before binding so that the process does not have a chance of migrating between multiple logical CPUs in the original mask.

int hwloc_cpuset_snprintf	(	char *restrict	buf,
		size_t	buflen,
		hwloc_const_cpuset_t	set
	)

Stringify a cpuset.

Up to buflen characters may be written in buffer buf.

Returns:

the number of character that were actually written if not truncating, or that would have been written (not including the ending \0).

unsigned long hwloc_cpuset_to_ith_ulong	(	hwloc_const_cpuset_t	set,
		int	i
	)

Convert the i -th subset of CPU set set into unsigned long mask.

unsigned long hwloc_cpuset_to_ulong

(

hwloc_const_cpuset_t

set

)

Convert the beginning part of CPU set set into unsigned long mask.

int hwloc_cpuset_weight

(

hwloc_const_cpuset_t

set

)

Compute the weight of CPU set set.

void hwloc_cpuset_xorset	(	hwloc_cpuset_t	set,
		hwloc_const_cpuset_t	modifier_set
	)

Xor set set with set modifier_set.

void hwloc_cpuset_zero

(

hwloc_cpuset_t

set

)

Primitives & macros for building, modifying and consulting "sets" of cpus.

Empty CPU set set