1 // SPDX-License-Identifier: GPL-2.0
2 /* Manage affinity to optimize IPIs inside the kernel perf API. */
10 #include "affinity.h"
14 	int sz = cpu__max_cpu().cpu + 8 - 1;  in get_cpu_set_size()
24 int affinity__setup(struct affinity *a)  in affinity__setup()
28 	a->orig_cpus = bitmap_zalloc(cpu_set_size * 8);  in affinity__setup()
29 	if (!a->orig_cpus)  in affinity__setup()
30 		return -1;  in affinity__setup()
31 	sched_getaffinity(0, cpu_set_size, (cpu_set_t *)a->orig_cpus);  in affinity__setup()
32 	a->sched_cpus = bitmap_zalloc(cpu_set_size * 8);  in affinity__setup()
33 	if (!a->sched_cpus) {  in affinity__setup()
34 		zfree(&a->orig_cpus);  in affinity__setup()
35 		return -1;  in affinity__setup()
37 	bitmap_zero((unsigned long *)a->sched_cpus, cpu_set_size);  in affinity__setup()
38 	a->changed = false;  in affinity__setup()
44  * It is more efficient to change perf's affinity to the target
48 void affinity__set(struct affinity *a, int cpu)  in affinity__set()
54 	 * - if cpu is -1  in affinity__set()
55 	 * - restrict out of bound access to sched_cpus  in affinity__set()
57 	if (cpu == -1 || ((cpu >= (cpu_set_size * 8))))  in affinity__set()
60 	a->changed = true;  in affinity__set()
61 	__set_bit(cpu, a->sched_cpus);  in affinity__set()
63 	 * We ignore errors because affinity is just an optimization.  in affinity__set()
67 	sched_setaffinity(0, cpu_set_size, (cpu_set_t *)a->sched_cpus);  in affinity__set()
68 	__clear_bit(cpu, a->sched_cpus);  in affinity__set()
71 static void __affinity__cleanup(struct affinity *a)  in __affinity__cleanup()
75 	if (a->changed)  in __affinity__cleanup()
76 		sched_setaffinity(0, cpu_set_size, (cpu_set_t *)a->orig_cpus);  in __affinity__cleanup()
77 	zfree(&a->sched_cpus);  in __affinity__cleanup()
78 	zfree(&a->orig_cpus);  in __affinity__cleanup()
81 void affinity__cleanup(struct affinity *a)  in affinity__cleanup()