1 // SPDX-License-Identifier: GPL-2.0
2 /* Manage affinity to optimize IPIs inside the kernel perf API. */
11 #include "affinity.h"
15 	int sz = cpu__max_cpu().cpu + 8 - 1;  in get_cpu_set_size()
25 int affinity__setup(struct affinity *a)  in affinity__setup()
29 	a->orig_cpus = bitmap_zalloc(cpu_set_size * 8);  in affinity__setup()
30 	if (!a->orig_cpus)  in affinity__setup()
31 		return -1;  in affinity__setup()
32 	sched_getaffinity(0, cpu_set_size, (cpu_set_t *)a->orig_cpus);  in affinity__setup()
33 	a->sched_cpus = bitmap_zalloc(cpu_set_size * 8);  in affinity__setup()
34 	if (!a->sched_cpus) {  in affinity__setup()
35 		zfree(&a->orig_cpus);  in affinity__setup()
36 		return -1;  in affinity__setup()
38 	bitmap_zero((unsigned long *)a->sched_cpus, cpu_set_size);  in affinity__setup()
39 	a->changed = false;  in affinity__setup()
45  * It is more efficient to change perf's affinity to the target
49 void affinity__set(struct affinity *a, int cpu)  in affinity__set()
55 	 * - if cpu is -1  in affinity__set()
56 	 * - restrict out of bound access to sched_cpus  in affinity__set()
58 	if (cpu == -1 || ((cpu >= (cpu_set_size * 8))))  in affinity__set()
61 	a->changed = true;  in affinity__set()
62 	__set_bit(cpu, a->sched_cpus);  in affinity__set()
64 	 * We ignore errors because affinity is just an optimization.  in affinity__set()
68 	sched_setaffinity(0, cpu_set_size, (cpu_set_t *)a->sched_cpus);  in affinity__set()
69 	__clear_bit(cpu, a->sched_cpus);  in affinity__set()
72 static void __affinity__cleanup(struct affinity *a)  in __affinity__cleanup()
76 	if (a->changed)  in __affinity__cleanup()
77 		sched_setaffinity(0, cpu_set_size, (cpu_set_t *)a->orig_cpus);  in __affinity__cleanup()
78 	zfree(&a->sched_cpus);  in __affinity__cleanup()
79 	zfree(&a->orig_cpus);  in __affinity__cleanup()
82 void affinity__cleanup(struct affinity *a)  in affinity__cleanup()