mirror of https://gitee.com/openkylin/linux.git
60 lines
1012 B
C
60 lines
1012 B
C
#include "util.h"
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#include "../perf.h"
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#include "cpumap.h"
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#include <assert.h>
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#include <stdio.h>
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int cpumap[MAX_NR_CPUS];
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static int default_cpu_map(void)
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{
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int nr_cpus, i;
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nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
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assert(nr_cpus <= MAX_NR_CPUS);
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assert((int)nr_cpus >= 0);
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for (i = 0; i < nr_cpus; ++i)
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cpumap[i] = i;
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return nr_cpus;
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}
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int read_cpu_map(void)
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{
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FILE *onlnf;
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int nr_cpus = 0;
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int n, cpu, prev;
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char sep;
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onlnf = fopen("/sys/devices/system/cpu/online", "r");
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if (!onlnf)
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return default_cpu_map();
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sep = 0;
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prev = -1;
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for (;;) {
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n = fscanf(onlnf, "%u%c", &cpu, &sep);
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if (n <= 0)
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break;
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if (prev >= 0) {
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assert(nr_cpus + cpu - prev - 1 < MAX_NR_CPUS);
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while (++prev < cpu)
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cpumap[nr_cpus++] = prev;
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}
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assert (nr_cpus < MAX_NR_CPUS);
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cpumap[nr_cpus++] = cpu;
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if (n == 2 && sep == '-')
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prev = cpu;
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else
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prev = -1;
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if (n == 1 || sep == '\n')
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break;
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}
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fclose(onlnf);
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if (nr_cpus > 0)
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return nr_cpus;
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return default_cpu_map();
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}
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