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c45c6ea2e5
This patch adds a -C option to stat, record, top to designate a list of CPUs to monitor. CPUs can be specified as a comma-separated list or ranges, no space allowed. Examples: $ perf record -a -C0-1,4-7 sleep 1 $ perf top -C0-4 $ perf stat -a -C1,2,3,4 sleep 1 With perf record in per-thread mode with inherit mode on, samples are collected only when the thread runs on the designated CPUs. The -C option does not turn on system-wide mode automatically. Cc: David S. Miller <davem@davemloft.net> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <4bff9496.d345d80a.41fe.7b00@mx.google.com> Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
115 lines
2.0 KiB
C
115 lines
2.0 KiB
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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static int read_all_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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int read_cpu_map(const char *cpu_list)
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{
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unsigned long start_cpu, end_cpu = 0;
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char *p = NULL;
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int i, nr_cpus = 0;
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if (!cpu_list)
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return read_all_cpu_map();
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if (!isdigit(*cpu_list))
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goto invalid;
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while (isdigit(*cpu_list)) {
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p = NULL;
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start_cpu = strtoul(cpu_list, &p, 0);
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if (start_cpu >= INT_MAX
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|| (*p != '\0' && *p != ',' && *p != '-'))
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goto invalid;
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if (*p == '-') {
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cpu_list = ++p;
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p = NULL;
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end_cpu = strtoul(cpu_list, &p, 0);
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if (end_cpu >= INT_MAX || (*p != '\0' && *p != ','))
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goto invalid;
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if (end_cpu < start_cpu)
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goto invalid;
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} else {
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end_cpu = start_cpu;
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}
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for (; start_cpu <= end_cpu; start_cpu++) {
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/* check for duplicates */
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for (i = 0; i < nr_cpus; i++)
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if (cpumap[i] == (int)start_cpu)
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goto invalid;
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assert(nr_cpus < MAX_NR_CPUS);
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cpumap[nr_cpus++] = (int)start_cpu;
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}
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if (*p)
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++p;
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cpu_list = p;
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}
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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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invalid:
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return -1;
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}
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