perf evsel: Fix use of inherit
perf stat doesn't mmap and its perfectly fine for it to use task-bound counters with inheritance. So set the attr.inherit on the caller and leave the syscall itself to validate it. When the mmap fails perf_evlist__mmap will just emit a warning if this is the failure reason. Reported-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic 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> Link: http://lkml.kernel.org/r/20110414170121.GC3229@ghostprotocols.net Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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@ -163,6 +163,7 @@ static void config_attr(struct perf_evsel *evsel, struct perf_evlist *evlist)
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struct perf_event_attr *attr = &evsel->attr;
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int track = !evsel->idx; /* only the first counter needs these */
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attr->inherit = !no_inherit;
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attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
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PERF_FORMAT_TOTAL_TIME_RUNNING |
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PERF_FORMAT_ID;
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@ -251,6 +252,9 @@ static void open_counters(struct perf_evlist *evlist)
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{
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struct perf_evsel *pos;
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if (evlist->cpus->map[0] < 0)
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no_inherit = true;
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list_for_each_entry(pos, &evlist->entries, node) {
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struct perf_event_attr *attr = &pos->attr;
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/*
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@ -271,8 +275,7 @@ static void open_counters(struct perf_evlist *evlist)
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retry_sample_id:
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attr->sample_id_all = sample_id_all_avail ? 1 : 0;
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try_again:
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if (perf_evsel__open(pos, evlist->cpus, evlist->threads, group,
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!no_inherit) < 0) {
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if (perf_evsel__open(pos, evlist->cpus, evlist->threads, group) < 0) {
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int err = errno;
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if (err == EPERM || err == EACCES) {
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@ -167,16 +167,17 @@ static int create_perf_stat_counter(struct perf_evsel *evsel)
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attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
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PERF_FORMAT_TOTAL_TIME_RUNNING;
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if (system_wide)
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return perf_evsel__open_per_cpu(evsel, evsel_list->cpus, false, false);
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attr->inherit = !no_inherit;
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if (system_wide)
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return perf_evsel__open_per_cpu(evsel, evsel_list->cpus, false);
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if (target_pid == -1 && target_tid == -1) {
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attr->disabled = 1;
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attr->enable_on_exec = 1;
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}
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return perf_evsel__open_per_thread(evsel, evsel_list->threads, false, false);
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return perf_evsel__open_per_thread(evsel, evsel_list->threads, false);
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}
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/*
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@ -290,7 +290,7 @@ static int test__open_syscall_event(void)
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goto out_thread_map_delete;
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}
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if (perf_evsel__open_per_thread(evsel, threads, false, false) < 0) {
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if (perf_evsel__open_per_thread(evsel, threads, false) < 0) {
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pr_debug("failed to open counter: %s, "
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"tweak /proc/sys/kernel/perf_event_paranoid?\n",
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strerror(errno));
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@ -303,7 +303,7 @@ static int test__open_syscall_event(void)
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}
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if (perf_evsel__read_on_cpu(evsel, 0, 0) < 0) {
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pr_debug("perf_evsel__open_read_on_cpu\n");
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pr_debug("perf_evsel__read_on_cpu\n");
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goto out_close_fd;
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}
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@ -365,7 +365,7 @@ static int test__open_syscall_event_on_all_cpus(void)
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goto out_thread_map_delete;
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}
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if (perf_evsel__open(evsel, cpus, threads, false, false) < 0) {
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if (perf_evsel__open(evsel, cpus, threads, false) < 0) {
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pr_debug("failed to open counter: %s, "
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"tweak /proc/sys/kernel/perf_event_paranoid?\n",
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strerror(errno));
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@ -418,7 +418,7 @@ static int test__open_syscall_event_on_all_cpus(void)
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continue;
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if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
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pr_debug("perf_evsel__open_read_on_cpu\n");
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pr_debug("perf_evsel__read_on_cpu\n");
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err = -1;
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break;
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}
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@ -529,7 +529,7 @@ static int test__basic_mmap(void)
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perf_evlist__add(evlist, evsels[i]);
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if (perf_evsel__open(evsels[i], cpus, threads, false, false) < 0) {
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if (perf_evsel__open(evsels[i], cpus, threads, false) < 0) {
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pr_debug("failed to open counter: %s, "
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"tweak /proc/sys/kernel/perf_event_paranoid?\n",
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strerror(errno));
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@ -845,9 +845,10 @@ static void start_counters(struct perf_evlist *evlist)
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}
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attr->mmap = 1;
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attr->inherit = inherit;
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try_again:
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if (perf_evsel__open(counter, top.evlist->cpus,
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top.evlist->threads, group, inherit) < 0) {
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top.evlist->threads, group) < 0) {
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int err = errno;
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if (err == EPERM || err == EACCES) {
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@ -12,6 +12,7 @@
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#include "evlist.h"
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#include "evsel.h"
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#include "util.h"
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#include "debug.h"
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#include <sys/mman.h>
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@ -250,15 +251,19 @@ int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
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return evlist->mmap != NULL ? 0 : -ENOMEM;
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}
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static int __perf_evlist__mmap(struct perf_evlist *evlist, int cpu, int prot,
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int mask, int fd)
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static int __perf_evlist__mmap(struct perf_evlist *evlist, struct perf_evsel *evsel,
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int cpu, int prot, int mask, int fd)
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{
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evlist->mmap[cpu].prev = 0;
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evlist->mmap[cpu].mask = mask;
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evlist->mmap[cpu].base = mmap(NULL, evlist->mmap_len, prot,
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MAP_SHARED, fd, 0);
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if (evlist->mmap[cpu].base == MAP_FAILED)
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if (evlist->mmap[cpu].base == MAP_FAILED) {
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if (evlist->cpus->map[cpu] == -1 && evsel->attr.inherit)
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ui__warning("Inherit is not allowed on per-task "
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"events using mmap.\n");
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return -1;
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}
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perf_evlist__add_pollfd(evlist, fd);
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return 0;
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@ -312,7 +317,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite)
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if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT,
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FD(first_evsel, cpu, 0)) != 0)
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goto out_unmap;
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} else if (__perf_evlist__mmap(evlist, cpu, prot, mask, fd) < 0)
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} else if (__perf_evlist__mmap(evlist, evsel, cpu,
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prot, mask, fd) < 0)
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goto out_unmap;
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if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
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@ -175,7 +175,7 @@ int __perf_evsel__read(struct perf_evsel *evsel,
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}
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static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
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struct thread_map *threads, bool group, bool inherit)
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struct thread_map *threads, bool group)
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{
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int cpu, thread;
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unsigned long flags = 0;
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@ -192,19 +192,6 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
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for (cpu = 0; cpu < cpus->nr; cpu++) {
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int group_fd = -1;
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/*
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* Don't allow mmap() of inherited per-task counters. This
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* would create a performance issue due to all children writing
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* to the same buffer.
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*
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* FIXME:
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* Proper fix is not to pass 'inherit' to perf_evsel__open*,
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* but a 'flags' parameter, with 'group' folded there as well,
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* then introduce a PERF_O_{MMAP,GROUP,INHERIT} enum, and if
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* O_MMAP is set, emit a warning if cpu < 0 and O_INHERIT is
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* set. Lets go for the minimal fix first tho.
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*/
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evsel->attr.inherit = (cpus->map[cpu] >= 0) && inherit;
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for (thread = 0; thread < threads->nr; thread++) {
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@ -253,7 +240,7 @@ static struct {
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};
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int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
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struct thread_map *threads, bool group, bool inherit)
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struct thread_map *threads, bool group)
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{
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if (cpus == NULL) {
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/* Work around old compiler warnings about strict aliasing */
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@ -263,19 +250,19 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
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if (threads == NULL)
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threads = &empty_thread_map.map;
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return __perf_evsel__open(evsel, cpus, threads, group, inherit);
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return __perf_evsel__open(evsel, cpus, threads, group);
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}
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int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
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struct cpu_map *cpus, bool group, bool inherit)
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struct cpu_map *cpus, bool group)
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{
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return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group, inherit);
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return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group);
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}
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int perf_evsel__open_per_thread(struct perf_evsel *evsel,
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struct thread_map *threads, bool group, bool inherit)
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struct thread_map *threads, bool group)
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{
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return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group, inherit);
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return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group);
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}
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static int perf_event__parse_id_sample(const union perf_event *event, u64 type,
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@ -81,11 +81,11 @@ void perf_evsel__free_id(struct perf_evsel *evsel);
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void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
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int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
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struct cpu_map *cpus, bool group, bool inherit);
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struct cpu_map *cpus, bool group);
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int perf_evsel__open_per_thread(struct perf_evsel *evsel,
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struct thread_map *threads, bool group, bool inherit);
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struct thread_map *threads, bool group);
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int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
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struct thread_map *threads, bool group, bool inherit);
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struct thread_map *threads, bool group);
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#define perf_evsel__match(evsel, t, c) \
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(evsel->attr.type == PERF_TYPE_##t && \
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@ -498,11 +498,11 @@ static PyObject *pyrf_evsel__open(struct pyrf_evsel *pevsel,
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struct cpu_map *cpus = NULL;
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struct thread_map *threads = NULL;
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PyObject *pcpus = NULL, *pthreads = NULL;
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int group = 0, overwrite = 0;
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static char *kwlist[] = {"cpus", "threads", "group", "overwrite", NULL, NULL};
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int group = 0, inherit = 0;
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static char *kwlist[] = {"cpus", "threads", "group", "inherit", NULL, NULL};
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if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|OOii", kwlist,
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&pcpus, &pthreads, &group, &overwrite))
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&pcpus, &pthreads, &group, &inherit))
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return NULL;
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if (pthreads != NULL)
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@ -511,7 +511,8 @@ static PyObject *pyrf_evsel__open(struct pyrf_evsel *pevsel,
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if (pcpus != NULL)
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cpus = ((struct pyrf_cpu_map *)pcpus)->cpus;
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if (perf_evsel__open(evsel, cpus, threads, group, overwrite) < 0) {
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evsel->attr.inherit = inherit;
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if (perf_evsel__open(evsel, cpus, threads, group) < 0) {
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PyErr_SetFromErrno(PyExc_OSError);
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return NULL;
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}
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