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perf evsel: Fix use of inherit

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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>
This commit is contained in:
Arnaldo Carvalho de Melo 2011-04-14 11:20:14 -03:00
parent db9a9cbc81
commit 5d2cd90922
8 changed files with 42 additions and 43 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
tools/perf/builtin-record.c
View file

@ -163,6 +163,7 @@ static void config_attr(struct perf_evsel *evsel, struct perf_evlist *evlist)
struct perf_event_attr *attr = &evsel->attr;
int track = !evsel->idx; /* only the first counter needs these */
attr->inherit = !no_inherit;
attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
PERF_FORMAT_TOTAL_TIME_RUNNING |
PERF_FORMAT_ID;
@ -251,6 +252,9 @@ static void open_counters(struct perf_evlist *evlist)
{
struct perf_evsel *pos;
if (evlist->cpus->map[0] < 0)
no_inherit = true;
list_for_each_entry(pos, &evlist->entries, node) {
struct perf_event_attr *attr = &pos->attr;
/*
@ -271,8 +275,7 @@ static void open_counters(struct perf_evlist *evlist)
retry_sample_id:
attr->sample_id_all = sample_id_all_avail ? 1 : 0;
try_again:
if (perf_evsel__open(pos, evlist->cpus, evlist->threads, group,
!no_inherit) < 0) {
if (perf_evsel__open(pos, evlist->cpus, evlist->threads, group) < 0) {
int err = errno;
if (err == EPERM || err == EACCES) {

9
tools/perf/builtin-stat.c
View file

@ -167,16 +167,17 @@ static int create_perf_stat_counter(struct perf_evsel *evsel)
attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
PERF_FORMAT_TOTAL_TIME_RUNNING;
if (system_wide)
return perf_evsel__open_per_cpu(evsel, evsel_list->cpus, false, false);
attr->inherit = !no_inherit;
if (system_wide)
return perf_evsel__open_per_cpu(evsel, evsel_list->cpus, false);
if (target_pid == -1 && target_tid == -1) {
attr->disabled = 1;
attr->enable_on_exec = 1;
}
return perf_evsel__open_per_thread(evsel, evsel_list->threads, false, false);
return perf_evsel__open_per_thread(evsel, evsel_list->threads, false);
}
/*

10
tools/perf/builtin-test.c
View file

@ -290,7 +290,7 @@ static int test__open_syscall_event(void)
goto out_thread_map_delete;
}
if (perf_evsel__open_per_thread(evsel, threads, false, false) < 0) {
if (perf_evsel__open_per_thread(evsel, threads, false) < 0) {
pr_debug("failed to open counter: %s, "
"tweak /proc/sys/kernel/perf_event_paranoid?\n",
strerror(errno));
@ -303,7 +303,7 @@ static int test__open_syscall_event(void)
}
if (perf_evsel__read_on_cpu(evsel, 0, 0) < 0) {
pr_debug("perf_evsel__open_read_on_cpu\n");
pr_debug("perf_evsel__read_on_cpu\n");
goto out_close_fd;
}
@ -365,7 +365,7 @@ static int test__open_syscall_event_on_all_cpus(void)
goto out_thread_map_delete;
}
if (perf_evsel__open(evsel, cpus, threads, false, false) < 0) {
if (perf_evsel__open(evsel, cpus, threads, false) < 0) {
pr_debug("failed to open counter: %s, "
"tweak /proc/sys/kernel/perf_event_paranoid?\n",
strerror(errno));
@ -418,7 +418,7 @@ static int test__open_syscall_event_on_all_cpus(void)
continue;
if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
pr_debug("perf_evsel__open_read_on_cpu\n");
pr_debug("perf_evsel__read_on_cpu\n");
err = -1;
break;
}
@ -529,7 +529,7 @@ static int test__basic_mmap(void)
perf_evlist__add(evlist, evsels[i]);
if (perf_evsel__open(evsels[i], cpus, threads, false, false) < 0) {
if (perf_evsel__open(evsels[i], cpus, threads, false) < 0) {
pr_debug("failed to open counter: %s, "
"tweak /proc/sys/kernel/perf_event_paranoid?\n",
strerror(errno));

3
tools/perf/builtin-top.c
View file

@ -845,9 +845,10 @@ static void start_counters(struct perf_evlist *evlist)
}
attr->mmap = 1;
attr->inherit = inherit;
try_again:
if (perf_evsel__open(counter, top.evlist->cpus,
top.evlist->threads, group, inherit) < 0) {
top.evlist->threads, group) < 0) {
int err = errno;
if (err == EPERM || err == EACCES) {

14
tools/perf/util/evlist.c
View file

@ -12,6 +12,7 @@
#include "evlist.h"
#include "evsel.h"
#include "util.h"
#include "debug.h"
#include <sys/mman.h>
@ -250,15 +251,19 @@ int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
return evlist->mmap != NULL ? 0 : -ENOMEM;
}
static int __perf_evlist__mmap(struct perf_evlist *evlist, int cpu, int prot,
int mask, int fd)
static int __perf_evlist__mmap(struct perf_evlist *evlist, struct perf_evsel *evsel,
int cpu, int prot, int mask, int fd)
{
evlist->mmap[cpu].prev = 0;
evlist->mmap[cpu].mask = mask;
evlist->mmap[cpu].base = mmap(NULL, evlist->mmap_len, prot,
MAP_SHARED, fd, 0);
if (evlist->mmap[cpu].base == MAP_FAILED)
if (evlist->mmap[cpu].base == MAP_FAILED) {
if (evlist->cpus->map[cpu] == -1 && evsel->attr.inherit)
ui__warning("Inherit is not allowed on per-task "
"events using mmap.\n");
return -1;
}
perf_evlist__add_pollfd(evlist, fd);
return 0;
@ -312,7 +317,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite)
if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT,
FD(first_evsel, cpu, 0)) != 0)
goto out_unmap;
} else if (__perf_evlist__mmap(evlist, cpu, prot, mask, fd) < 0)
} else if (__perf_evlist__mmap(evlist, evsel, cpu,
prot, mask, fd) < 0)
goto out_unmap;
if ((evsel->attr.read_format & PERF_FORMAT_ID) &&

27
tools/perf/util/evsel.c
View file

@ -175,7 +175,7 @@ int __perf_evsel__read(struct perf_evsel *evsel,
}
static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
struct thread_map *threads, bool group, bool inherit)
struct thread_map *threads, bool group)
{
int cpu, thread;
unsigned long flags = 0;
@ -192,19 +192,6 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
for (cpu = 0; cpu < cpus->nr; cpu++) {
int group_fd = -1;
/*
* Don't allow mmap() of inherited per-task counters. This
* would create a performance issue due to all children writing
* to the same buffer.
*
* FIXME:
* Proper fix is not to pass 'inherit' to perf_evsel__open*,
* but a 'flags' parameter, with 'group' folded there as well,
* then introduce a PERF_O_{MMAP,GROUP,INHERIT} enum, and if
* O_MMAP is set, emit a warning if cpu < 0 and O_INHERIT is
* set. Lets go for the minimal fix first tho.
*/
evsel->attr.inherit = (cpus->map[cpu] >= 0) && inherit;
for (thread = 0; thread < threads->nr; thread++) {
@ -253,7 +240,7 @@ static struct {
};
int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
struct thread_map *threads, bool group, bool inherit)
struct thread_map *threads, bool group)
{
if (cpus == NULL) {
/* Work around old compiler warnings about strict aliasing */
@ -263,19 +250,19 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
if (threads == NULL)
threads = &empty_thread_map.map;
return __perf_evsel__open(evsel, cpus, threads, group, inherit);
return __perf_evsel__open(evsel, cpus, threads, group);
}
int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
struct cpu_map *cpus, bool group, bool inherit)
struct cpu_map *cpus, bool group)
{
return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group, inherit);
return __perf_evsel__open(evsel, cpus, &empty_thread_map.map, group);
}
int perf_evsel__open_per_thread(struct perf_evsel *evsel,
struct thread_map *threads, bool group, bool inherit)
struct thread_map *threads, bool group)
{
return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group, inherit);
return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group);
}
static int perf_event__parse_id_sample(const union perf_event *event, u64 type,

6
tools/perf/util/evsel.h
View file

@ -81,11 +81,11 @@ void perf_evsel__free_id(struct perf_evsel *evsel);
void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
struct cpu_map *cpus, bool group, bool inherit);
struct cpu_map *cpus, bool group);
int perf_evsel__open_per_thread(struct perf_evsel *evsel,
struct thread_map *threads, bool group, bool inherit);
struct thread_map *threads, bool group);
int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
struct thread_map *threads, bool group, bool inherit);
struct thread_map *threads, bool group);
#define perf_evsel__match(evsel, t, c) \
(evsel->attr.type == PERF_TYPE_##t && \

9
tools/perf/util/python.c
View file

@ -498,11 +498,11 @@ static PyObject *pyrf_evsel__open(struct pyrf_evsel *pevsel,
struct cpu_map *cpus = NULL;
struct thread_map *threads = NULL;
PyObject *pcpus = NULL, *pthreads = NULL;
int group = 0, overwrite = 0;
static char *kwlist[] = {"cpus", "threads", "group", "overwrite", NULL, NULL};
int group = 0, inherit = 0;
static char *kwlist[] = {"cpus", "threads", "group", "inherit", NULL, NULL};
if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|OOii", kwlist,
&pcpus, &pthreads, &group, &overwrite))
&pcpus, &pthreads, &group, &inherit))
return NULL;
if (pthreads != NULL)
@ -511,7 +511,8 @@ static PyObject *pyrf_evsel__open(struct pyrf_evsel *pevsel,
if (pcpus != NULL)
cpus = ((struct pyrf_cpu_map *)pcpus)->cpus;
if (perf_evsel__open(evsel, cpus, threads, group, overwrite) < 0) {
evsel->attr.inherit = inherit;
if (perf_evsel__open(evsel, cpus, threads, group) < 0) {
PyErr_SetFromErrno(PyExc_OSError);
return NULL;
}