Commit 70082dd9 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf evsel: Introduce mmap support



Out of the code in 'perf top'. Record is next in line.

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>
LKML-Reference: <new-submission>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent dd7927f4
......@@ -1095,43 +1095,12 @@ static void event__process_sample(const event_t *self,
}
}
struct mmap_data {
void *base;
int mask;
unsigned int prev;
};
static int perf_evsel__alloc_mmap_per_thread(struct perf_evsel *evsel,
int ncpus, int nthreads)
{
evsel->priv = xyarray__new(ncpus, nthreads, sizeof(struct mmap_data));
return evsel->priv != NULL ? 0 : -ENOMEM;
}
static void perf_evsel__free_mmap(struct perf_evsel *evsel)
{
xyarray__delete(evsel->priv);
evsel->priv = NULL;
}
static unsigned int mmap_read_head(struct mmap_data *md)
{
struct perf_event_mmap_page *pc = md->base;
int head;
head = pc->data_head;
rmb();
return head;
}
static void perf_session__mmap_read_counter(struct perf_session *self,
struct perf_evsel *evsel,
int cpu, int thread_idx)
{
struct xyarray *mmap_array = evsel->priv;
struct mmap_data *md = xyarray__entry(mmap_array, cpu, thread_idx);
unsigned int head = mmap_read_head(md);
struct perf_mmap *md = xyarray__entry(evsel->mmap, cpu, thread_idx);
unsigned int head = perf_mmap__read_head(md);
unsigned int old = md->prev;
unsigned char *data = md->base + page_size;
struct sample_data sample;
......@@ -1210,35 +1179,9 @@ static void perf_session__mmap_read(struct perf_session *self)
}
}
static void start_counter(int i, struct perf_evlist *evlist,
struct perf_evsel *evsel)
{
struct xyarray *mmap_array = evsel->priv;
struct mmap_data *mm;
int thread_index;
for (thread_index = 0; thread_index < threads->nr; thread_index++) {
assert(FD(evsel, i, thread_index) >= 0);
fcntl(FD(evsel, i, thread_index), F_SETFL, O_NONBLOCK);
evlist->pollfd[evlist->nr_fds].fd = FD(evsel, i, thread_index);
evlist->pollfd[evlist->nr_fds].events = POLLIN;
evlist->nr_fds++;
mm = xyarray__entry(mmap_array, i, thread_index);
mm->prev = 0;
mm->mask = mmap_pages*page_size - 1;
mm->base = mmap(NULL, (mmap_pages+1)*page_size,
PROT_READ, MAP_SHARED, FD(evsel, i, thread_index), 0);
if (mm->base == MAP_FAILED)
die("failed to mmap with %d (%s)\n", errno, strerror(errno));
}
}
static void start_counters(struct perf_evlist *evlist)
{
struct perf_evsel *counter;
int i;
list_for_each_entry(counter, &evlist->entries, node) {
struct perf_event_attr *attr = &counter->attr;
......@@ -1282,11 +1225,9 @@ try_again:
die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
exit(-1);
}
}
for (i = 0; i < cpus->nr; i++) {
list_for_each_entry(counter, &evlist->entries, node)
start_counter(i, evsel_list, counter);
if (perf_evsel__mmap(counter, cpus, threads, mmap_pages, evlist) < 0)
die("failed to mmap with %d (%s)\n", errno, strerror(errno));
}
}
......@@ -1453,7 +1394,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
usage_with_options(top_usage, options);
list_for_each_entry(pos, &evsel_list->entries, node) {
if (perf_evsel__alloc_mmap_per_thread(pos, cpus->nr, threads->nr) < 0 ||
if (perf_evsel__alloc_mmap(pos, cpus->nr, threads->nr) < 0 ||
perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
goto out_free_fd;
/*
......@@ -1485,8 +1426,6 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
status = __cmd_top();
out_free_fd:
list_for_each_entry(pos, &evsel_list->entries, node)
perf_evsel__free_mmap(pos);
perf_evlist__delete(evsel_list);
return status;
......
......@@ -94,6 +94,20 @@ void get_term_dimensions(struct winsize *ws);
#include "util/types.h"
#include <stdbool.h>
struct perf_mmap {
void *base;
int mask;
unsigned int prev;
};
static inline unsigned int perf_mmap__read_head(struct perf_mmap *mm)
{
struct perf_event_mmap_page *pc = mm->base;
int head = pc->data_head;
rmb();
return head;
}
/*
* prctl(PR_TASK_PERF_EVENTS_DISABLE) will (cheaply) disable all
* counters in the current task.
......
......@@ -60,3 +60,11 @@ int perf_evlist__alloc_pollfd(struct perf_evlist *evlist, int ncpus, int nthread
evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
return evlist->pollfd != NULL ? 0 : -ENOMEM;
}
void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
{
fcntl(fd, F_SETFL, O_NONBLOCK);
evlist->pollfd[evlist->nr_fds].fd = fd;
evlist->pollfd[evlist->nr_fds].events = POLLIN;
evlist->nr_fds++;
}
......@@ -21,5 +21,6 @@ void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry);
int perf_evlist__add_default(struct perf_evlist *evlist);
int perf_evlist__alloc_pollfd(struct perf_evlist *evlist, int ncpus, int nthreads);
void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd);
#endif /* __PERF_EVLIST_H */
#include "evsel.h"
#include "evlist.h"
#include "../perf.h"
#include "util.h"
#include "cpumap.h"
#include "thread.h"
#include <unistd.h>
#include <sys/mman.h>
#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx)
......@@ -49,10 +53,32 @@ void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
}
}
void perf_evsel__munmap(struct perf_evsel *evsel, int ncpus, int nthreads)
{
struct perf_mmap *mm;
int cpu, thread;
for (cpu = 0; cpu < ncpus; cpu++)
for (thread = 0; thread < nthreads; ++thread) {
mm = xyarray__entry(evsel->mmap, cpu, thread);
if (mm->base != NULL) {
munmap(mm->base, evsel->mmap_len);
mm->base = NULL;
}
}
}
int perf_evsel__alloc_mmap(struct perf_evsel *evsel, int ncpus, int nthreads)
{
evsel->mmap = xyarray__new(ncpus, nthreads, sizeof(struct perf_mmap));
return evsel->mmap != NULL ? 0 : -ENOMEM;
}
void perf_evsel__delete(struct perf_evsel *evsel)
{
assert(list_empty(&evsel->node));
xyarray__delete(evsel->fd);
xyarray__delete(evsel->mmap);
free(evsel);
}
......@@ -208,3 +234,48 @@ int perf_evsel__open_per_thread(struct perf_evsel *evsel,
{
return __perf_evsel__open(evsel, &empty_cpu_map.map, threads, group, inherit);
}
int perf_evsel__mmap(struct perf_evsel *evsel, struct cpu_map *cpus,
struct thread_map *threads, int pages,
struct perf_evlist *evlist)
{
unsigned int page_size = sysconf(_SC_PAGE_SIZE);
int mask = pages * page_size - 1, cpu;
struct perf_mmap *mm;
int thread;
if (evsel->mmap == NULL &&
perf_evsel__alloc_mmap(evsel, cpus->nr, threads->nr) < 0)
return -ENOMEM;
evsel->mmap_len = (pages + 1) * page_size;
for (cpu = 0; cpu < cpus->nr; cpu++) {
for (thread = 0; thread < threads->nr; thread++) {
mm = xyarray__entry(evsel->mmap, cpu, thread);
mm->prev = 0;
mm->mask = mask;
mm->base = mmap(NULL, evsel->mmap_len, PROT_READ,
MAP_SHARED, FD(evsel, cpu, thread), 0);
if (mm->base == MAP_FAILED)
goto out_unmap;
if (evlist != NULL)
perf_evlist__add_pollfd(evlist, FD(evsel, cpu, thread));
}
}
return 0;
out_unmap:
do {
while (--thread >= 0) {
mm = xyarray__entry(evsel->mmap, cpu, thread);
munmap(mm->base, evsel->mmap_len);
mm->base = NULL;
}
thread = threads->nr;
} while (--cpu >= 0);
return -1;
}
......@@ -29,19 +29,23 @@ struct perf_evsel {
struct perf_event_attr attr;
char *filter;
struct xyarray *fd;
struct xyarray *mmap;
struct perf_counts *counts;
size_t mmap_len;
int idx;
void *priv;
};
struct cpu_map;
struct thread_map;
struct perf_evlist;
struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx);
void perf_evsel__delete(struct perf_evsel *evsel);
int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus);
int perf_evsel__alloc_mmap(struct perf_evsel *evsel, int ncpus, int nthreads);
void perf_evsel__free_fd(struct perf_evsel *evsel);
void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
......@@ -51,6 +55,10 @@ int perf_evsel__open_per_thread(struct perf_evsel *evsel,
struct thread_map *threads, bool group, bool inherit);
int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
struct thread_map *threads, bool group, bool inherit);
int perf_evsel__mmap(struct perf_evsel *evsel, struct cpu_map *cpus,
struct thread_map *threads, int pages,
struct perf_evlist *evlist);
void perf_evsel__munmap(struct perf_evsel *evsel, int ncpus, int nthreads);
#define perf_evsel__match(evsel, t, c) \
(evsel->attr.type == PERF_TYPE_##t && \
......
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