The map->data buffers are used to preserve map->base profiling data
for writing to disk. AIO map->cblocks are used to queue corresponding
map->data buffers for asynchronous writing. map->cblocks objects are
located in the last page of every map->data buffer.
Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com>
---
Changes in v6:
- adjusted setting of priorities for cblocks;
Changes in v5:
- reshaped layout of data structures;
- implemented --aio option;
Changes in v4:
- converted mmap()/munmap() to malloc()/free() for mmap->data buffer
management
Changes in v2:
- converted zalloc() to calloc() for allocation of mmap_aio array,
- cleared typo and adjusted fallback branch code;
---
tools/perf/builtin-record.c | 12 +++++++++-
tools/perf/perf.h | 1 +
tools/perf/util/evlist.c | 7 +++---
tools/perf/util/evlist.h | 3 ++-
tools/perf/util/mmap.c | 53 +++++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/mmap.h | 6 ++++-
6 files changed, 76 insertions(+), 6 deletions(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 22ebeb92ac51..8eb093f8d4d5 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -326,7 +326,8 @@ static int record__mmap_evlist(struct record *rec,
if (perf_evlist__mmap_ex(evlist, opts->mmap_pages,
opts->auxtrace_mmap_pages,
- opts->auxtrace_snapshot_mode) < 0) {
+ opts->auxtrace_snapshot_mode,
+ opts->nr_cblocks) < 0) {
if (errno == EPERM) {
pr_err("Permission error mapping pages.\n"
"Consider increasing "
@@ -1519,6 +1520,7 @@ static struct record record = {
.default_per_cpu = true,
},
.proc_map_timeout = 500,
+ .nr_cblocks = 2
},
.tool = {
.sample = process_sample_event,
@@ -1678,6 +1680,8 @@ static struct option __record_options[] = {
"signal"),
OPT_BOOLEAN(0, "dry-run", &dry_run,
"Parse options then exit"),
+ OPT_INTEGER(0, "aio", &record.opts.nr_cblocks,
+ "asynchronous trace write operations (min: 1, max: 32,
default: 2)"),
OPT_END()
};
@@ -1870,6 +1874,12 @@ int cmd_record(int argc, const char **argv)
goto out;
}
+ if (!(1 <= rec->opts.nr_cblocks && rec->opts.nr_cblocks <= 32)) {
+ if (verbose > 0)
+ pr_warning("Asynchronous trace writes reset to
default.\n");
+ rec->opts.nr_cblocks = 2;
+ }
+
err = __cmd_record(&record, argc, argv);
out:
perf_evlist__delete(rec->evlist);
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 21bf7f5a3cf5..0a1ae2ae567a 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -82,6 +82,7 @@ struct record_opts {
bool use_clockid;
clockid_t clockid;
unsigned int proc_map_timeout;
+ int nr_cblocks;
};
struct option;
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index e7a4b31a84fb..08be79650a85 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1018,7 +1018,8 @@ int perf_evlist__parse_mmap_pages(const struct option
*opt, const char *str,
*/
int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
unsigned int auxtrace_pages,
- bool auxtrace_overwrite)
+ bool auxtrace_overwrite,
+ int nr_cblocks)
{
struct perf_evsel *evsel;
const struct cpu_map *cpus = evlist->cpus;
@@ -1028,7 +1029,7 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist,
unsigned int pages,
* Its value is decided by evsel's write_backward.
* So &mp should not be passed through const pointer.
*/
- struct mmap_params mp;
+ struct mmap_params mp = { .nr_cblocks = nr_cblocks };
if (!evlist->mmap)
evlist->mmap = perf_evlist__alloc_mmap(evlist, false);
@@ -1060,7 +1061,7 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist,
unsigned int pages,
int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages)
{
- return perf_evlist__mmap_ex(evlist, pages, 0, false);
+ return perf_evlist__mmap_ex(evlist, pages, 0, false, 2);
}
int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index dc66436add98..a94d3c613254 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -162,7 +162,8 @@ unsigned long perf_event_mlock_kb_in_pages(void);
int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
unsigned int auxtrace_pages,
- bool auxtrace_overwrite);
+ bool auxtrace_overwrite,
+ int nr_cblocks);
int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages);
void perf_evlist__munmap(struct perf_evlist *evlist);
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index fc832676a798..384d17cd1379 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -155,6 +155,14 @@ void __weak auxtrace_mmap_params__set_idx(struct
auxtrace_mmap_params *mp __mayb
void perf_mmap__munmap(struct perf_mmap *map)
{
+ int i;
+ if (map->data) {
+ for (i = 0; i < map->nr_cblocks; ++i)
+ zfree(&(map->data[i]));
+ zfree(&(map->data));
+ }
+ if (map->cblocks)
+ zfree(&(map->cblocks));
if (map->base != NULL) {
munmap(map->base, perf_mmap__mmap_len(map));
map->base = NULL;
@@ -166,6 +174,7 @@ void perf_mmap__munmap(struct perf_mmap *map)
int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd)
{
+ int i;
/*
* The last one will be done at perf_mmap__consume(), so that we
* make sure we don't prevent tools from consuming every last event in
@@ -190,6 +199,50 @@ int perf_mmap__mmap(struct perf_mmap *map, struct
mmap_params *mp, int fd)
map->base = NULL;
return -1;
}
+ map->nr_cblocks = mp->nr_cblocks;
+ map->cblocks = calloc(map->nr_cblocks, sizeof(struct aiocb*));
+ if (!map->cblocks) {
+ pr_debug2("failed to allocate perf event data buffers, error
%d\n",
+ errno);
+ return -1;
+ }
+ map->data = calloc(map->nr_cblocks, sizeof(void*));
+ if (map->data) {
+ int delta_max = sysconf(_SC_AIO_PRIO_DELTA_MAX);
+ for (i = 0; i < map->nr_cblocks; ++i) {
+ map->data[i] = malloc(perf_mmap__mmap_len(map));
+ if (map->data[i]) {
+ int prio;
+ unsigned char *data = map->data[i];
+ map->cblocks[i] = (struct aiocb
*)&data[map->mask + 1];
+ memset(map->cblocks[i], 0, sizeof(struct
aiocb));
+ /* Use cblock.aio_fildes value different from -1
+ * to denote started aio write operation on the
+ * cblock so it requires explicit
record__aio_sync()
+ * call prior the cblock may be reused again.
+ */
+ map->cblocks[i]->aio_fildes = -1;
+ /* Allocate cblocks with decreasing priority to
+ * have faster aio_write() calls because queued
+ * requests are kept in separate per-prio queues
+ * and adding a new request iterates thru
shorter
+ * per-prio list.
+ */
+ prio = delta_max - i;
+ if (prio < 0)
+ prio = 0;
+ map->cblocks[i]->aio_reqprio = prio;
+ } else {
+ pr_debug2("failed to allocate perf event data
buffer, error %d\n",
+ errno);
+ return -1;
+ }
+ }
+ } else {
+ pr_debug2("failed to alloc perf event data buffers, error %d\n",
+ errno);
+ return -1;
+ }
map->fd = fd;
if (auxtrace_mmap__mmap(&map->auxtrace_mmap,
diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index d82294db1295..4a9bb0ecae4f 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -6,6 +6,7 @@
#include <linux/types.h>
#include <asm/barrier.h>
#include <stdbool.h>
+#include <aio.h>
#include "auxtrace.h"
#include "event.h"
@@ -25,6 +26,9 @@ struct perf_mmap {
bool overwrite;
struct auxtrace_mmap auxtrace_mmap;
char event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
+ void **data;
+ struct aiocb **cblocks;
+ int nr_cblocks;
};
/*
@@ -56,7 +60,7 @@ enum bkw_mmap_state {
};
struct mmap_params {
- int prot, mask;
+ int prot, mask, nr_cblocks;
struct auxtrace_mmap_params auxtrace_mp;
};
