[tip:perf/core] perf mmap: Implement dedicated memory buffer for data compression

From: tip-bot for Alexey Budankov
Date: Sat May 18 2019 - 05:23:30 EST


Commit-ID: 51255a8af7c41c876c2d715a35ab03c13302a607
Gitweb: https://git.kernel.org/tip/51255a8af7c41c876c2d715a35ab03c13302a607
Author: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
AuthorDate: Mon, 18 Mar 2019 20:42:19 +0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 15 May 2019 16:36:49 -0300

perf mmap: Implement dedicated memory buffer for data compression

Implemented mmap data buffer that is used as the memory to operate
on when compressing data in case of serial trace streaming.

Signed-off-by: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
Reviewed-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/49b31321-0f70-392b-9a4f-649d3affe090@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 8 +++++++-
tools/perf/util/evlist.c | 8 +++++---
tools/perf/util/evlist.h | 2 +-
tools/perf/util/mmap.c | 30 ++++++++++++++++++++++++++++--
tools/perf/util/mmap.h | 4 +++-
5 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 45a80b3584ad..ca6d7488e34b 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -372,6 +372,8 @@ static int record__mmap_flush_parse(const struct option *opt,
return 0;
}

+static unsigned int comp_level_max = 22;
+
static int record__comp_enabled(struct record *rec)
{
return rec->opts.comp_level > 0;
@@ -587,7 +589,7 @@ static int record__mmap_evlist(struct record *rec,
opts->auxtrace_mmap_pages,
opts->auxtrace_snapshot_mode,
opts->nr_cblocks, opts->affinity,
- opts->mmap_flush) < 0) {
+ opts->mmap_flush, opts->comp_level) < 0) {
if (errno == EPERM) {
pr_err("Permission error mapping pages.\n"
"Consider increasing "
@@ -2298,6 +2300,10 @@ int cmd_record(int argc, const char **argv)
pr_debug("affinity: %s\n", affinity_tags[rec->opts.affinity]);
pr_debug("mmap flush: %d\n", rec->opts.mmap_flush);

+ if (rec->opts.comp_level > comp_level_max)
+ rec->opts.comp_level = comp_level_max;
+ pr_debug("comp level: %d\n", rec->opts.comp_level);
+
err = __cmd_record(&record, argc, argv);
out:
perf_evlist__delete(rec->evlist);
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 4b6783ff5813..69d0fa8ab16f 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1009,7 +1009,8 @@ 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, int nr_cblocks, int affinity, int flush)
+ bool auxtrace_overwrite, int nr_cblocks, int affinity, int flush,
+ int comp_level)
{
struct perf_evsel *evsel;
const struct cpu_map *cpus = evlist->cpus;
@@ -1019,7 +1020,8 @@ 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 = { .nr_cblocks = nr_cblocks, .affinity = affinity, .flush = flush };
+ struct mmap_params mp = { .nr_cblocks = nr_cblocks, .affinity = affinity, .flush = flush,
+ .comp_level = comp_level };

if (!evlist->mmap)
evlist->mmap = perf_evlist__alloc_mmap(evlist, false);
@@ -1051,7 +1053,7 @@ 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, 0, PERF_AFFINITY_SYS, 1);
+ return perf_evlist__mmap_ex(evlist, pages, 0, false, 0, PERF_AFFINITY_SYS, 1, 0);
}

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 c9a0f72677fd..49354fe24d5f 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -178,7 +178,7 @@ 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, int nr_cblocks,
- int affinity, int flush);
+ int affinity, int flush, int comp_level);
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 ef3d79b2c90b..d85e73fc82e2 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -157,6 +157,10 @@ void __weak auxtrace_mmap_params__set_idx(struct auxtrace_mmap_params *mp __mayb
}

#ifdef HAVE_AIO_SUPPORT
+static int perf_mmap__aio_enabled(struct perf_mmap *map)
+{
+ return map->aio.nr_cblocks > 0;
+}

#ifdef HAVE_LIBNUMA_SUPPORT
static int perf_mmap__aio_alloc(struct perf_mmap *map, int idx)
@@ -198,7 +202,7 @@ static int perf_mmap__aio_bind(struct perf_mmap *map, int idx, int cpu, int affi

return 0;
}
-#else
+#else /* !HAVE_LIBNUMA_SUPPORT */
static int perf_mmap__aio_alloc(struct perf_mmap *map, int idx)
{
map->aio.data[idx] = malloc(perf_mmap__mmap_len(map));
@@ -359,7 +363,12 @@ int perf_mmap__aio_push(struct perf_mmap *md, void *to, int idx,

return rc;
}
-#else
+#else /* !HAVE_AIO_SUPPORT */
+static int perf_mmap__aio_enabled(struct perf_mmap *map __maybe_unused)
+{
+ return 0;
+}
+
static int perf_mmap__aio_mmap(struct perf_mmap *map __maybe_unused,
struct mmap_params *mp __maybe_unused)
{
@@ -374,6 +383,10 @@ static void perf_mmap__aio_munmap(struct perf_mmap *map __maybe_unused)
void perf_mmap__munmap(struct perf_mmap *map)
{
perf_mmap__aio_munmap(map);
+ if (map->data != NULL) {
+ munmap(map->data, perf_mmap__mmap_len(map));
+ map->data = NULL;
+ }
if (map->base != NULL) {
munmap(map->base, perf_mmap__mmap_len(map));
map->base = NULL;
@@ -442,6 +455,19 @@ int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd, int c

map->flush = mp->flush;

+ map->comp_level = mp->comp_level;
+
+ if (map->comp_level && !perf_mmap__aio_enabled(map)) {
+ map->data = mmap(NULL, perf_mmap__mmap_len(map), PROT_READ|PROT_WRITE,
+ MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
+ if (map->data == MAP_FAILED) {
+ pr_debug2("failed to mmap data buffer, error %d\n",
+ errno);
+ map->data = NULL;
+ return -1;
+ }
+ }
+
if (auxtrace_mmap__mmap(&map->auxtrace_mmap,
&mp->auxtrace_mp, map->base, fd))
return -1;
diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index b82f8c2d55c4..4e2f58d95c1f 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -40,6 +40,8 @@ struct perf_mmap {
#endif
cpu_set_t affinity_mask;
u64 flush;
+ void *data;
+ int comp_level;
};

/*
@@ -71,7 +73,7 @@ enum bkw_mmap_state {
};

struct mmap_params {
- int prot, mask, nr_cblocks, affinity, flush;
+ int prot, mask, nr_cblocks, affinity, flush, comp_level;
struct auxtrace_mmap_params auxtrace_mp;
};