[PATCH v9 04/12] perf record: implement COMPRESSED event record and its attributes

[Alexey Budankov <alexey.budankov@linux.intel.com>]

Implemented PERF_RECORD_COMPRESSED event, related data types, header
feature and functions to write, read and print feature attributes
from the trace header section.

comp_mmap_len preserves the size of mmaped kernel buffer that was used
during collection. comp_mmap_len size is used on loading stage as the
size of decomp buffer for decompression of COMPRESSED events content.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 .../Documentation/perf.data-file-format.txt   | 24 ++++++++
 tools/perf/builtin-record.c                   |  8 +++
 tools/perf/perf.h                             |  1 +
 tools/perf/util/env.h                         | 10 ++++
 tools/perf/util/event.c                       |  1 +
 tools/perf/util/event.h                       |  7 +++
 tools/perf/util/header.c                      | 55 ++++++++++++++++++-
 tools/perf/util/header.h                      |  1 +
 8 files changed, 106 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf.data-file-format.txt b/tools/perf/Documentation/perf.data-file-format.txt
index 593ef49b273c..418fa0bce52e 100644
--- a/tools/perf/Documentation/perf.data-file-format.txt
+++ b/tools/perf/Documentation/perf.data-file-format.txt
@@ -272,6 +272,19 @@ struct {
 
 Two uint64_t for the time of first sample and the time of last sample.
 
+        HEADER_COMPRESSED = 24,
+
+struct {
+	u32	version;
+	u32	type;
+	u32	level;
+	u32	ratio;
+	u32	mmap_len;
+};
+
+Indicates that trace contains records of PERF_RECORD_COMPRESSED type
+that have perf_events records in compressed form.
+
 	other bits are reserved and should ignored for now
 	HEADER_FEAT_BITS	= 256,
 
@@ -437,6 +450,17 @@ struct auxtrace_error_event {
 Describes a header feature. These are records used in pipe-mode that
 contain information that otherwise would be in perf.data file's header.
 
+	PERF_RECORD_COMPRESSED 			= 81,
+
+struct compressed_event {
+	struct perf_event_header	header;
+	char				data[];
+};
+
+The header is followed by compressed data frame that can be decompressed
+into array of perf trace records. The size of the entire compressed event
+record including the header is limited by the max value of header.size.
+
 Event types
 
 Define the event attributes with their IDs.
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 51b7f23a0c7a..7125b780c4f4 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -369,6 +369,11 @@ static int record__mmap_flush_parse(const struct option *opt,
 	return 0;
 }
 
+static int record__comp_enabled(struct record *rec)
+{
+	return rec->opts.comp_level > 0;
+}
+
 static int process_synthesized_event(struct perf_tool *tool,
 				     union perf_event *event,
 				     struct perf_sample *sample __maybe_unused,
@@ -885,6 +890,8 @@ static void record__init_features(struct record *rec)
 		perf_header__clear_feat(&session->header, HEADER_CLOCKID);
 
 	perf_header__clear_feat(&session->header, HEADER_DIR_FORMAT);
+	if (!record__comp_enabled(rec))
+		perf_header__clear_feat(&session->header, HEADER_COMPRESSED);
 
 	perf_header__clear_feat(&session->header, HEADER_STAT);
 }
@@ -1225,6 +1232,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 		err = -1;
 		goto out_child;
 	}
+	session->header.env.comp_mmap_len = session->evlist->mmap_len;
 
 	err = bpf__apply_obj_config();
 	if (err) {
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 7886cc9771cf..2c6caad45b10 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -86,6 +86,7 @@ struct record_opts {
 	int	     nr_cblocks;
 	int	     affinity;
 	int	     mmap_flush;
+	unsigned int comp_level;
 };
 
 enum perf_affinity {
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index fb39e9af128f..7990d63ab764 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -65,6 +65,16 @@ struct perf_env {
 	unsigned long long	 memory_bsize;
 	u64                     clockid_res_ns;
 	u32                     comp_ratio;
+	u32			comp_ver;
+	u32			comp_type;
+	u32			comp_level;
+	u32			comp_mmap_len;
+};
+
+enum perf_compress_type {
+	PERF_COMP_NONE = 0,
+	PERF_COMP_ZSTD,
+	PERF_COMP_MAX
 };
 
 extern struct perf_env perf_env;
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index ba7be74fad6e..d1ad6c419724 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -68,6 +68,7 @@ static const char *perf_event__names[] = {
 	[PERF_RECORD_EVENT_UPDATE]		= "EVENT_UPDATE",
 	[PERF_RECORD_TIME_CONV]			= "TIME_CONV",
 	[PERF_RECORD_HEADER_FEATURE]		= "FEATURE",
+	[PERF_RECORD_COMPRESSED]		= "COMPRESSED",
 };
 
 static const char *perf_ns__names[] = {
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 36ae7e92dab1..8a13aefe734e 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -254,6 +254,7 @@ enum perf_user_event_type { /* above any possible kernel type */
 	PERF_RECORD_EVENT_UPDATE		= 78,
 	PERF_RECORD_TIME_CONV			= 79,
 	PERF_RECORD_HEADER_FEATURE		= 80,
+	PERF_RECORD_COMPRESSED			= 81,
 	PERF_RECORD_HEADER_MAX
 };
 
@@ -626,6 +627,11 @@ struct feature_event {
 	char				data[];
 };
 
+struct compressed_event {
+	struct perf_event_header	header;
+	char				data[];
+};
+
 union perf_event {
 	struct perf_event_header	header;
 	struct mmap_event		mmap;
@@ -659,6 +665,7 @@ union perf_event {
 	struct feature_event		feat;
 	struct ksymbol_event		ksymbol_event;
 	struct bpf_event		bpf_event;
+	struct compressed_event		pack;
 };
 
 void perf_event__print_totals(void);
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index b0683bf4d9f3..ee5dd3befa4b 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1259,6 +1259,30 @@ static int write_mem_topology(struct feat_fd *ff __maybe_unused,
 	return ret;
 }
 
+static int write_compressed(struct feat_fd *ff __maybe_unused,
+			    struct perf_evlist *evlist __maybe_unused)
+{
+	int ret;
+
+	ret = do_write(ff, &(ff->ph->env.comp_ver), sizeof(ff->ph->env.comp_ver));
+	if (ret)
+		return ret;
+
+	ret = do_write(ff, &(ff->ph->env.comp_type), sizeof(ff->ph->env.comp_type));
+	if (ret)
+		return ret;
+
+	ret = do_write(ff, &(ff->ph->env.comp_level), sizeof(ff->ph->env.comp_level));
+	if (ret)
+		return ret;
+
+	ret = do_write(ff, &(ff->ph->env.comp_ratio), sizeof(ff->ph->env.comp_ratio));
+	if (ret)
+		return ret;
+
+	return do_write(ff, &(ff->ph->env.comp_mmap_len), sizeof(ff->ph->env.comp_mmap_len));
+}
+
 static void print_hostname(struct feat_fd *ff, FILE *fp)
 {
 	fprintf(fp, "# hostname : %s\n", ff->ph->env.hostname);
@@ -1557,6 +1581,13 @@ static void print_cache(struct feat_fd *ff, FILE *fp __maybe_unused)
 	}
 }
 
+static void print_compressed(struct feat_fd *ff, FILE *fp)
+{
+	fprintf(fp, "# compressed : %s, level = %d, ratio = %d\n",
+		ff->ph->env.comp_type == PERF_COMP_ZSTD ? "Zstd" : "Unknown",
+		ff->ph->env.comp_level, ff->ph->env.comp_ratio);
+}
+
 static void print_pmu_mappings(struct feat_fd *ff, FILE *fp)
 {
 	const char *delimiter = "# pmu mappings: ";
@@ -2414,6 +2445,27 @@ static int process_dir_format(struct feat_fd *ff,
 	return do_read_u64(ff, &data->dir.version);
 }
 
+static int process_compressed(struct feat_fd *ff,
+			      void *data __maybe_unused)
+{
+	if (do_read_u32(ff, &(ff->ph->env.comp_ver)))
+		return -1;
+
+	if (do_read_u32(ff, &(ff->ph->env.comp_type)))
+		return -1;
+
+	if (do_read_u32(ff, &(ff->ph->env.comp_level)))
+		return -1;
+
+	if (do_read_u32(ff, &(ff->ph->env.comp_ratio)))
+		return -1;
+
+	if (do_read_u32(ff, &(ff->ph->env.comp_mmap_len)))
+		return -1;
+
+	return 0;
+}
+
 struct feature_ops {
 	int (*write)(struct feat_fd *ff, struct perf_evlist *evlist);
 	void (*print)(struct feat_fd *ff, FILE *fp);
@@ -2474,7 +2526,8 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
 	FEAT_OPR(SAMPLE_TIME,	sample_time,	false),
 	FEAT_OPR(MEM_TOPOLOGY,	mem_topology,	true),
 	FEAT_OPR(CLOCKID,	clockid,	false),
-	FEAT_OPN(DIR_FORMAT,	dir_format,	false)
+	FEAT_OPN(DIR_FORMAT,	dir_format,	false),
+	FEAT_OPR(COMPRESSED,	compressed,	false)
 };
 
 struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 6a231340238d..9ccfb204bd2c 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -40,6 +40,7 @@ enum {
 	HEADER_MEM_TOPOLOGY,
 	HEADER_CLOCKID,
 	HEADER_DIR_FORMAT,
+	HEADER_COMPRESSED,
 	HEADER_LAST_FEATURE,
 	HEADER_FEAT_BITS	= 256,
 };
-- 
2.20.1