perf tools: Support pipeline stage cycles for powerpc

The pipeline stage cycles details can be recorded on powerpc from the
contents of Performance Monitor Unit (PMU) registers. On ISA v3.1
platform, sampling registers exposes the cycles spent in different
pipeline stages. Patch adds perf tools support to present two of the
cycle counter information along with memory latency (weight).

Re-use the field 'ins_lat' for storing the first pipeline stage cycle.
This is stored in 'var2_w' field of 'perf_sample_weight'.

Add a new field 'p_stage_cyc' to store the second pipeline stage cycle
which is stored in 'var3_w' field of perf_sample_weight.

Add new sort function 'Pipeline Stage Cycle' and include this in
default_mem_sort_order[]. This new sort function may be used to denote
some other pipeline stage in another architecture. So add this to list
of sort entries that can have dynamic header string.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: https://lore.kernel.org/r/1616425047-1666-5-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-report.txt

@@ -112,6 +112,8 @@ OPTIONS
 	- ins_lat: Instruction latency in core cycles. This is the global instruction
 	  latency
 	- local_ins_lat: Local instruction latency version
+	- p_stage_cyc: On powerpc, this presents the number of cycles spent in a
+	  pipeline stage. And currently supported only on powerpc.
 
 	By default, comm, dso and symbol keys are used.
 	(i.e. --sort comm,dso,symbol)

tools/perf/arch/powerpc/util/event.c

@@ -18,8 +18,11 @@ void arch_perf_parse_sample_weight(struct perf_sample *data,
 	weight.full = *array;
 	if (type & PERF_SAMPLE_WEIGHT)
 		data->weight = weight.full;
-	else
+	else {
 		data->weight = weight.var1_dw;
+		data->ins_lat = weight.var2_w;
+		data->p_stage_cyc = weight.var3_w;
+	}
 }
 
 void arch_perf_synthesize_sample_weight(const struct perf_sample *data,
@@ -27,6 +30,17 @@ void arch_perf_synthesize_sample_weight(const struct perf_sample *data,
 {
 	*array = data->weight;
 
-	if (type & PERF_SAMPLE_WEIGHT_STRUCT)
+	if (type & PERF_SAMPLE_WEIGHT_STRUCT) {
 		*array &= 0xffffffff;
+		*array |= ((u64)data->ins_lat << 32);
+	}
+}
+
+const char *arch_perf_header_entry(const char *se_header)
+{
+	if (!strcmp(se_header, "Local INSTR Latency"))
+		return "Finish Cyc";
+	else if (!strcmp(se_header, "Pipeline Stage Cycle"))
+		return "Dispatch Cyc";
+	return se_header;
 }

tools/perf/util/event.h

@@ -147,6 +147,7 @@ struct perf_sample {
 	u8  cpumode;
 	u16 misc;
 	u16 ins_lat;
+	u16 p_stage_cyc;
 	bool no_hw_idx;		/* No hw_idx collected in branch_stack */
 	char insn[MAX_INSN];
 	void *raw_data;

tools/perf/util/hist.c

@@ -211,6 +211,7 @@ void hists__calc_col_len(struct hists *hists, struct hist_entry *h)
 	hists__new_col_len(hists, HISTC_MEM_BLOCKED, 10);
 	hists__new_col_len(hists, HISTC_LOCAL_INS_LAT, 13);
 	hists__new_col_len(hists, HISTC_GLOBAL_INS_LAT, 13);
+	hists__new_col_len(hists, HISTC_P_STAGE_CYC, 13);
 	if (symbol_conf.nanosecs)
 		hists__new_col_len(hists, HISTC_TIME, 16);
 	else
@@ -289,13 +290,14 @@ static long hist_time(unsigned long htime)
 }
 
 static void he_stat__add_period(struct he_stat *he_stat, u64 period,
-				u64 weight, u64 ins_lat)
+				u64 weight, u64 ins_lat, u64 p_stage_cyc)
 {
 
 	he_stat->period		+= period;
 	he_stat->weight		+= weight;
 	he_stat->nr_events	+= 1;
 	he_stat->ins_lat	+= ins_lat;
+	he_stat->p_stage_cyc	+= p_stage_cyc;
 }
 
 static void he_stat__add_stat(struct he_stat *dest, struct he_stat *src)
@@ -308,6 +310,7 @@ static void he_stat__add_stat(struct he_stat *dest, struct he_stat *src)
 	dest->nr_events		+= src->nr_events;
 	dest->weight		+= src->weight;
 	dest->ins_lat		+= src->ins_lat;
+	dest->p_stage_cyc		+= src->p_stage_cyc;
 }
 
 static void he_stat__decay(struct he_stat *he_stat)
@@ -597,6 +600,7 @@ static struct hist_entry *hists__findnew_entry(struct hists *hists,
 	u64 period = entry->stat.period;
 	u64 weight = entry->stat.weight;
 	u64 ins_lat = entry->stat.ins_lat;
+	u64 p_stage_cyc = entry->stat.p_stage_cyc;
 	bool leftmost = true;
 
 	p = &hists->entries_in->rb_root.rb_node;
@@ -615,11 +619,11 @@ static struct hist_entry *hists__findnew_entry(struct hists *hists,
 
 		if (!cmp) {
 			if (sample_self) {
-				he_stat__add_period(&he->stat, period, weight, ins_lat);
+				he_stat__add_period(&he->stat, period, weight, ins_lat, p_stage_cyc);
 				hist_entry__add_callchain_period(he, period);
 			}
 			if (symbol_conf.cumulate_callchain)
-				he_stat__add_period(he->stat_acc, period, weight, ins_lat);
+				he_stat__add_period(he->stat_acc, period, weight, ins_lat, p_stage_cyc);
 
 			/*
 			 * This mem info was allocated from sample__resolve_mem
@@ -731,6 +735,7 @@ __hists__add_entry(struct hists *hists,
 			.period	= sample->period,
 			.weight = sample->weight,
 			.ins_lat = sample->ins_lat,
+			.p_stage_cyc = sample->p_stage_cyc,
 		},
 		.parent = sym_parent,
 		.filtered = symbol__parent_filter(sym_parent) | al->filtered,

tools/perf/util/hist.h

@@ -75,6 +75,7 @@ enum hist_column {
 	HISTC_MEM_BLOCKED,
 	HISTC_LOCAL_INS_LAT,
 	HISTC_GLOBAL_INS_LAT,
+	HISTC_P_STAGE_CYC,
 	HISTC_NR_COLS, /* Last entry */
 };
 

tools/perf/util/session.c

@@ -1302,8 +1302,10 @@ static void dump_sample(struct evsel *evsel, union perf_event *event,
 
 	if (sample_type & PERF_SAMPLE_WEIGHT_TYPE) {
 		printf("... weight: %" PRIu64 "", sample->weight);
-			if (sample_type & PERF_SAMPLE_WEIGHT_STRUCT)
+			if (sample_type & PERF_SAMPLE_WEIGHT_STRUCT) {
 				printf(",0x%"PRIx16"", sample->ins_lat);
+				printf(",0x%"PRIx16"", sample->p_stage_cyc);
+			}
 		printf("\n");
 	}
 

tools/perf/util/sort.c

@@ -37,7 +37,7 @@ const char	default_parent_pattern[] = "^sys_|^do_page_fault";
 const char	*parent_pattern = default_parent_pattern;
 const char	*default_sort_order = "comm,dso,symbol";
 const char	default_branch_sort_order[] = "comm,dso_from,symbol_from,symbol_to,cycles";
-const char	default_mem_sort_order[] = "local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked,blocked,local_ins_lat";
+const char	default_mem_sort_order[] = "local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked,blocked,local_ins_lat,p_stage_cyc";
 const char	default_top_sort_order[] = "dso,symbol";
 const char	default_diff_sort_order[] = "dso,symbol";
 const char	default_tracepoint_sort_order[] = "trace";
@@ -46,7 +46,7 @@ const char	*field_order;
 regex_t		ignore_callees_regex;
 int		have_ignore_callees = 0;
 enum sort_mode	sort__mode = SORT_MODE__NORMAL;
-const char	*dynamic_headers[] = {"local_ins_lat"};
+const char	*dynamic_headers[] = {"local_ins_lat", "p_stage_cyc"};
 
 /*
  * Replaces all occurrences of a char used with the:
@@ -1410,6 +1410,25 @@ struct sort_entry sort_global_ins_lat = {
 	.se_width_idx	= HISTC_GLOBAL_INS_LAT,
 };
 
+static int64_t
+sort__global_p_stage_cyc_cmp(struct hist_entry *left, struct hist_entry *right)
+{
+	return left->stat.p_stage_cyc - right->stat.p_stage_cyc;
+}
+
+static int hist_entry__p_stage_cyc_snprintf(struct hist_entry *he, char *bf,
+					size_t size, unsigned int width)
+{
+	return repsep_snprintf(bf, size, "%-*u", width, he->stat.p_stage_cyc);
+}
+
+struct sort_entry sort_p_stage_cyc = {
+	.se_header      = "Pipeline Stage Cycle",
+	.se_cmp         = sort__global_p_stage_cyc_cmp,
+	.se_snprintf	= hist_entry__p_stage_cyc_snprintf,
+	.se_width_idx	= HISTC_P_STAGE_CYC,
+};
+
 struct sort_entry sort_mem_daddr_sym = {
 	.se_header	= "Data Symbol",
 	.se_cmp		= sort__daddr_cmp,
@@ -1853,6 +1872,7 @@ static struct sort_dimension common_sort_dimensions[] = {
 	DIM(SORT_CODE_PAGE_SIZE, "code_page_size", sort_code_page_size),
 	DIM(SORT_LOCAL_INS_LAT, "local_ins_lat", sort_local_ins_lat),
 	DIM(SORT_GLOBAL_INS_LAT, "ins_lat", sort_global_ins_lat),
+	DIM(SORT_PIPELINE_STAGE_CYC, "p_stage_cyc", sort_p_stage_cyc),
 };
 
 #undef DIM

tools/perf/util/sort.h

@@ -51,6 +51,7 @@ struct he_stat {
 	u64			period_guest_us;
 	u64			weight;
 	u64			ins_lat;
+	u64			p_stage_cyc;
 	u32			nr_events;
 };
 
@@ -234,6 +235,7 @@ enum sort_type {
 	SORT_CODE_PAGE_SIZE,
 	SORT_LOCAL_INS_LAT,
 	SORT_GLOBAL_INS_LAT,
+	SORT_PIPELINE_STAGE_CYC,
 
 	/* branch stack specific sort keys */
 	__SORT_BRANCH_STACK,