[PATCH v1] perf jevents: Drop or simplify small integer values

[Ian Rogers]

Prior to this patch '0' would be dropped as the config values default
to 0. Some json values are hex and the string '0' wouldn't match '0x0'
as zero. Add a more robust is_zero test to drop these event terms.

When encoding numbers as hex, if the number is between 0 and 9
inclusive then don't add a 0x prefix.

Update test expectations for these changes.

On x86 this reduces the event/metric C string by 58,411 bytes.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/pmu-events/jevents.py | 23 ++++++++++++++++++++---
 tools/perf/tests/pmu-events.c    | 22 +++++++++++-----------
 2 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
index 53ab050c8fa4..2c7e5d61ce92 100755
--- a/tools/perf/pmu-events/jevents.py
+++ b/tools/perf/pmu-events/jevents.py
@@ -203,7 +203,7 @@ class JsonEvent:
 
     def llx(x: int) -> str:
       """Convert an int to a string similar to a printf modifier of %#llx."""
-      return '0' if x == 0 else hex(x)
+      return str(x) if x >= 0 and x < 10 else hex(x)
 
     def fixdesc(s: str) -> str:
       """Fix formatting issue for the desc string."""
@@ -294,6 +294,23 @@ class JsonEvent:
       }
       return table[unit] if unit in table else f'uncore_{unit.lower()}'
 
+    def is_zero(val: str) -> bool:
+        try:
+            if val.startswith('0x'):
+                return int(val, 16) == 0
+            else:
+                return int(val) == 0
+        except e:
+            return False
+
+    def canonicalize_value(val: str) -> str:
+        try:
+            if val.startswith('0x'):
+                return llx(int(val, 16))
+            return str(int(val))
+        except e:
+            return val
+
     eventcode = 0
     if 'EventCode' in jd:
       eventcode = int(jd['EventCode'].split(',', 1)[0], 0)
@@ -358,8 +375,8 @@ class JsonEvent:
         ('RdWrMask', 'rdwrmask='),
     ]
     for key, value in event_fields:
-      if key in jd and jd[key] != '0':
-        event += ',' + value + jd[key]
+      if key in jd and not is_zero(jd[key]):
+        event += f',{value}{canonicalize_value(jd[key])}'
     if filter:
       event += f',{filter}'
     if msr:
diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index a56d32905743..47a7c3277540 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -70,7 +70,7 @@ static const struct perf_pmu_test_event segment_reg_loads_any = {
 	.event = {
 		.pmu = "default_core",
 		.name = "segment_reg_loads.any",
-		.event = "event=0x6,period=200000,umask=0x80",
+		.event = "event=6,period=200000,umask=0x80",
 		.desc = "Number of segment register loads",
 		.topic = "other",
 	},
@@ -82,7 +82,7 @@ static const struct perf_pmu_test_event dispatch_blocked_any = {
 	.event = {
 		.pmu = "default_core",
 		.name = "dispatch_blocked.any",
-		.event = "event=0x9,period=200000,umask=0x20",
+		.event = "event=9,period=200000,umask=0x20",
 		.desc = "Memory cluster signals to block micro-op dispatch for any reason",
 		.topic = "other",
 	},
@@ -94,11 +94,11 @@ static const struct perf_pmu_test_event eist_trans = {
 	.event = {
 		.pmu = "default_core",
 		.name = "eist_trans",
-		.event = "event=0x3a,period=200000,umask=0x0",
+		.event = "event=0x3a,period=200000",
 		.desc = "Number of Enhanced Intel SpeedStep(R) Technology (EIST) transitions",
 		.topic = "other",
 	},
-	.alias_str = "event=0x3a,period=0x30d40,umask=0",
+	.alias_str = "event=0x3a,period=0x30d40",
 	.alias_long_desc = "Number of Enhanced Intel SpeedStep(R) Technology (EIST) transitions",
 };
 
@@ -128,7 +128,7 @@ static const struct perf_pmu_test_event *core_events[] = {
 static const struct perf_pmu_test_event uncore_hisi_ddrc_flux_wcmd = {
 	.event = {
 		.name = "uncore_hisi_ddrc.flux_wcmd",
-		.event = "event=0x2",
+		.event = "event=2",
 		.desc = "DDRC write commands",
 		.topic = "uncore",
 		.long_desc = "DDRC write commands",
@@ -156,13 +156,13 @@ static const struct perf_pmu_test_event unc_cbo_xsnp_response_miss_eviction = {
 static const struct perf_pmu_test_event uncore_hyphen = {
 	.event = {
 		.name = "event-hyphen",
-		.event = "event=0xe0,umask=0x00",
+		.event = "event=0xe0",
 		.desc = "UNC_CBO_HYPHEN",
 		.topic = "uncore",
 		.long_desc = "UNC_CBO_HYPHEN",
 		.pmu = "uncore_cbox",
 	},
-	.alias_str = "event=0xe0,umask=0",
+	.alias_str = "event=0xe0",
 	.alias_long_desc = "UNC_CBO_HYPHEN",
 	.matching_pmu = "uncore_cbox_0",
 };
@@ -170,13 +170,13 @@ static const struct perf_pmu_test_event uncore_hyphen = {
 static const struct perf_pmu_test_event uncore_two_hyph = {
 	.event = {
 		.name = "event-two-hyph",
-		.event = "event=0xc0,umask=0x00",
+		.event = "event=0xc0",
 		.desc = "UNC_CBO_TWO_HYPH",
 		.topic = "uncore",
 		.long_desc = "UNC_CBO_TWO_HYPH",
 		.pmu = "uncore_cbox",
 	},
-	.alias_str = "event=0xc0,umask=0",
+	.alias_str = "event=0xc0",
 	.alias_long_desc = "UNC_CBO_TWO_HYPH",
 	.matching_pmu = "uncore_cbox_0",
 };
@@ -184,7 +184,7 @@ static const struct perf_pmu_test_event uncore_two_hyph = {
 static const struct perf_pmu_test_event uncore_hisi_l3c_rd_hit_cpipe = {
 	.event = {
 		.name = "uncore_hisi_l3c.rd_hit_cpipe",
-		.event = "event=0x7",
+		.event = "event=7",
 		.desc = "Total read hits",
 		.topic = "uncore",
 		.long_desc = "Total read hits",
@@ -265,7 +265,7 @@ static const struct perf_pmu_test_event sys_ccn_pmu_read_cycles = {
 static const struct perf_pmu_test_event sys_cmn_pmu_hnf_cache_miss = {
 	.event = {
 		.name = "sys_cmn_pmu.hnf_cache_miss",
-		.event = "eventid=0x1,type=0x5",
+		.event = "eventid=1,type=5",
 		.desc = "Counts total cache misses in first lookup result (high priority)",
 		.topic = "uncore",
 		.pmu = "uncore_sys_cmn_pmu",
-- 
2.43.0.429.g432eaa2c6b-goog