Fix boolean nested params, add dict format support, and enhance plotting for vllm bench sweep (#29025)

Signed-off-by: Luka Govedič <luka.govedic@gmail.com>
Signed-off-by: Luka Govedič <ProExpertProg@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: ProExpertProg <11367180+ProExpertProg@users.noreply.github.com>
Co-authored-by: Luka Govedič <luka.govedic@gmail.com>
Co-authored-by: Luka Govedič <ProExpertProg@users.noreply.github.com>

tests/benchmarks/test_param_sweep.py

@@ -0,0 +1,257 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import json
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from vllm.benchmarks.sweep.param_sweep import ParameterSweep, ParameterSweepItem
+
+
+class TestParameterSweepItem:
+    """Test ParameterSweepItem functionality."""
+
+    @pytest.mark.parametrize(
+        "input_dict,expected",
+        [
+            (
+                {"compilation_config.use_inductor_graph_partition": False},
+                "--compilation-config.use_inductor_graph_partition=false",
+            ),
+            (
+                {"compilation_config.use_inductor_graph_partition": True},
+                "--compilation-config.use_inductor_graph_partition=true",
+            ),
+            (
+                {"compilation_config.use_inductor": False},
+                "--compilation-config.use_inductor=false",
+            ),
+            (
+                {"compilation_config.use_inductor": True},
+                "--compilation-config.use_inductor=true",
+            ),
+        ],
+    )
+    def test_nested_boolean_params(self, input_dict, expected):
+        """Test that nested boolean params use =true/false syntax."""
+        item = ParameterSweepItem.from_record(input_dict)
+        cmd = item.apply_to_cmd(["vllm", "serve", "model"])
+        assert expected in cmd
+
+    @pytest.mark.parametrize(
+        "input_dict,expected",
+        [
+            ({"enable_prefix_caching": False}, "--no-enable-prefix-caching"),
+            ({"enable_prefix_caching": True}, "--enable-prefix-caching"),
+            ({"disable_log_stats": False}, "--no-disable-log-stats"),
+            ({"disable_log_stats": True}, "--disable-log-stats"),
+        ],
+    )
+    def test_non_nested_boolean_params(self, input_dict, expected):
+        """Test that non-nested boolean params use --no- prefix."""
+        item = ParameterSweepItem.from_record(input_dict)
+        cmd = item.apply_to_cmd(["vllm", "serve", "model"])
+        assert expected in cmd
+
+    @pytest.mark.parametrize(
+        "compilation_config",
+        [
+            {"cudagraph_mode": "full", "mode": 2, "use_inductor_graph_partition": True},
+            {
+                "cudagraph_mode": "piecewise",
+                "mode": 3,
+                "use_inductor_graph_partition": False,
+            },
+        ],
+    )
+    def test_nested_dict_value(self, compilation_config):
+        """Test that nested dict values are serialized as JSON."""
+        item = ParameterSweepItem.from_record(
+            {"compilation_config": compilation_config}
+        )
+        cmd = item.apply_to_cmd(["vllm", "serve", "model"])
+        assert "--compilation-config" in cmd
+        # The dict should be JSON serialized
+        idx = cmd.index("--compilation-config")
+        assert json.loads(cmd[idx + 1]) == compilation_config
+
+    @pytest.mark.parametrize(
+        "input_dict,expected_key,expected_value",
+        [
+            ({"model": "test-model"}, "--model", "test-model"),
+            ({"max_tokens": 100}, "--max-tokens", "100"),
+            ({"temperature": 0.7}, "--temperature", "0.7"),
+        ],
+    )
+    def test_string_and_numeric_values(self, input_dict, expected_key, expected_value):
+        """Test that string and numeric values are handled correctly."""
+        item = ParameterSweepItem.from_record(input_dict)
+        cmd = item.apply_to_cmd(["vllm", "serve"])
+        assert expected_key in cmd
+        assert expected_value in cmd
+
+    @pytest.mark.parametrize(
+        "input_dict,expected_key,key_idx_offset",
+        [
+            ({"max_tokens": 200}, "--max-tokens", 1),
+            ({"enable_prefix_caching": False}, "--no-enable-prefix-caching", 0),
+        ],
+    )
+    def test_replace_existing_parameter(self, input_dict, expected_key, key_idx_offset):
+        """Test that existing parameters in cmd are replaced."""
+        item = ParameterSweepItem.from_record(input_dict)
+
+        if key_idx_offset == 1:
+            # Key-value pair
+            cmd = item.apply_to_cmd(["vllm", "serve", "--max-tokens", "100", "model"])
+            assert expected_key in cmd
+            idx = cmd.index(expected_key)
+            assert cmd[idx + 1] == "200"
+            assert "100" not in cmd
+        else:
+            # Boolean flag
+            cmd = item.apply_to_cmd(
+                ["vllm", "serve", "--enable-prefix-caching", "model"]
+            )
+            assert expected_key in cmd
+            assert "--enable-prefix-caching" not in cmd
+
+
+class TestParameterSweep:
+    """Test ParameterSweep functionality."""
+
+    def test_from_records_list(self):
+        """Test creating ParameterSweep from a list of records."""
+        records = [
+            {"max_tokens": 100, "temperature": 0.7},
+            {"max_tokens": 200, "temperature": 0.9},
+        ]
+        sweep = ParameterSweep.from_records(records)
+        assert len(sweep) == 2
+        assert sweep[0]["max_tokens"] == 100
+        assert sweep[1]["max_tokens"] == 200
+
+    def test_read_from_dict(self):
+        """Test creating ParameterSweep from a dict format."""
+        data = {
+            "experiment1": {"max_tokens": 100, "temperature": 0.7},
+            "experiment2": {"max_tokens": 200, "temperature": 0.9},
+        }
+        sweep = ParameterSweep.read_from_dict(data)
+        assert len(sweep) == 2
+
+        # Check that items have the _benchmark_name field
+        names = {item["_benchmark_name"] for item in sweep}
+        assert names == {"experiment1", "experiment2"}
+
+        # Check that parameters are preserved
+        for item in sweep:
+            if item["_benchmark_name"] == "experiment1":
+                assert item["max_tokens"] == 100
+                assert item["temperature"] == 0.7
+            elif item["_benchmark_name"] == "experiment2":
+                assert item["max_tokens"] == 200
+                assert item["temperature"] == 0.9
+
+    def test_read_json_list_format(self):
+        """Test reading JSON file with list format."""
+        records = [
+            {"max_tokens": 100, "temperature": 0.7},
+            {"max_tokens": 200, "temperature": 0.9},
+        ]
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(records, f)
+            temp_path = Path(f.name)
+
+        try:
+            sweep = ParameterSweep.read_json(temp_path)
+            assert len(sweep) == 2
+            assert sweep[0]["max_tokens"] == 100
+            assert sweep[1]["max_tokens"] == 200
+        finally:
+            temp_path.unlink()
+
+    def test_read_json_dict_format(self):
+        """Test reading JSON file with dict format."""
+        data = {
+            "experiment1": {"max_tokens": 100, "temperature": 0.7},
+            "experiment2": {"max_tokens": 200, "temperature": 0.9},
+        }
+
+        with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+            json.dump(data, f)
+            temp_path = Path(f.name)
+
+        try:
+            sweep = ParameterSweep.read_json(temp_path)
+            assert len(sweep) == 2
+
+            # Check that items have the _benchmark_name field
+            names = {item["_benchmark_name"] for item in sweep}
+            assert names == {"experiment1", "experiment2"}
+        finally:
+            temp_path.unlink()
+
+    def test_unique_benchmark_names_validation(self):
+        """Test that duplicate _benchmark_name values raise an error."""
+        # Test with duplicate names in list format
+        records = [
+            {"_benchmark_name": "exp1", "max_tokens": 100},
+            {"_benchmark_name": "exp1", "max_tokens": 200},
+        ]
+
+        with pytest.raises(ValueError, match="Duplicate _benchmark_name values"):
+            ParameterSweep.from_records(records)
+
+    def test_unique_benchmark_names_multiple_duplicates(self):
+        """Test validation with multiple duplicate names."""
+        records = [
+            {"_benchmark_name": "exp1", "max_tokens": 100},
+            {"_benchmark_name": "exp1", "max_tokens": 200},
+            {"_benchmark_name": "exp2", "max_tokens": 300},
+            {"_benchmark_name": "exp2", "max_tokens": 400},
+        ]
+
+        with pytest.raises(ValueError, match="Duplicate _benchmark_name values"):
+            ParameterSweep.from_records(records)
+
+    def test_no_benchmark_names_allowed(self):
+        """Test that records without _benchmark_name are allowed."""
+        records = [
+            {"max_tokens": 100, "temperature": 0.7},
+            {"max_tokens": 200, "temperature": 0.9},
+        ]
+        sweep = ParameterSweep.from_records(records)
+        assert len(sweep) == 2
+
+    def test_mixed_benchmark_names_allowed(self):
+        """Test that mixing records with and without _benchmark_name is allowed."""
+        records = [
+            {"_benchmark_name": "exp1", "max_tokens": 100},
+            {"max_tokens": 200, "temperature": 0.9},
+        ]
+        sweep = ParameterSweep.from_records(records)
+        assert len(sweep) == 2
+
+
+class TestParameterSweepItemKeyNormalization:
+    """Test key normalization in ParameterSweepItem."""
+
+    def test_underscore_to_hyphen_conversion(self):
+        """Test that underscores are converted to hyphens in CLI."""
+        item = ParameterSweepItem.from_record({"max_tokens": 100})
+        cmd = item.apply_to_cmd(["vllm", "serve"])
+        assert "--max-tokens" in cmd
+
+    def test_nested_key_preserves_suffix(self):
+        """Test that nested keys preserve the suffix format."""
+        # The suffix after the dot should preserve underscores
+        item = ParameterSweepItem.from_record(
+            {"compilation_config.some_nested_param": "value"}
+        )
+        cmd = item.apply_to_cmd(["vllm", "serve"])
+        # The prefix (compilation_config) gets converted to hyphens,
+        # but the suffix (some_nested_param) is preserved
+        assert any("compilation-config.some_nested_param" in arg for arg in cmd)

tests/benchmarks/test_plot_filters.py

@@ -0,0 +1,171 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import pandas as pd
+import pytest
+
+from vllm.benchmarks.sweep.plot import (
+    PlotEqualTo,
+    PlotFilterBase,
+    PlotFilters,
+    PlotGreaterThan,
+    PlotGreaterThanOrEqualTo,
+    PlotLessThan,
+    PlotLessThanOrEqualTo,
+    PlotNotEqualTo,
+)
+
+
+class TestPlotFilters:
+    """Test PlotFilter functionality including 'inf' edge case."""
+
+    def setup_method(self):
+        """Create sample DataFrames for testing."""
+        # DataFrame with numeric values
+        self.df_numeric = pd.DataFrame(
+            {
+                "request_rate": [1.0, 5.0, 10.0, 50.0, 100.0],
+                "value": [10, 20, 30, 40, 50],
+            }
+        )
+
+        # DataFrame with float('inf') - note: string "inf" values are coerced
+        # to float when loading data, so we only test with float('inf')
+        self.df_inf_float = pd.DataFrame(
+            {
+                "request_rate": [1.0, 5.0, 10.0, float("inf"), float("inf")],
+                "value": [10, 20, 30, 40, 50],
+            }
+        )
+
+    @pytest.mark.parametrize(
+        "target,expected_count",
+        [
+            ("5.0", 1),
+            ("10.0", 1),
+            ("1.0", 1),
+        ],
+    )
+    def test_equal_to_numeric(self, target, expected_count):
+        """Test PlotEqualTo with numeric values."""
+        filter_obj = PlotEqualTo("request_rate", target)
+        result = filter_obj.apply(self.df_numeric)
+        assert len(result) == expected_count
+
+    def test_equal_to_inf_float(self):
+        """Test PlotEqualTo with float('inf')."""
+        filter_obj = PlotEqualTo("request_rate", "inf")
+        result = filter_obj.apply(self.df_inf_float)
+        # Should match both float('inf') entries because float('inf') == float('inf')
+        assert len(result) == 2
+
+    @pytest.mark.parametrize(
+        "target,expected_count",
+        [
+            ("5.0", 4),  # All except 5.0
+            ("1.0", 4),  # All except 1.0
+        ],
+    )
+    def test_not_equal_to_numeric(self, target, expected_count):
+        """Test PlotNotEqualTo with numeric values."""
+        filter_obj = PlotNotEqualTo("request_rate", target)
+        result = filter_obj.apply(self.df_numeric)
+        assert len(result) == expected_count
+
+    def test_not_equal_to_inf_float(self):
+        """Test PlotNotEqualTo with float('inf')."""
+        filter_obj = PlotNotEqualTo("request_rate", "inf")
+        result = filter_obj.apply(self.df_inf_float)
+        # Should exclude float('inf') entries
+        assert len(result) == 3
+
+    @pytest.mark.parametrize(
+        "target,expected_count",
+        [
+            ("10.0", 2),  # 1.0, 5.0
+            ("50.0", 3),  # 1.0, 5.0, 10.0
+            ("5.0", 1),  # 1.0
+        ],
+    )
+    def test_less_than(self, target, expected_count):
+        """Test PlotLessThan with numeric values."""
+        filter_obj = PlotLessThan("request_rate", target)
+        result = filter_obj.apply(self.df_numeric)
+        assert len(result) == expected_count
+
+    @pytest.mark.parametrize(
+        "target,expected_count",
+        [
+            ("10.0", 3),  # 1.0, 5.0, 10.0
+            ("5.0", 2),  # 1.0, 5.0
+        ],
+    )
+    def test_less_than_or_equal_to(self, target, expected_count):
+        """Test PlotLessThanOrEqualTo with numeric values."""
+        filter_obj = PlotLessThanOrEqualTo("request_rate", target)
+        result = filter_obj.apply(self.df_numeric)
+        assert len(result) == expected_count
+
+    @pytest.mark.parametrize(
+        "target,expected_count",
+        [
+            ("10.0", 2),  # 50.0, 100.0
+            ("5.0", 3),  # 10.0, 50.0, 100.0
+        ],
+    )
+    def test_greater_than(self, target, expected_count):
+        """Test PlotGreaterThan with numeric values."""
+        filter_obj = PlotGreaterThan("request_rate", target)
+        result = filter_obj.apply(self.df_numeric)
+        assert len(result) == expected_count
+
+    @pytest.mark.parametrize(
+        "target,expected_count",
+        [
+            ("10.0", 3),  # 10.0, 50.0, 100.0
+            ("5.0", 4),  # 5.0, 10.0, 50.0, 100.0
+        ],
+    )
+    def test_greater_than_or_equal_to(self, target, expected_count):
+        """Test PlotGreaterThanOrEqualTo with numeric values."""
+        filter_obj = PlotGreaterThanOrEqualTo("request_rate", target)
+        result = filter_obj.apply(self.df_numeric)
+        assert len(result) == expected_count
+
+    @pytest.mark.parametrize(
+        "filter_str,expected_var,expected_target,expected_type",
+        [
+            ("request_rate==5.0", "request_rate", "5.0", PlotEqualTo),
+            ("request_rate!=10.0", "request_rate", "10.0", PlotNotEqualTo),
+            ("request_rate<50.0", "request_rate", "50.0", PlotLessThan),
+            ("request_rate<=50.0", "request_rate", "50.0", PlotLessThanOrEqualTo),
+            ("request_rate>10.0", "request_rate", "10.0", PlotGreaterThan),
+            ("request_rate>=10.0", "request_rate", "10.0", PlotGreaterThanOrEqualTo),
+            ("request_rate==inf", "request_rate", "inf", PlotEqualTo),
+            ("request_rate!='inf'", "request_rate", "inf", PlotNotEqualTo),
+        ],
+    )
+    def test_parse_str(self, filter_str, expected_var, expected_target, expected_type):
+        """Test parsing filter strings."""
+        filter_obj = PlotFilterBase.parse_str(filter_str)
+        assert isinstance(filter_obj, expected_type)
+        assert filter_obj.var == expected_var
+        assert filter_obj.target == expected_target
+
+    def test_parse_str_inf_edge_case(self):
+        """Test parsing 'inf' string in filter."""
+        filter_obj = PlotFilterBase.parse_str("request_rate==inf")
+        assert isinstance(filter_obj, PlotEqualTo)
+        assert filter_obj.var == "request_rate"
+        assert filter_obj.target == "inf"
+
+    def test_parse_multiple_filters(self):
+        """Test parsing multiple filters."""
+        filters = PlotFilters.parse_str("request_rate>5.0,value<=40")
+        assert len(filters) == 2
+        assert isinstance(filters[0], PlotGreaterThan)
+        assert isinstance(filters[1], PlotLessThanOrEqualTo)
+
+    def test_parse_empty_filter(self):
+        """Test parsing empty filter string."""
+        filters = PlotFilters.parse_str("")
+        assert len(filters) == 0

vllm/benchmarks/sweep/param_sweep.py

@@ -9,8 +9,26 @@ class ParameterSweep(list["ParameterSweepItem"]):
     @classmethod
     def read_json(cls, filepath: os.PathLike):
         with open(filepath, "rb") as f:
-            records = json.load(f)
+            data = json.load(f)
 
+        # Support both list and dict formats
+        if isinstance(data, dict):
+            return cls.read_from_dict(data)
+
+        return cls.from_records(data)
+
+    @classmethod
+    def read_from_dict(cls, data: dict[str, dict[str, object]]):
+        """
+        Read parameter sweep from a dict format where keys are names.
+
+        Example:
+            {
+                "experiment1": {"max_tokens": 100, "temperature": 0.7},
+                "experiment2": {"max_tokens": 200, "temperature": 0.9}
+            }
+        """
+        records = [{"_benchmark_name": name, **params} for name, params in data.items()]
         return cls.from_records(records)
 
     @classmethod
@@ -21,6 +39,15 @@ class ParameterSweep(list["ParameterSweepItem"]):
                 f"but found type: {type(records)}"
             )
 
+        # Validate that all _benchmark_name values are unique if provided
+        names = [r["_benchmark_name"] for r in records if "_benchmark_name" in r]
+        if names and len(names) != len(set(names)):
+            duplicates = [name for name in names if names.count(name) > 1]
+            raise ValueError(
+                f"Duplicate _benchmark_name values found: {set(duplicates)}. "
+                f"All _benchmark_name values must be unique."
+            )
+
         return cls(ParameterSweepItem.from_record(record) for record in records)
 
 
@@ -38,6 +65,18 @@ class ParameterSweepItem(dict[str, object]):
     def __or__(self, other: dict[str, Any]):
         return type(self)(super().__or__(other))
 
+    @property
+    def name(self) -> str:
+        """
+        Get the name for this parameter sweep item.
+
+        Returns the '_benchmark_name' field if present, otherwise returns a text
+        representation of all parameters.
+        """
+        if "_benchmark_name" in self:
+            return self["_benchmark_name"]
+        return self.as_text(sep="-")
+
     # In JSON, we prefer "_"
     def _iter_param_key_candidates(self, param_key: str):
         # Inner config arguments are not converted by the CLI
@@ -63,29 +102,57 @@ class ParameterSweepItem(dict[str, object]):
     def has_param(self, param_key: str) -> bool:
         return any(k in self for k in self._iter_param_key_candidates(param_key))
 
+    def _normalize_cmd_kv_pair(self, k: str, v: object) -> list[str]:
+        """
+        Normalize a key-value pair into command-line arguments.
+
+        Returns a list containing either:
+        - A single element for boolean flags (e.g., ['--flag'] or ['--flag=true'])
+        - Two elements for key-value pairs (e.g., ['--key', 'value'])
+        """
+        if isinstance(v, bool):
+            # For nested params (containing "."), use =true/false syntax
+            if "." in k:
+                return [f"{self._normalize_cmd_key(k)}={'true' if v else 'false'}"]
+            else:
+                return [self._normalize_cmd_key(k if v else "no-" + k)]
+        else:
+            return [self._normalize_cmd_key(k), str(v)]
+
     def apply_to_cmd(self, cmd: list[str]) -> list[str]:
         cmd = list(cmd)
 
         for k, v in self.items():
+            # Skip the '_benchmark_name' field, not a parameter
+            if k == "_benchmark_name":
+                continue
+
+            # Serialize dict values as JSON
+            if isinstance(v, dict):
+                v = json.dumps(v)
+
             for k_candidate in self._iter_cmd_key_candidates(k):
                 try:
                     k_idx = cmd.index(k_candidate)
 
-                    if isinstance(v, bool):
+                    # Replace existing parameter
-                        cmd[k_idx] = self._normalize_cmd_key(k if v else "no-" + k)
+                    normalized = self._normalize_cmd_kv_pair(k, v)
+                    if len(normalized) == 1:
+                        # Boolean flag
+                        cmd[k_idx] = normalized[0]
                     else:
-                        cmd[k_idx + 1] = str(v)
+                        # Key-value pair
+                        cmd[k_idx] = normalized[0]
+                        cmd[k_idx + 1] = normalized[1]
 
                     break
                 except ValueError:
                     continue
             else:
-                if isinstance(v, bool):
+                # Add new parameter
-                    cmd.append(self._normalize_cmd_key(k if v else "no-" + k))
+                cmd.extend(self._normalize_cmd_kv_pair(k, v))
-                else:
-                    cmd.extend([self._normalize_cmd_key(k), str(v)])
 
         return cmd
 
     def as_text(self, sep: str = ", ") -> str:
-        return sep.join(f"{k}={v}" for k, v in self.items())
+        return sep.join(f"{k}={v}" for k, v in self.items() if k != "_benchmark_name")

vllm/benchmarks/sweep/plot.py

@@ -65,6 +65,18 @@ class PlotEqualTo(PlotFilterBase):
         return df[df[self.var] == target]
 
 
+@dataclass
+class PlotNotEqualTo(PlotFilterBase):
+    @override
+    def apply(self, df: "pd.DataFrame") -> "pd.DataFrame":
+        try:
+            target = float(self.target)
+        except ValueError:
+            target = self.target
+
+        return df[df[self.var] != target]
+
+
 @dataclass
 class PlotLessThan(PlotFilterBase):
     @override
@@ -96,6 +108,7 @@ class PlotGreaterThanOrEqualTo(PlotFilterBase):
 # NOTE: The ordering is important! Match longer op_keys first
 PLOT_FILTERS: dict[str, type[PlotFilterBase]] = {
     "==": PlotEqualTo,
+    "!=": PlotNotEqualTo,
     "<=": PlotLessThanOrEqualTo,
     ">=": PlotGreaterThanOrEqualTo,
     "<": PlotLessThan,
@@ -167,6 +180,27 @@ def _json_load_bytes(path: Path) -> list[dict[str, object]]:
         return json.load(f)
 
 
+def _convert_inf_nan_strings(data: list[dict[str, object]]) -> list[dict[str, object]]:
+    """
+    Convert string values "inf", "-inf", and "nan" to their float equivalents.
+
+    This handles the case where JSON serialization represents inf/nan as strings.
+    """
+    converted_data = []
+    for record in data:
+        converted_record = {}
+        for key, value in record.items():
+            if isinstance(value, str):
+                if value in ["inf", "-inf", "nan"]:
+                    converted_record[key] = float(value)
+                else:
+                    converted_record[key] = value
+            else:
+                converted_record[key] = value
+        converted_data.append(converted_record)
+    return converted_data
+
+
 def _get_metric(run_data: dict[str, object], metric_key: str):
     try:
         return run_data[metric_key]
@@ -178,12 +212,15 @@ def _get_group(run_data: dict[str, object], group_keys: list[str]):
     return tuple((k, str(_get_metric(run_data, k))) for k in group_keys)
 
 
-def _get_fig_path(fig_dir: Path, group: tuple[tuple[str, str], ...]):
+def _get_fig_path(fig_dir: Path, group: tuple[tuple[str, str], ...], fig_name: str):
     parts = list[str]()
+
+    # Start with figure name (always provided, defaults to "FIGURE")
+    parts.append(fig_name)
+
+    # Always append group data if present
     if group:
-        parts.extend(("FIGURE-", *(f"{k}={v}" for k, v in group)))
+        parts.extend(f"{k}={v}" for k, v in group)
-    else:
-        parts.append("figure")
 
     return fig_dir / sanitize_filename("-".join(parts) + ".png")
 
@@ -217,6 +254,10 @@ def _plot_fig(
     scale_x: str | None,
     scale_y: str | None,
     dry_run: bool,
+    fig_name: str,
+    error_bars: bool,
+    fig_height: float,
+    fig_dpi: int,
 ):
     fig_group, fig_data = fig_group_data
 
@@ -230,7 +271,7 @@ def _plot_fig(
         for _, row_data in row_groups
     )
 
-    fig_path = _get_fig_path(fig_dir, fig_group)
+    fig_path = _get_fig_path(fig_dir, fig_group, fig_name)
 
     print("[BEGIN FIGURE]")
     print(f"Group: {dict(fig_group)}")
@@ -241,6 +282,8 @@ def _plot_fig(
         print("[END FIGURE]")
         return
 
+    # Convert string "inf", "-inf", and "nan" to their float equivalents
+    fig_data = _convert_inf_nan_strings(fig_data)
     df = pd.DataFrame.from_records(fig_data)
 
     if var_x not in df.columns:
@@ -275,6 +318,10 @@ def _plot_fig(
     df = filter_by.apply(df)
     df = bin_by.apply(df)
 
+    # Sort by curve_by columns alphabetically for consistent legend ordering
+    if curve_by:
+        df = df.sort_values(by=curve_by)
+
     df["row_group"] = (
         pd.concat(
             [k + "=" + df[k].astype(str) for k in row_by],
@@ -293,7 +340,7 @@ def _plot_fig(
         else "(All)"
     )
 
-    g = sns.FacetGrid(df, row="row_group", col="col_group")
+    g = sns.FacetGrid(df, row="row_group", col="col_group", height=fig_height)
 
     if row_by and col_by:
         g.set_titles("{row_name}\n{col_name}")
@@ -320,6 +367,7 @@ def _plot_fig(
             style=style,
             size=size,
             markers=True,
+            errorbar="sd" if error_bars else None,
         )
 
         g.add_legend(title=hue)
@@ -339,11 +387,12 @@ def _plot_fig(
             y=var_y,
             hue="curve_group",
             markers=True,
+            errorbar="sd" if error_bars else None,
         )
 
         g.add_legend()
 
-    g.savefig(fig_path)
+    g.savefig(fig_path, dpi=fig_dpi)
     plt.close(g.figure)
 
     print("[END FIGURE]")
@@ -364,6 +413,10 @@ def plot(
     scale_x: str | None,
     scale_y: str | None,
     dry_run: bool,
+    fig_name: str = "FIGURE",
+    error_bars: bool = True,
+    fig_height: float = 6.4,
+    fig_dpi: int = 300,
 ):
     all_data = [
         run_data
@@ -398,6 +451,10 @@ def plot(
                     scale_x=scale_x,
                     scale_y=scale_y,
                     dry_run=dry_run,
+                    fig_name=fig_name,
+                    error_bars=error_bars,
+                    fig_height=fig_height,
+                    fig_dpi=fig_dpi,
                 ),
                 fig_groups,
             )
@@ -419,6 +476,10 @@ class SweepPlotArgs:
     scale_x: str | None
     scale_y: str | None
     dry_run: bool
+    fig_name: str = "FIGURE"
+    error_bars: bool = True
+    fig_height: float = 6.4
+    fig_dpi: int = 300
 
     parser_name: ClassVar[str] = "plot"
     parser_help: ClassVar[str] = "Plot performance curves from parameter sweep results."
@@ -448,6 +509,10 @@ class SweepPlotArgs:
             scale_x=args.scale_x,
             scale_y=args.scale_y,
             dry_run=args.dry_run,
+            fig_name=args.fig_name,
+            error_bars=not args.no_error_bars,
+            fig_height=args.fig_height,
+            fig_dpi=args.fig_dpi,
         )
 
     @classmethod
@@ -541,6 +606,32 @@ class SweepPlotArgs:
             "Currently only accepts string values such as 'log' and 'sqrt'. "
             "See also: https://seaborn.pydata.org/generated/seaborn.objects.Plot.scale.html",
         )
+        parser.add_argument(
+            "--fig-name",
+            type=str,
+            default="FIGURE",
+            help="Name prefix for the output figure file. "
+            "Group data is always appended when present. "
+            "Default: 'FIGURE'. Example: --fig-name my_performance_plot",
+        )
+        parser.add_argument(
+            "--no-error-bars",
+            action="store_true",
+            help="If set, disables error bars on the plot. "
+            "By default, error bars are shown.",
+        )
+        parser.add_argument(
+            "--fig-height",
+            type=float,
+            default=6.4,
+            help="Height of each subplot in inches. Default: 6.4",
+        )
+        parser.add_argument(
+            "--fig-dpi",
+            type=int,
+            default=300,
+            help="Resolution of the output figure in dots per inch. Default: 300",
+        )
         parser.add_argument(
             "--dry-run",
             action="store_true",
@@ -566,6 +657,10 @@ def run_main(args: SweepPlotArgs):
         scale_x=args.scale_x,
         scale_y=args.scale_y,
         dry_run=args.dry_run,
+        fig_name=args.fig_name,
+        error_bars=args.error_bars,
+        fig_height=args.fig_height,
+        fig_dpi=args.fig_dpi,
     )
 
 

vllm/benchmarks/sweep/serve.py

@@ -138,9 +138,9 @@ def _get_comb_base_path(
 ):
     parts = list[str]()
     if serve_comb:
-        parts.extend(("SERVE-", serve_comb.as_text(sep="-")))
+        parts.extend(("SERVE-", serve_comb.name))
     if bench_comb:
-        parts.extend(("BENCH-", bench_comb.as_text(sep="-")))
+        parts.extend(("BENCH-", bench_comb.name))
 
     return output_dir / sanitize_filename("-".join(parts))
 
@@ -345,8 +345,9 @@ class SweepServeArgs:
             "--serve-params",
             type=str,
             default=None,
-            help="Path to JSON file containing a list of parameter combinations "
+            help="Path to JSON file containing parameter combinations "
-            "for the `vllm serve` command. "
+            "for the `vllm serve` command. Can be either a list of dicts or a dict "
+            "where keys are benchmark names. "
             "If both `serve_params` and `bench_params` are given, "
             "this script will iterate over their Cartesian product.",
         )
@@ -354,8 +355,9 @@ class SweepServeArgs:
             "--bench-params",
             type=str,
             default=None,
-            help="Path to JSON file containing a list of parameter combinations "
+            help="Path to JSON file containing parameter combinations "
-            "for the `vllm bench serve` command. "
+            "for the `vllm bench serve` command. Can be either a list of dicts or "
+            "a dict where keys are benchmark names. "
             "If both `serve_params` and `bench_params` are given, "
             "this script will iterate over their Cartesian product.",
         )