nsys profile output kernel classifier (#9314)

Signed-off-by: Grace Ho <grho@nvidia.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Yineng Zhang <me@zhyncs.com>

examples/profiler/nsys_profile_tools/README.md

+# gputrc2graph.py
+
+This script processes NVIDIA Nsight Systems (`nsys`) GPU trace files
+(`.nsys-rep`) with -t cuda tracing enabled, and generates kernel-level
+summaries and visualizations of GPU and non-GPU time. It is useful for
+profiling and analyzing nsys profile output.
+
+## Usage
+
+### Command-line Arguments
+
+- `--in_file`
+  **(required)**
+  List of input files and their metadata. Each entry should be in the format:
+  `<nsys-rep>,<engine>,<model>,<elapsed_nonprofiled_sec>`
+  - `nsys-rep`: Path to the `.nsys-rep` file.
+  - `engine`: Engine name (e.g., `sglang`).
+  - `model`: Model name (e.g., `llama`, `gpt-oss`, `ds`).
+  - `elapsed_nonprofiled_sec`: Wall-clock runtime (in seconds) without
+    profiling. Specify `0` to use the elapsed time from the nsys-rep file
+    (this may inflate non-GPU time if actual runtime without profiling is
+    less). Multiple entries can be provided, separated by spaces.
+
+- `--out_dir`
+  Output directory for the generated CSV and HTML files.
+  If not specified, results are saved in the current directory.
+
+- `--title`
+  Title for the HTML chart/visualization.
+
+- `--nsys_cmd`
+  Path to the `nsys` command.
+  Default: `nsys` (assumes it is in your PATH).
+  Use this if `nsys` is not in your system PATH.
+
+## Notes
+
+- Make sure you have pandas installed. Any version is fine.
+- Make sure [nsys](https://developer.nvidia.com/nsight-systems/get-started) is
+installed, and specify the path to the `nsys` command with `--nsys_cmd` if it
+ is not in your PATH. The nsys version must be >= the nsys profile version that
+ was used to collect the traces when profiling the server, so that nsys can
+ process the nsys-rep that was generated.
+
+- For more details on available engines and models, see the help string in
+  the script or run:
+
+```bash
+python3 gputrc2graph.py --help
+```
+
+## Example 1: analyze a single profile
+
+To analyze the GPU cycles of for example, a llama-3.1-8B model with sglang:
+
+1. Run the following command to collect nsys profile, for sglang server config.
+
+   ```bash
+   nsys profile -t cuda -o nsys_res -f true --trace-fork-before-exec=true \
+   --cuda-graph-trace=node --delay <DELAY> --duration <DURATION> \
+   python3 -m sglang.launch_server --model meta-llama/Llama-3.1-8B ...
+   ```
+
+   where:
+
+   - DELAY: how many seconds to delay nsys from collecting profiles, needed so
+     that profiles aren't captured till sglang server has come up and load
+     generation starts.
+   - DURATION: how many seconds for nsys profile to run before generating the
+     profile. This should be > the duration of the run.
+2. After the server starts, run the client load generation command. Once the
+test completes, after DURATION amount of time, nsys profile will generate an
+nsys_res.nsys-rep file and shut down the server.
+
+3. Run step #1 again, this time starting up the server without collecting the
+profile.
+
+4. Run step #2 again, and record the total time to complete the test in
+seconds. This value will be used by the script to calculate the
+   CPU(non-GPU) seconds for the analysis.
+
+5. Say the run elapsed time from step #4 is 132 seconds. Run script to
+   analyze:
+
+   ```bash
+   python3 gputrc2graph.py \
+   --in_file run1.nsys-rep,sglang,llama,132
+   ```
+
+The command will produce 2 files for analysis:
+
+- result.html: this categorizes kernel names into different categories in a
+  stacked bar chart.
+- result.csv: shows how the kernel names are mapped to the different
+  categories.
+
+### HTML visualization with result.html
+
+The html file shows the number of elapsed seconds due to different GPU
+Substages or categories, which consist of attention kernels as the biggest
+category, at 63 seconds, followed by "gemm" kernels. This lets the user
+prioritize the kernels to focus on for performance optimizations.
+
+There's also an appended data table underneath the bar chart for copying out to
+ other post-processing tools.
+
+### Kernel to category mapping with result.csv
+
+Suppose the user would like to focus on improving triton kernels. It's not the
+biggest consumer of cycles at .01 sec but perhaps it hasn't been optimized.
+The next step is to use the result.csv to dive into what the kernels are which
+compose the triton kernel GPU cycles.
+
+## Example 2: analyze multiple profiles
+
+Suppose the user has multiple nsys trace files, captured for different models,
+say llama and gpt-oss in this case, and wish to compare their GPU/non-GPU
+time, something like the following command can be used.
+
+```bash
+python3 gputrc2graph.py \
+--in_file run1.nsys-rep,sglang,llama,100 run2.nsys-rep,sglang,gpt-oss,102 \
+--out_dir results
+```
+
+The analysis process is similar to example 1 but now there will be multiple
+stack bar charts that can be compared.  The categories for the different
+kernels will remain the same, so that it's easy to compare the GPU cycles for
+the same categories.
+
+Once a category is shown to have more cycles for one configuration than
+another, the next step would be to use the csv file to see what kernels are
+mapped into that category, and which kernels are taking the largest amount of
+time which would cause a difference for the overall category.
+
+## Example 3: add new classification for a new model
+
+To create a new engine DEF with model ABC, just add another json file in the same directory as
+gputrc2graph.py with the same format as the other json files. The script will automatically pick up all the json files in the same directory as engine/model specifications.
+
+Then, for this new model, suppose there are 4 kernels to be classified into
+"gemm" and "attn", where the gemm kernels have names with "*H*" or "*I*" in
+them, and attn kernels have names with "*J*" or "*K*" in them, just add another
+ .json file in the same directory as gputrc2graph.py with the same format as
+ the other json files, like the following:
+
+```json
+{
+  "DEF": {
+      "ABC": {
+          "H|I": "gemm",
+          "J|K": "attn",
+          "CUDA mem": "non-gpu-H_D_memops",
+          ".*": "misc"
+      }
+  }
+}
+```
+
+Each entry in the dictionary consists of:
+
+- key: a regex used to classify the kernels
+- value: the category to classify the kernels into.
+
+The last 2 entries are common for all engine/models, consisting of CUDA memory
+operations and a 'misc' for anything that's leftover and can't be classified.
+
+When invoking gputrc2graph.py, specify a trace file with this new model/engine
+like the following:
+
+```bash
+--in_file new.nsys-rep,DEF,ABC,<runtime>
+```
+
+If the engine_DEF.json file already exists, just add the model as a new node in
+ the existing engine file, after the other models.

examples/profiler/nsys_profile_tools/gputrc2graph.py

+"""
+    This generates gpu kernel analysis output from nsys rep. Will call nsys
+    stats  -r cuda_gpu_kern_trace, get non-overlapped gpu cycles, then generate
+    csv and html output for analysis
+"""
+
+import argparse
+import logging
+import os
+
+import regex as re
+
+logger = logging.getLogger(__name__)
+
+
+# helper data class for annotating kernels
+def load_engine_model():
+    """returns engine_model built from all json files in the current dir"""
+    import glob
+    import json
+
+    engine_model = {}
+
+    json_files = glob.glob(os.path.join(os.path.dirname(__file__) or ".", "*.json"))
+    for fname in json_files:
+        with open(fname, encoding="utf-8") as f:
+            engine_model.update(json.load(f))
+    return engine_model
+
+
+class GPUTrace2Graph:
+    """
+    Parses output of nsys report, generates csv and bar chart output
+    """
+
+    def __init__(self):
+        import pandas as pd  # avoid importing till needed
+
+        self.pd = pd
+        self.pd.options.mode.copy_on_write = True
+
+    # helper functions for generating trace->summary csvs
+    def gen_nonoverlapped_sum_from_gputrace(self, in_file, out_file):
+        logger.info("loading %s", in_file)
+        df = self.pd.read_csv(
+            in_file, usecols=["Start (ns)", "Duration (ns)", "Device", "Strm", "Name"]
+        )
+        df["End (ns)"] = df["Start (ns)"] + df["Duration (ns)"]
+        df = self.sum_non_overlapping_intervals(df)
+        # get ready to print table with elapsed times per kernel
+        df["Instances"] = 1
+        df_sum = df.groupby("Name", as_index=False).agg(
+            {"Elapsed Time (ns)": "sum", "Duration (ns)": "sum", "Instances": "size"}
+        )
+
+        # generate csv
+        df_sum["Total Time (sec)"] = df_sum["Duration (ns)"] / 1e9
+        df_sum["Elapsed Time (sec)"] = df_sum["Elapsed Time (ns)"] / 1e9
+        df_sum = df_sum.sort_values(by="Elapsed Time (sec)", ascending=False)
+        df_sum[["Elapsed Time (sec)", "Total Time (sec)", "Instances", "Name"]].to_csv(
+            out_file, index=False
+        )
+
+    def sum_non_overlapping_intervals(self, df):
+        """
+        returns new sorted df with Elapsed Time (ns) column using
+        vectorized operations
+        """
+        logger.info("sorting %s trace records by start time", str(df.shape))
+
+        # Sort by start time and reset index
+        df = df.sort_values(by="Start (ns)").reset_index(drop=True)
+
+        # Initialize elapsed time as duration
+        df["Elapsed Time (ns)"] = df["Duration (ns)"]
+
+        # Get numpy arrays for faster operations
+        starts = df["Start (ns)"].values
+        ends = df["End (ns)"].values
+
+        # Keep track of current interval end
+        current_end = ends[0]
+        display_units = max(1, int(len(df) / 100))
+        # Update current_end for overlapping intervals
+        for i in range(1, len(df)):
+            if i % display_units == 0:
+                print(f"processing trace: {int(i/len(df) * 100)} %", end="\r")
+            if starts[i] <= current_end:
+                if ends[i] > current_end:
+                    # Partial overlap
+                    df.iloc[i, df.columns.get_loc("Elapsed Time (ns)")] = (
+                        ends[i] - current_end
+                    )
+                    current_end = ends[i]
+                else:
+                    # Complete overlap
+                    df.iloc[i, df.columns.get_loc("Elapsed Time (ns)")] = 0
+            else:
+                # No overlap
+                current_end = ends[i]
+
+        return df
+
+    # functions for generating html files
+    def make_html(self, df, output_dir, title):
+        """make html graph from df"""
+        import plotly.express as px
+
+        if df.empty:
+            return
+        output_name = os.path.join(output_dir, "result")
+        if not title:
+            title = "Model_Engine"
+        x = "Model_Engine"
+        y = "Elapsed Time (sec)"
+        color = "Category"
+        """ generate kernel mapping table  """
+        # Sort Model_Engine categories by last field after underscore
+        df["Model_Engine"] = self.pd.Categorical(
+            df["Model_Engine"],
+            sorted(df["Model_Engine"].unique(), key=lambda x: x.split("_")[-1]),
+        )
+        df[["Model_Engine", color, "Instances", "Name", y]].sort_values(
+            by=color
+        ).to_csv(f"{output_name}.csv", index=False)
+        graph = px.histogram(
+            df.round(2),
+            x=x,
+            y=y,
+            title=(f"{y} for {title}"),
+            color=color,
+            text_auto=True,
+        )
+        # wrap x axis labels
+        graph.update_xaxes(automargin=True)
+        graph.write_html(f"{output_name}.html")
+        """
+            Generate data table with columns per Model_Engine into result.html
+        """
+        pivot_df = df.pivot_table(
+            values="Elapsed Time (sec)",
+            index="Category",
+            columns="Model_Engine",
+            aggfunc="sum",
+            observed=False,
+        ).round(2)
+        # Add sum row at bottom
+        pivot_df.loc["total_elapsed_sec"] = pivot_df.sum()
+        pivot_df.fillna("").to_html("temp.html")
+        with (
+            open(f"{output_name}.html", "a", encoding="utf-8") as outfile,
+            open("temp.html", encoding="utf-8") as infile,
+        ):
+            outfile.write(infile.read())
+        os.remove("temp.html")
+
+        print(
+            f"Finished generating: \n"
+            f" {output_name}.html for stack bar chart \n"
+            f" {output_name}.csv for Kernel-Category mapping"
+        )
+
+    def anno_gpu_kernname(self, df, mapping):
+        """add "Category" column"""
+
+        def anno_gpu_kernname_helper(name):
+            for kern_name, val in mapping.items():
+                if re.search(kern_name, name):
+                    return val
+
+        df["Category"] = df["Name"].apply(anno_gpu_kernname_helper)
+
+    def make_nongpu_row(self, df, nongpu_sec):
+        """this will append non-gpu time entry at end of df"""
+        nongpu_row = self.pd.DataFrame([df.iloc[-1]])
+        nongpu_row["Category"] = nongpu_row["Name"] = "CPU(non-GPU)"
+        nongpu_row["Instances"] = 1
+        nongpu_row["Elapsed Time (sec)"] = nongpu_sec
+        return nongpu_row
+
+    def is_valid_file(self, base_file):
+        """asserts if base_file is non-existent or is empty"""
+        assert (
+            os.path.isfile(base_file) and os.path.getsize(base_file) > 0
+        ), f"{base_file} doesn't exist or is empty"
+
+    def should_gen_file(self, new_file, base_file):
+        """figure out if new file should be generated from base_file"""
+        self.is_valid_file(base_file)
+        if (
+            os.path.exists(new_file)
+            and (os.path.getmtime(new_file) > os.path.getmtime(base_file))
+            and (os.path.getsize(base_file) > 0)
+        ):
+            logger.info("reusing %s", new_file)
+            return False
+        else:
+            logger.info("generating %s", new_file)
+            return True
+
+    def gen_sum_file(self, file, nsys_cmd):
+        """
+        generates sum file from nsys trace with times per kernel and
+        returns the name of the sum file
+        """
+        import subprocess
+
+        file_dir = os.path.dirname(file)
+        file_name = os.path.basename(file)
+
+        if not file_dir:
+            file_dir = "."
+        # Walk through trace and get the total non-overlapped time
+        nsys_stats_file = os.path.join(file_dir, f"{file_name}_cuda_gpu_trace.csv")
+        sum_file = os.path.join(file_dir, f"{file_name}_cuda_gpu_kernel_tracesum.csv")
+        if self.should_gen_file(nsys_stats_file, file):
+            cmd = [
+                nsys_cmd,
+                "stats",
+                "-r",
+                "cuda_gpu_trace",
+                file,
+                "-o",
+                f"{file_dir}/{file_name}",
+            ]
+            cmd_str = " ".join(cmd)
+            logger.info("+ %s", cmd_str)
+            # estimate time based on calibrated 240M/min
+            file_size_mb = os.path.getsize(file) / 1e6
+            logger.info(
+                "nsys stats for %.2f MB file expected to take %.2f min",
+                file_size_mb,
+                file_size_mb / 240,
+            )
+            try:
+                subprocess.run(cmd, check=True)
+            except (FileNotFoundError, subprocess.CalledProcessError) as e:
+                logger.error(
+                    "'%s' failed: %s. Use --nsys_cmd to specify nsys path", cmd_str, e
+                )
+                exit(1)
+            logger.info("generating non-overalapped sum %s", sum_file)
+            self.gen_nonoverlapped_sum_from_gputrace(nsys_stats_file, sum_file)
+        self.is_valid_file(sum_file)
+        logger.info("Finished generating %s", sum_file)
+        return sum_file
+
+    def gen_graph(self, in_file, out_dir, title, nsys_cmd, engine_model):
+        """generates graph and csv file from in_file into out_dir"""
+        # Initialize an empty DataFrame to store combined data
+        combined_df = self.pd.DataFrame()
+        for idx, (file, engine, model, total_sec) in enumerate(in_file):
+            file_dir = os.path.dirname(file)
+            file_name = os.path.basename(file)
+            if not file_dir:
+                file_dir = "."
+            sum_file = self.gen_sum_file(file, nsys_cmd)
+            # read kernel summary file
+            df = self.pd.read_csv(sum_file)
+            # annotate kernel to their categories
+            assert engine_model.get(engine), f"engine {engine} unknown"
+            assert engine_model[engine].get(model), f"model {model} unknown"
+            # remove nsys-rep from file_name for shorter x-label
+            file_name = file_name.replace(".nsys-rep", "")
+            df["Model_Engine"] = f"{model}_{engine}_{file_name}_{idx}"
+            self.anno_gpu_kernname(df, engine_model[engine][model])
+            # patch in non-gpu time
+            gpu_sec = round(df["Elapsed Time (sec)"].sum(), 1)
+            total_sec = round(float(total_sec), 1)
+            if total_sec < gpu_sec:
+                logger.warning(
+                    "Elapsed sec %.2f < GPU sec %.2f resetting Elapsed sec ",
+                    total_sec,
+                    gpu_sec,
+                )
+                total_sec = gpu_sec
+            nongpu_row = self.make_nongpu_row(df, total_sec - gpu_sec)
+            df = self.pd.concat([df, nongpu_row], ignore_index=True)
+            combined_df = self.pd.concat([combined_df, df], ignore_index=True)
+        if out_dir is None:
+            out_dir = "."
+        else:
+            os.makedirs(out_dir, exist_ok=True)
+        # generate html file
+        self.make_html(combined_df, out_dir, title)
+
+
+def parse_tuple(s):
+    return tuple(s.split(","))
+
+
+def main():
+    logging.basicConfig(
+        format=("%(asctime)s - %(levelname)s - %(message)s"), level=logging.INFO
+    )
+    parser = argparse.ArgumentParser(
+        description=(
+            "Process nsys rep and generate kernel non-overlapped cycles. \n"
+            "Example:\n"
+            "gputrc2graph.py --in_file d1.nsys-rep,sglang,llama,100 \n"
+            "d2.nsys-rep,sglang,gpt-oss,102 "
+            '--out_dir results/ --title "Model=gpt-oss SGLANG chart"'
+        ),
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+
+    # load supported engine_model
+    engine_model_supported = load_engine_model()
+    # Get a string representation of supported engine/model combinations
+    engine_model_supported_str = ", ".join(
+        f"{engine}:[{', '.join(models.keys())}]"
+        for engine, models in engine_model_supported.items()
+    )
+    parser.add_argument(
+        "--in_file",
+        type=parse_tuple,
+        nargs="+",
+        help=(
+            "list of (nsys-rep, engine, model, elapsed_nonprofiled_sec) "
+            "separated by space. Elapsed_nonprofiled_sec is runtime without "
+            "profiling used to calculate non-gpu time. Specify 0 to use "
+            "elapsed time from nsys-rep but that might inflate non-gpu time. "
+            f"Available engine:[model] are: {engine_model_supported_str} "
+            f"Example: --infile d1.nsys-rep,sglan,llama,100 "
+            "d2.nsys-rep,sglang,gpt-oss,102"
+        ),
+        required=True,
+    )
+    parser.add_argument("--out_dir", help=("output dir for result.csv/html"))
+    parser.add_argument("--title", help=("title for html chart"))
+    parser.add_argument(
+        "--nsys_cmd",
+        help=("nsys cmd, e.g. /usr/bin/nsys, Default: nsys"),
+        default="nsys",
+    )
+    args = parser.parse_args()
+    gputrace = GPUTrace2Graph()
+    gputrace.gen_graph(
+        args.in_file, args.out_dir, args.title, args.nsys_cmd, engine_model_supported
+    )
+
+
+if __name__ == "__main__":
+    main()

examples/profiler/nsys_profile_tools/sglang_engine_model.json

+{
+  "sglang": {
+    "llama": {
+      "gemm|nvjet": "gemm",
+      "fused_moe_kernel|GroupProblemShape|group_gemm_starts|bmm_|GemmUniversal": "moe_gemm",
+      "moe|sigmoid": "moe",
+      "CatArrayBatched|prepare_inputs": "prepare_next",
+      "ncclDevKernel|cross_device_reduce": "nccl_and_custom_ar",
+      "_norm_|Norm": "norm",
+      "topk": "topk",
+      "act_and_mul_": "activation",
+      "Rotary": "rope",
+      "SoftMax": "softmax",
+      "flash|fmha": "attn",
+      "elementwise": "elementwise",
+      "fp8_quant|cvt_|quantize": "quantize",
+      "reduce_kernel": "reduce",
+      "triton": "triton_kernel",
+      "CUDA mem": "non-gpu-H_D_memops",
+      ".*": "misc"
+    },
+    "ds": {
+      "block_fp8_matmul": "block_fp8_gemm",
+      "gemm|matmul|nvjet": "gemm",
+      "fused_moe_kernel": "moe_gemm",
+      "moe|expert|sigmoid": "moe",
+      "CatArrayBatched|write_req_to": "prepare_next",
+      "ncclDevKernel|cross_device_reduce|all_gather": "nccl_and_custom_ar",
+      "Norm": "norm",
+      "topk": "topk",
+      "activation|act_and_mul": "activation",
+      "compute_position_kernel": "rope",
+      "elementwise": "elementwise",
+      "fp8_quant|quant_fp8|quantize": "quantize",
+      "SoftMax": "softmax",
+      "reduce": "reduce",
+      "_fwd_|create_flash|::mla::|KVCache": "attn",
+      "CUDA mem": "non-gpu-H_D_memops",
+      ".*": "misc"
+    },
+    "gpt-oss": {
+      "gemm|nvjet": "gemm",
+      "fused_moe_kernel|_group_gemm|GroupProblemShape|GemmUniversal|bmm_|matmul_ogs_|_topk_forward|_combined_routing|_sum_bitmatrix_rows|_compute_writeback_idx": "moe_gemm",
+      "moe|sigmoid": "moe",
+      "CatArrayBatched|prepare_inputs": "prepare_next",
+      "_norm_|Norm": "norm",
+      "ncclDevKernel|cross_device_reduce|allreduce": "nccl_and_custom_ar",
+      "topk|TopK": "topk",
+      "act_and_mul_": "activation",
+      "Rotary": "rope",
+      "SoftMax": "softmax",
+      "flash|fmha": "attn",
+      "elementwise": "elementwise",
+      "fp8_quant|cvt_|quantize": "quantize",
+      "reduce_kernel": "reduce",
+      "triton": "triton_kernel",
+      "CUDA mem": "non-gpu-H_D_memops",
+      ".*": "misc"
+    }
+  }
+}