Performance Profiling and Debugging with cuml.accel#
This notebook demonstrates how to use the profiling capabilities in cuml.accel to understand which operations are being accelerated on GPU and which are falling back to CPU execution. This can be particularly useful for debugging performance issues or understanding why certain operations might not be accelerated.
cuml.accel provides two types of profilers:
Function Profiler: Shows statistics about potentially accelerated function and method calls
Line Profiler: Shows per-line statistics on your script with GPU utilization percentages
Let’s explore both profilers with practical examples.
Setup#
First, let’s load the cuml.accel extension and import the necessary libraries.
[1]:
# Load the cuml.accel extension
%load_ext cuml.accel
[2]:
from sklearn.linear_model import Ridge
from sklearn.datasets import make_regression
from sklearn.ensemble import RandomForestClassifier
from sklearn.model_selection import train_test_split
Function Profiler#
The function profiler gathers statistics about potentially accelerated function and method calls. It can show:
Which method calls
cuml.accelhad the potential to accelerateWhich methods were accelerated on GPU, and their total runtime
Which methods required a CPU fallback, their total runtime, and why a fallback was needed
Example 1: Ridge Regression with Mixed GPU/CPU Execution#
Let’s start with a simple example that demonstrates both GPU acceleration and CPU fallback using Ridge regression.
[3]:
# Generate sample data
X, y = make_regression(n_samples=1000, n_features=100, noise=0.1, random_state=42)
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)
[4]:
%%cuml.accel.profile
# Fit and predict on GPU (supported parameters)
ridge = Ridge(alpha=1.0)
ridge.fit(X_train, y_train)
predictions_gpu = ridge.predict(X_test)
# Retry, using a hyperparameter that isn't supported on GPU
ridge_cpu = Ridge(positive=True) # positive=True is not supported on GPU
ridge_cpu.fit(X_train, y_train)
predictions_cpu = ridge_cpu.predict(X_test)
cuml.accel profile ┏━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━┓ ┃ Function ┃ GPU calls ┃ GPU time ┃ CPU calls ┃ CPU time ┃ ┡━━━━━━━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━┩ │ Ridge.fit │ 1 │ 109.5ms │ 1 │ 4.1ms │ │ Ridge.predict │ 1 │ 2.1ms │ 1 │ 147.8µs │ ├───────────────┼───────────┼──────────┼───────────┼──────────┤ │ Total │ 2 │ 111.6ms │ 2 │ 4.2ms │ └───────────────┴───────────┴──────────┴───────────┴──────────┘ Not all operations ran on the GPU. The following functions required CPU fallback for the following reasons: * Ridge.fit - `positive=True` is not supported * Ridge.predict - Estimator not fit on GPU
The function profiler output above shows:
GPU calls: Methods that ran successfully on GPU
GPU time: Total time spent on GPU operations
CPU calls: Methods that fell back to CPU execution
CPU time: Total time spent on CPU operations
Fallback reasons: Why certain operations couldn’t run on GPU
Example 2: Random Forest Classification#
Let’s try a more complex example with Random Forest classification.
[5]:
# Generate classification data
from sklearn.datasets import make_classification
X_class, y_class = make_classification(n_samples=2000, n_features=20, n_informative=15,
n_redundant=5, n_classes=3, random_state=42)
X_train_class, X_test_class, y_train_class, y_test_class = train_test_split(
X_class, y_class, test_size=0.2, random_state=42)
[6]:
%%cuml.accel.profile
# Random Forest with supported parameters
rf = RandomForestClassifier(n_estimators=100, max_depth=10, random_state=42)
rf.fit(X_train_class, y_train_class)
rf_predictions = rf.predict(X_test_class)
rf_probabilities = rf.predict_proba(X_test_class)
cuml.accel profile ┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━┓ ┃ Function ┃ GPU calls ┃ GPU time ┃ CPU calls ┃ CPU time ┃ ┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━┩ │ RandomForestClassifier.fit │ 1 │ 390.3ms │ 0 │ 0s │ │ RandomForestClassifier.predict │ 1 │ 36.4ms │ 0 │ 0s │ │ RandomForestClassifier.predict_proba │ 1 │ 1.5ms │ 0 │ 0s │ ├──────────────────────────────────────┼───────────┼──────────┼───────────┼──────────┤ │ Total │ 3 │ 428.2ms │ 0 │ 0s │ └──────────────────────────────────────┴───────────┴──────────┴───────────┴──────────┘
Line Profiler#
The line profiler collects per-line statistics on your script. It can show:
Which lines took the most cumulative time
Which lines (if any) were able to benefit from acceleration
The percentage of each line’s runtime that was spent on GPU through
cuml.accel
⚠️ Warning: The line profiler can add non-negligible overhead. It’s useful for understanding what parts of your code were accelerated, but you shouldn’t compare runtimes when run with the line profiler enabled to other runs.
Example 3: Line Profiling with Ridge Regression#
Let’s use the line profiler to see detailed per-line statistics.
[7]:
%%cuml.accel.line_profile
# Generate data
X, y = make_regression(n_samples=1000, n_features=100, noise=0.1, random_state=42)
# Fit and predict on GPU
ridge = Ridge(alpha=1.0)
ridge.fit(X, y)
predictions = ridge.predict(X)
# Retry, using a hyperparameter that isn't supported on GPU
ridge_cpu = Ridge(positive=True)
ridge_cpu.fit(X, y)
predictions_cpu = ridge_cpu.predict(X)
cuml.accel line profile ┏━━━━┳━━━┳━━━━━━━━━┳━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ ┃ # ┃ N ┃ Time ┃ GPU % ┃ Source ┃ ┡━━━━╇━━━╇━━━━━━━━━╇━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩ │ 1 │ │ │ │ # Generate data │ │ 2 │ 1 │ 3.6ms │ - │ X, y = make_regression(n_samples=1000, n_features=100, noise=0.1, random_state=42) │ │ 3 │ │ │ │ │ │ 4 │ │ │ │ # Fit and predict on GPU │ │ 5 │ 1 │ 948.2µs │ - │ ridge = Ridge(alpha=1.0) │ │ 6 │ 1 │ 9.7ms │ 93.0 │ ridge.fit(X, y) │ │ 7 │ 1 │ 1.8ms │ 98.0 │ predictions = ridge.predict(X) │ │ 8 │ │ │ │ │ │ 9 │ │ │ │ # Retry, using a hyperparameter that isn't supported on GPU │ │ 10 │ 1 │ - │ - │ ridge_cpu = Ridge(positive=True) │ │ 11 │ 1 │ 4.9ms │ 0.0 │ ridge_cpu.fit(X, y) │ │ 12 │ 1 │ 235.8µs │ 0.0 │ predictions_cpu = ridge_cpu.predict(X) │ └────┴───┴─────────┴───────┴────────────────────────────────────────────────────────────────────────────────────┘ Ran in 21.6ms, 50.1% on GPU
The line profiler output shows:
#: Line number
N: Number of times the line was executed
Time: Total time spent on that line
GPU %: Percentage of time spent on GPU for that line
Source: The actual code line
At the bottom, you’ll see the total runtime and the percentage of time spent on GPU.
Example 4: Line Profiling with Multiple Algorithms#
Let’s try a more comprehensive example with multiple machine learning algorithms.
[8]:
from sklearn.linear_model import LogisticRegression
from sklearn.cluster import KMeans
[9]:
%%cuml.accel.line_profile
# Generate data for multiple tasks
X_reg, y_reg = make_regression(n_samples=500, n_features=50, noise=0.1, random_state=42)
X_class, y_class = make_classification(n_samples=500, n_features=20, n_classes=2, random_state=42)
# Regression task
ridge = Ridge(alpha=1.0)
ridge.fit(X_reg, y_reg)
ridge_pred = ridge.predict(X_reg)
# Classification task
logreg = LogisticRegression(random_state=42)
logreg.fit(X_class, y_class)
logreg_pred = logreg.predict(X_class)
# Clustering task
kmeans = KMeans(n_clusters=3, random_state=42)
kmeans.fit(X_class)
kmeans_pred = kmeans.predict(X_class)
cuml.accel line profile ┏━━━━┳━━━┳━━━━━━━━━┳━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ ┃ # ┃ N ┃ Time ┃ GPU % ┃ Source ┃ ┡━━━━╇━━━╇━━━━━━━━━╇━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩ │ 1 │ │ │ │ # Generate data for multiple tasks │ │ 2 │ 1 │ 1.3ms │ - │ X_reg, y_reg = make_regression(n_samples=500, n_features=50, noise=0.1, random_stat… │ │ 3 │ 1 │ 1.2ms │ - │ X_class, y_class = make_classification(n_samples=500, n_features=20, n_classes=2, r… │ │ 4 │ │ │ │ │ │ 5 │ │ │ │ # Regression task │ │ 6 │ 1 │ 849.3µs │ - │ ridge = Ridge(alpha=1.0) │ │ 7 │ 1 │ 5.3ms │ 90.0 │ ridge.fit(X_reg, y_reg) │ │ 8 │ 1 │ 1.2ms │ 93.0 │ ridge_pred = ridge.predict(X_reg) │ │ 9 │ │ │ │ │ │ 10 │ │ │ │ # Classification task │ │ 11 │ 1 │ - │ - │ logreg = LogisticRegression(random_state=42) │ │ 12 │ 1 │ 595.1ms │ 99.0 │ logreg.fit(X_class, y_class) │ │ 13 │ 1 │ 93.9ms │ 99.0 │ logreg_pred = logreg.predict(X_class) │ │ 14 │ │ │ │ │ │ 15 │ │ │ │ # Clustering task │ │ 16 │ 1 │ - │ - │ kmeans = KMeans(n_clusters=3, random_state=42) │ │ 17 │ 1 │ 74.9ms │ 99.0 │ kmeans.fit(X_class) │ │ 18 │ 1 │ 2ms │ 98.0 │ kmeans_pred = kmeans.predict(X_class) │ └────┴───┴─────────┴───────┴──────────────────────────────────────────────────────────────────────────────────────┘ Ran in 775.9ms, 99.3% on GPU
Programmatic Profiling#
You can also use the profilers programmatically with context managers. This is useful when you want to profile specific sections of code rather than entire cells.
[10]:
# Generate data
X, y = make_regression(n_samples=1000, n_features=100, noise=0.1, random_state=42)
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)
[11]:
# Using function profiler programmatically
# Note: that requires to import cuml – typically not needed for zero-code-change acceleration
import cuml
with cuml.accel.profile():
# This section will be profiled
ridge = Ridge(alpha=1.0)
ridge.fit(X_train, y_train)
predictions = ridge.predict(X_test)
# This will fall back to CPU
ridge_cpu = Ridge(positive=True)
ridge_cpu.fit(X_train, y_train)
predictions_cpu = ridge_cpu.predict(X_test)
# This section will NOT be profiled
print("Profiling complete!")
cuml.accel profile ┏━━━━━━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━┓ ┃ Function ┃ GPU calls ┃ GPU time ┃ CPU calls ┃ CPU time ┃ ┡━━━━━━━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━┩ │ Ridge.fit │ 1 │ 9.2ms │ 1 │ 3.8ms │ │ Ridge.predict │ 1 │ 1.1ms │ 1 │ 155µs │ ├───────────────┼───────────┼──────────┼───────────┼──────────┤ │ Total │ 2 │ 10.3ms │ 2 │ 4ms │ └───────────────┴───────────┴──────────┴───────────┴──────────┘ Not all operations ran on the GPU. The following functions required CPU fallback for the following reasons: * Ridge.fit - `positive=True` is not supported * Ridge.predict - Estimator not fit on GPU
Profiling complete!
Logging#
In addition to profiling, cuml.accel also provides logging capabilities. You can enable different levels of logging to see what’s happening behind the scenes.
Setting Log Levels#
You can set the logging level when installing cuml.accel programmatically:
[12]:
# Note: This needs to be done before loading the extension
# Uncomment and restart kernel to try different log levels
# import cuml
# cuml.accel.install(log_level="debug") # Most verbose
# cuml.accel.install(log_level="info") # Shows GPU/CPU dispatch info
# cuml.accel.install(log_level="warn") # Default - warnings only
Example with Info Logging#
Let’s demonstrate what info-level logging looks like. First, let’s reinstall cuml.accel with info logging:
[13]:
# Reinstall with info logging
cuml.accel.install(log_level="info")
[14]:
# Now let's run some code and see the logging output
X, y = make_regression(n_samples=100, n_features=10, noise=0.1, random_state=42)
# This should run on GPU
ridge = Ridge(alpha=1.0)
ridge.fit(X, y)
ridge.predict(X)
# This should fall back to CPU
ridge_cpu = Ridge(positive=True)
ridge_cpu.fit(X, y)
ridge_cpu.predict(X)
[14]:
array([-4.96828185e+02, 4.13259834e+02, 2.29693047e+02, -2.01945381e+02,
-1.82165742e+02, -1.27461725e+02, -1.84216790e+02, 6.41643935e+01,
2.81977988e+01, -9.85732803e+01, -2.48726688e+02, -4.59059179e+01,
-3.62515595e+02, -1.97116640e+02, -7.59989954e+01, -1.46745797e+02,
1.83729766e+02, 1.52333807e+02, 1.58614336e+02, -2.80348072e+02,
1.20902174e+02, -1.17809033e+02, -9.97851311e+01, -1.12611893e+02,
3.63757770e+02, -9.44789347e+01, 3.73068707e+02, -1.63022890e+02,
-1.79148538e+02, -4.76543795e+01, -1.22622512e+02, 2.53736026e+02,
-6.01694025e+01, -1.36405943e+01, 4.60700767e+02, 2.92104314e+00,
-1.23464126e+01, 3.97667623e+01, -5.95730592e+01, 2.53842230e+02,
-6.30289062e+01, 4.94020282e-01, 2.02603324e+01, -1.42016832e+02,
3.67620494e+02, 1.61207400e+02, 1.77934285e+02, -3.49704150e+02,
1.48142903e+01, -9.68361205e+01, 3.95261071e+01, 1.98248208e+02,
1.47737919e+02, -3.57354347e+02, -3.85222830e+01, -5.95684855e+01,
1.27330414e+02, 2.62530067e+02, 7.13475452e+01, 3.69909633e+01,
1.27019908e+02, -2.68814318e+00, 1.64428940e+02, 6.70256697e+01,
2.92337172e+02, 2.49242376e+02, -4.03311726e+02, -3.85953399e+01,
6.14672781e+01, 1.30952366e+02, 2.87280719e+02, -2.58860504e+02,
1.10095893e+01, 7.70383502e+01, -1.57451567e+02, -3.51116613e+02,
1.33489115e+02, 1.39837447e+02, -2.91451101e+02, 7.65135528e+01,
2.36832431e+02, -4.84163633e+01, 1.86140659e+02, 2.10714217e+02,
7.20502477e+01, 1.10458158e+02, 8.35301830e+01, 2.04801832e+02,
1.87477964e+02, 2.18505503e+01, -1.09905765e+02, -1.03149695e+02,
-5.95948543e+01, 1.66125538e+01, -1.59187302e+02, -1.55099546e+02,
-5.64796237e+01, 1.95535745e+02, 5.09002161e+01, 1.57947532e+01])
Key Takeaways#
Function Profiler (
%%cuml.accel.profile): Best for understanding which methods were accelerated and why some fell back to CPULine Profiler (
%%cuml.accel.line_profile): Best for understanding which specific lines of code benefited from acceleration and the overall GPU utilization percentageLogging: Useful for real-time feedback on what’s happening during execution
Performance Insights:
High GPU utilization percentages indicate good acceleration
CPU fallbacks are clearly identified with reasons
Small datasets may show higher GPU times due to transfer overhead
Larger datasets typically show better GPU acceleration benefits
Debugging: Use these tools to identify why certain operations aren’t being accelerated and optimize your code accordingly.
The profiling tools in cuml.accel are essential for understanding and optimizing your GPU-accelerated machine learning workflows!