Working with fullgraph=False
#
Created On: Jul 28, 2025 | Last Updated On: Jul 29, 2025
While fullgraph=False
is the default torch.compile
setting, the semantics of resuming compilation upon encountering a graph break are more complicated.
You can find details on the fullgraph=False
semantics in the subsections.
The strategy for using torch.compile(fullgraph=False)
is as follows:
Determine the ideal location to place
torch.compile
. Normally, it is the highest-level function that doesn’t result in excessive graph breaks. Functions that do a lot of preprocessing or I/O operations are examples of functions that result in many graph breaks and do not significantly benefit fromtorch.compile
. a. You can isolate issues by first compiling individual functions/modules before compiling entire models.Apply
torch.compiler.disable
to functions in the compiled region that result in a lot of graph breaks and do not benefit from compilation. In this case, one graph break is better than potentially tens or hundreds.Use
TORCH_LOGS="graph_breaks"
or tlparse to investigate remaining graph breaks. Work around these graph breaks using the same approaches as working around graph breaks under thefullgraph=True
programming model. Not all graph breaks need to be removed - some may impact performance more than others. The general rule is to focus on graph breaks that are happening during model computation. a. We recommend usingtorch.compile(backend='eager')
when debugging graph breaks, for faster debugging iteration times