Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30894
This PR begins the process of removing BUILD_NAMEDTENSOR macros. There
will be followups.
Reasons for removing the macros:
- BUILD_NAMEDTENSOR is always on and has been on since pytorch 1.3.0.
- Since we don't test building without it, it is useless to keep around.
- Code becomes nicer to read without the macros
Reasons for not removing the macros:
- potential for feature flagging
Now, I argue against needing to feature flag. The main reason why we
might want to feature flag is if we need to disable the feature.
We'd need a fast switch to disable the feature if someone discovers
in the future that named tensors caused some regression in some existing workflows.
In https://github.com/pytorch/pytorch/pull/25798, I did a variety of
macro- and micro- benchmarks to determine the performance impact of named
tensors on regular tensors.
[The
microbenchmarks](https://github.com/pytorch/pytorch/pull/25798#issuecomment-529014810)
were not very stable, and running the
microbenchmarks for more iterations doesn't actually help because the
noise is not distributed in a nice way. Instead of microbenchmarks I ran
a [profiler
(perf)](https://github.com/pytorch/pytorch/pull/25798#issuecomment-555707645)
to estimate how much overhead named tensors add to unnamed code. I
estimated the overhead to be less than 100ns for `add` and even smaller
for `mm`; there are ways to optimize even futher if we find this to be a
problem.
[Initial
macrobenchmarks](https://github.com/pytorch/pytorch/pull/25798#issuecomment-530539104)
were also not very stable. I ran imagenet for some number of epochs. To
make them more stable, I got rid of the data loading (which seemed to
vary between runs). [In some benchmarkers without data
loading](https://github.com/pytorch/pytorch/pull/25798#issuecomment-562214053),
we can see that the results are less noisy now. These results support
no noticeable regressions in speed.
Test Plan: - wait for CI
Differential Revision: D18858543
Pulled By: zou3519
fbshipit-source-id: 08bf3853a9f506c6b084808dc9ddd1e835f48c13
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26060
This PR enables BUILD_NAMEDTENSOR by default. This is done via including
a header, `c10/core/EnableNamedTensor`, that sets `BUILD_NAMEDTENSOR`.
In the future, the plan is to get rid of the flag entirely: we can
incrementally delete usages after this PR goes in.
This PR also maintains the namedtensor ci vs regular ci distinction.
`test/test_namedtensor.py` only runs if TEST_NAMEDTENSOR=1 is specified.
TEST_NAMEDTENSOR=1 is set on the namedtensor ci. I'll remove this
distinction later and send out an announcement about it; devs will be
responsible for named tensor failures after that.
The initial reason why we had the BUILD_NAMEDTENSOR flag was so that we
could quickly prototype named tensor features without worrying about
adding overhead to the framework. The overheads can be categorized as
memory overhead and performance overhead.
Memory overhead: named tensors adds 1 additional word per Tensor. This
is because TensorImpl stores a `unique_ptr<NamedTensorMetaInterface>`
field. This is not a lot of overhead.
Performance overhead: At all entry points to name inference, we check
if inputs to an op are named. If inputs are not named, we short-circuit
and don't do name inference. These calls should therefore be as
efficient as error-checking code and not take up a lot of time.
My plan is to benchmark a few functions and then post the results in a
comment to this PR.
Test Plan: - [namedtensor ci]
Differential Revision: D17331635
Pulled By: zou3519
fbshipit-source-id: deed901347448ae2c26066c1fa432e3dc0cadb92
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25721
Context: I am starting to work on removing the BUILD_NAMEDTENSOR flag.
Here is the approach:
- Move the macro out of header areas
- Include a new `enable_namedtensor.h` header that does a `#ifndef
BUILD_NAMEDTENSOR #define BUILD_NAMEDTENSOR`.
- Include `enable_namedtensor.h` where necessary. This only really needs
to happen in two files (c10/TensorImpl.h, ATen/Dimname.h).
- Incrementally delete usages of the BUILD_NAMEDTENSOR macro later.
The alternative is to straight up delete all instances of
BUILD_NAMEDTENSOR. This alternative could be disruptive, lead to merge
conflicts, and isn't incremental.
Along with the above, some work needs to be done on feature flagging
named tensors, and merging the namedtensor CI with the regular CI, and
communicating with devs. This work will too be done incrementally.
Test Plan
- [namedtensor ci]
Test Plan: Imported from OSS
Differential Revision: D17210913
Pulled By: zou3519
fbshipit-source-id: c73f128b976bb90212639e8f2a3ad2a6a52b8e0c
Summary:
Currently the build system accepts USE_NAMEDTENSOR from the environment
variable and turns it into NAMEDTENSOR_ENABLED when passing to CMake.
This discrepancy does not seem necessary and complicates the build
system. The naming of this build option is also semantically incorrect
("BUILD_" vis-a-vis "USE_"). This commit eradicate this issue before it
is made into a stable release.
The support of NO_NAMEDTENSOR is also removed, since PyTorch has been
quite inconsistent about "NO_*" build options.
---
Note: All environment variables with their names starting with `BUILD_` are currently automatically passed to CMake with no need of an additional wrapper.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22360
Differential Revision: D16074509
Pulled By: zou3519
fbshipit-source-id: dc316287e26192118f3c99b945454bc50535b2ae
