nnpack is not reproducible

DoneSubmitted by Ludovic Courtès.
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4 participants
  • Kyle Meyer
  • Ludovic Courtès
  • Ludovic Courtès
  • zimoun
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unassigned
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normal
L
L
Ludovic Courtès wrote on 19 Sep 2021 11:57
python-pytorch is not reproducible
(address . bug-guix@gnu.org)
875yuwsxad.fsf@inria.fr
Bad news!

Toggle snippet (20 lines)
$ guix challenge python-pytorch
/gnu/store/dgdswx4vvf07xmhih21n4fnr68dh3fhd-python-pytorch-1.9.0 contents differ:
no local build for '/gnu/store/dgdswx4vvf07xmhih21n4fnr68dh3fhd-python-pytorch-1.9.0'
https://ci.guix.gnu.org/nar/lzip/dgdswx4vvf07xmhih21n4fnr68dh3fhd-python-pytorch-1.9.0: 0i55iwy3z4da4lhn93dnrmz775s9ga5kyfli6cmrchacacf9xfpq
https://bordeaux.guix.gnu.org/nar/lzip/dgdswx4vvf07xmhih21n4fnr68dh3fhd-python-pytorch-1.9.0: 1fl2v4pd0gcw7wp5k662q0zd4lvvzsggcm5ii8b4kq4v6synhkic
differing file:
/lib/python3.8/site-packages/torch/lib/libtorch_cpu.so

1 store items were analyzed:
- 0 (0.0%) were identical
- 1 (100.0%) differed
- 0 (0.0%) were inconclusive
$ guix describe
Generacio 189 Aug 30 2021 12:09:27 (nuna)
guix f91ae94
repository URL: https://git.savannah.gnu.org/git/guix.git
branch: master
commit: f91ae9425bb385b60396a544afe27933896b8fa3

The file is 165┬áMiB and Diffoscope (which reads the output of ‘objdump’)
takes forever on it.

However, by comparing the output of ‘strings’ on each file, we get a
hint:
diff -ubBr --show-c-function /tmp/str2 /tmp/str1
--- /tmp/str2 2021-09-19 11:14:47.806798779 +0200
+++ /tmp/str1 2021-09-19 11:14:41.962761127 +0200
@@ -1100584,472 +1100584,472 @@ compute_fast_convolution_input_gradient
compute_grad_kernel_transform
compute_fast_convolution_kernel_gradient.isra.0
compute_fast_convolution_output
-nnp_fft8x8_with_offset_and_stream__avx2.__local0
-nnp_fft8x8_with_offset_and_stream__avx2.__local13
-nnp_fft8x8_with_offset_and_stream__avx2.__local18
-nnp_fft8x8_with_offset_and_stream__avx2.__local1
+nnp_fft8x8_with_offset_and_stream__avx2.__local5
nnp_fft8x8_with_offset_and_stream__avx2.__local16
+nnp_fft8x8_with_offset_and_stream__avx2.__local6
+nnp_fft8x8_with_offset_and_stream__avx2.__local11
+nnp_fft8x8_with_offset_and_stream__avx2.__local0
nnp_fft8x8_with_offset_and_stream__avx2.__local2
nnp_fft8x8_with_offset_and_stream__avx2.__local7
-nnp_fft8x8_with_offset_and_stream__avx2.__local17
-nnp_fft8x8_with_offset_and_stream__avx2.__local10
-nnp_fft8x8_with_offset_and_stream__avx2.__local8
nnp_fft8x8_with_offset_and_stream__avx2.__local15
+nnp_fft8x8_with_offset_and_stream__avx2.__local8
nnp_fft8x8_with_offset_and_stream__avx2.__local3
-nnp_fft8x8_with_offset_and_stream__avx2.__local6
-nnp_fft8x8_with_offset_and_stream__avx2.__local14
-nnp_fft8x8_with_offset_and_stream__avx2.__local9
+nnp_fft8x8_with_offset_and_stream__avx2.__local1
nnp_fft8x8_with_offset_and_stream__avx2.__local4
[…]
nnp_shdotxf8__avx2.__local13
-nnp_shdotxf8__avx2.__local15
nnp_shdotxf8__avx2.__local0
+nnp_shdotxf8__avx2.__local9
+nnp_shdotxf8__avx2.__local10
+nnp_shdotxf8__avx2.__local11
+nnp_shdotxf8__avx2.__local12
+nnp_shdotxf8__avx2.__local2
This appears to come from NNPACK, one of the libraries that are still
bundled. These functions seem to be generated by Python scripts that
use PeachPy, such as NNPACK/src/x86_64-fma/2d-fourier-8x8.py:

Toggle snippet (8 lines)
for post_operation in ["stream", "store"]:
fft8x8_arguments = (arg_t_pointer, arg_f_pointer, arg_t_stride, arg_f_stride, arg_row_count, arg_column_count, arg_row_offset, arg_column_offset)
with Function("nnp_fft8x8_with_offset_and_{post_operation}__avx2".format(post_operation=post_operation),
fft8x8_arguments, target=uarch.default + isa.fma3 + isa.avx2):
[…]


The ‘__local’ bit in the name comes from PeachPy, in peachpy/name.py:

Toggle snippet (8 lines)
suffixed_name = "__local" + str(suffix)
for name_object in iter(unnamed_objects):
# Generate a non-conflicting name by appending a suffix
while suffixed_name in self.names:
suffix += 1
suffixed_name = "__local" + str(suffix)

So the problem may be that these things get generated in parallel, and
thus numbering is non-deterministic.

NNPACK/CMakeLists.txt has this bit to generate targets to build all
that:

Toggle snippet (10 lines)
ADD_CUSTOM_COMMAND(
OUTPUT ${obj}
COMMAND "PYTHONPATH=${PEACHPY_PYTHONPATH}"
${PYTHON_EXECUTABLE} -m peachpy.x86_64
-mabi=sysv -g4 -mimage-format=${PEACHPY_IMAGE_FORMAT}
"-I${PROJECT_SOURCE_DIR}/src" "-I${PROJECT_SOURCE_DIR}/src/x86_64-fma" "-I${FP16_SOURCE_DIR}/include"
-o ${obj} "${PROJECT_SOURCE_DIR}/${src}"
DEPENDS ${NNPACK_BACKEND_PEACHPY_OBJS})

It might be that building just those targets sequentially would solve
the problem.

To be continued…

Ludo’.
L
L
Ludovic Courtès wrote on 21 Sep 2021 17:17
(address . 50672@debbugs.gnu.org)
87a6k6j6uu.fsf@gnu.org
Ludovic Courtès <ludovic.courtes@inria.fr> skribis:

Toggle quote (19 lines)
> $ guix challenge python-pytorch
> /gnu/store/dgdswx4vvf07xmhih21n4fnr68dh3fhd-python-pytorch-1.9.0 contents differ:
> no local build for '/gnu/store/dgdswx4vvf07xmhih21n4fnr68dh3fhd-python-pytorch-1.9.0'
> https://ci.guix.gnu.org/nar/lzip/dgdswx4vvf07xmhih21n4fnr68dh3fhd-python-pytorch-1.9.0: 0i55iwy3z4da4lhn93dnrmz775s9ga5kyfli6cmrchacacf9xfpq
> https://bordeaux.guix.gnu.org/nar/lzip/dgdswx4vvf07xmhih21n4fnr68dh3fhd-python-pytorch-1.9.0: 1fl2v4pd0gcw7wp5k662q0zd4lvvzsggcm5ii8b4kq4v6synhkic
> differing file:
> /lib/python3.8/site-packages/torch/lib/libtorch_cpu.so
>
> 1 store items were analyzed:
> - 0 (0.0%) were identical
> - 1 (100.0%) differed
> - 0 (0.0%) were inconclusive
> $ guix describe
> Generacio 189 Aug 30 2021 12:09:27 (nuna)
> guix f91ae94
> repository URL: https://git.savannah.gnu.org/git/guix.git
> branch: master
> commit: f91ae9425bb385b60396a544afe27933896b8fa3

L
L
Ludovic Courtès wrote on 24 Sep 2021 16:04
(address . 50672@debbugs.gnu.org)
87tuiam5ni.fsf@gnu.org
Ludovic Courtès <ludovic.courtes@inria.fr> skribis:

Toggle quote (2 lines)
PyTorch upstream noted that the problem is in NNPACK, not PyTorch
proper.

Having unbundled NNPACK in d326dec8115cf5e2cac9497633dc11ecc970361b, I
can confirm that PyTorch itself is now reproducible, but NNPACK isn’t.


Ludo’.
L
L
Ludovic Courtès wrote on 26 Sep 2021 22:27
control message for bug #50672
(address . control@debbugs.gnu.org)
87h7e7krpx.fsf@gnu.org
retitle 50672 nnpack is not reproducible
quit
Z
Z
zimoun wrote on 27 Sep 2021 15:25
Re: bug#50672: python-pytorch is not reproducible
(name . Ludovic Courtès)(address . ludovic.courtes@inria.fr)(address . 50672@debbugs.gnu.org)
CAJ3okZ203LfGLBsymxRTiZpJ2FQrQAFa-di4sZUytyjnz0KTsA@mail.gmail.com
Hi,

On Fri, 24 Sept 2021 at 16:11, Ludovic Courtès <ludovic.courtes@inria.fr> wrote:

Toggle quote (3 lines)
> Having unbundled NNPACK in d326dec8115cf5e2cac9497633dc11ecc970361b, I
> can confirm that PyTorch itself is now reproducible, but NNPACK isn’t.

I reproduce: "guix build nnpack --no-grafts --check" differs. Pytorch, not.

Toggle quote (3 lines)
> PyTorch upstream noted that the problem is in NNPACK, not PyTorch
> proper.

Closing this report?

However, I notice 2 things:

1- Unbundled dependencies are still fetched
2- Does the Git submodule mechanism work with the SWH fallback?

Toggle snippet (57 lines)
Initialized empty Git repository in
/gnu/store/…-python-pytorch-1.9.0-checkout/.git/
From https://github.com/pytorch/pytorch
* tag v1.9.0 -> FETCH_HEAD

[...]

HEAD is now at d69c22d [docs] Add torch.package documentation for beta
release (#59886)
/gnu/store/…-bash-minimal-5.0.16/bin/sh: warning: setlocale: LC_ALL:
cannot change locale (en_US.utf8)
Submodule 'android/libs/fbjni'
(https://github.com/facebookincubator/fbjni.git) registered for path
'android/libs/fbjni'
Submodule 'third_party/NNPACK_deps/FP16'
(https://github.com/Maratyszcza/FP16.git) registered for path
'third_party/FP16'
Submodule 'third_party/NNPACK_deps/FXdiv'
(https://github.com/Maratyszcza/FXdiv.git) registered for path
'third_party/FXdiv'
Submodule 'third_party/NNPACK'
(https://github.com/Maratyszcza/NNPACK.git) registered for path
'third_party/NNPACK'
Submodule 'third_party/QNNPACK' (https://github.com/pytorch/QNNPACK)
registered for path 'third_party/QNNPACK'
Submodule 'third_party/XNNPACK'
(https://github.com/google/XNNPACK.git) registered for path
'third_party/XNNPACK'

[...]

Submodule 'third_party/NNPACK_deps/psimd'
(https://github.com/Maratyszcza/psimd.git) registered for path
'third_party/psimd'
Submodule 'third_party/NNPACK_deps/pthreadpool'
(https://github.com/Maratyszcza/pthreadpool.git) registered for path
'third_party/pthreadpool'

[...]

Cloning into '/gnu/store/…-python-pytorch-1.9.0-checkout/third_party/NNPACK'...
Cloning into '/gnu/store/…-python-pytorch-1.9.0-checkout/third_party/QNNPACK'...
Cloning into '/gnu/store/…-python-pytorch-1.9.0-checkout/third_party/XNNPACK'...

[...]

Submodule path 'third_party/NNPACK': checked out
'c07e3a0400713d546e0dea2d5466dd22ea389c73'
Submodule path 'third_party/QNNPACK': checked out
'7d2a4e9931a82adc3814275b6219a03e24e36b4c'
Submodule path 'third_party/XNNPACK': checked out
'55d53a4e7079d38e90acd75dd9e4f9e781d2da35'

[...]


Cheers,
simon
L
L
Ludovic Courtès wrote on 28 Sep 2021 11:24
(name . zimoun)(address . zimon.toutoune@gmail.com)(address . 50672@debbugs.gnu.org)
87ilylf3yn.fsf@inria.fr
Hi,

zimoun <zimon.toutoune@gmail.com> skribis:

Toggle quote (12 lines)
> On Fri, 24 Sept 2021 at 16:11, Ludovic Courtès <ludovic.courtes@inria.fr> wrote:
>
>> Having unbundled NNPACK in d326dec8115cf5e2cac9497633dc11ecc970361b, I
>> can confirm that PyTorch itself is now reproducible, but NNPACK isn’t.
>
> I reproduce: "guix build nnpack --no-grafts --check" differs. Pytorch, not.
>
>> PyTorch upstream noted that the problem is in NNPACK, not PyTorch
>> proper.
>
> Closing this report?

No, I’ve retitled it. Now looking at PeachPy:


Toggle quote (4 lines)
> However, I notice 2 things:
>
> 1- Unbundled dependencies are still fetched

Yes but the snippet wipes them right after.

Toggle quote (2 lines)
> 2- Does the Git submodule mechanism work with the SWH fallback?

No, not yet; there’s a comment in (guix git-download). Fixing it should
be doable.

Thanks,
Ludo’.
L
L
Ludovic Courtès wrote on 22 Oct 2021 17:31
Re: bug#50672: nnpack is not reproducible
(name . zimoun)(address . zimon.toutoune@gmail.com)(address . 50672@debbugs.gnu.org)
87pmrxt6tf.fsf_-_@gnu.org
Hi,

Ludovic Courtès <ludovic.courtes@inria.fr> skribis:

Toggle quote (4 lines)
> No, I’ve retitled it. Now looking at PeachPy:
>
> https://github.com/Maratyszcza/PeachPy/issues/88

For the record, I tried the attached patch in an attempt to sort things
as discussed in the issue above, but it doesn’t have the intended
effect. There must be other unsorted dictionaries elsewhere.

Suggestions welcome!

Ludo’.
Toggle diff (15 lines)
diff --git a/peachpy/name.py b/peachpy/name.py
index b6a03dc..c069fc2 100644
--- a/peachpy/name.py
+++ b/peachpy/name.py
@@ -95,6 +95,10 @@ class Namespace:
             self.prenames[scope_name.prename].add(scope)
 
     def assign_names(self):
+        # Step 0: sort the dictionary for deterministic output
+        self.prenames = dict(sorted(self.prenames.items(),
+                                    key=lambda item: "" if item[0] == None else item[0]))
+
         # Step 1: assign names to symbols with prenames with no conflicts
         for prename in six.iterkeys(self.prenames):
             if prename is not None:
K
K
Kyle Meyer wrote on 23 Oct 2021 05:32
(name . Ludovic Courtès)(address . ludovic.courtes@inria.fr)
87ee8ch0v1.fsf@kyleam.com
Ludovic Courtès writes:

Toggle quote (4 lines)
> For the record, I tried the attached patch in an attempt to sort things
> as discussed in the issue above, but it doesn’t have the intended
> effect. There must be other unsorted dictionaries elsewhere.

Hmm, I don't think dictionaries are a likely culprit here because
Python's dict implementation preserves the insertion order as of Python
v3.6 (and that behavior is declared as part of the language spec with
v3.7).

Toggle quote (13 lines)
> diff --git a/peachpy/name.py b/peachpy/name.py
> index b6a03dc..c069fc2 100644
> --- a/peachpy/name.py
> +++ b/peachpy/name.py
> @@ -95,6 +95,10 @@ class Namespace:
> self.prenames[scope_name.prename].add(scope)
>
> def assign_names(self):
> + # Step 0: sort the dictionary for deterministic output
> + self.prenames = dict(sorted(self.prenames.items(),
> + key=lambda item: "" if item[0] == None else item[0]))
> +

In cases where the order of the keys isn't specified (i.e. Python 3.5
and below), I think the end result after your change is the same: it
creates a new dictionary for sorted _input_, but things won't
necessarily come out in the same order.

I'm not familiar with PeachPy, but taking a peek at name.py, the sets
used for the values of the prenames dictionary could be the problem.
And if that's the case, one solution would be switching those values
from sets to dictionaries.

With the change below (on top of PeachPy's 257881e), nnpack builds
reliably for me across a couple of attempts:

$ guix-dev build --with-git-url=python-peachpy=$local --no-grafts --check nnpack
successfully built /gnu/store/7z4nl55gssrf9na7wsvmw1dsqgawnj2p-nnpack-0.0-1.c07e3a0.drv
successfully built /gnu/store/7z4nl55gssrf9na7wsvmw1dsqgawnj2p-nnpack-0.0-1.c07e3a0.drv
/gnu/store/4ihjil42fbk53q73gpvdakynbv9q5q09-nnpack-0.0-1.c07e3a0

Toggle diff (20 lines)
diff --git a/peachpy/name.py b/peachpy/name.py
index b6a03dc..412079d 100644
--- a/peachpy/name.py
+++ b/peachpy/name.py
@@ -86,13 +86,13 @@ def add_scoped_name(self, scoped_name):
                 self.names[scope_name.name] = scope
         else:
             assert scope_name.name is None
-            self.prenames.setdefault(scope_name.prename, set())
+            self.prenames.setdefault(scope_name.prename, {})
             if subscoped_name:
                 for subscope in iter(self.prenames[scope_name.prename]):
                     if isinstance(subscope, Namespace) and subscope.scope_name is scope_name:
                         subscope.add_scoped_name(subscoped_name)
                         return
-            self.prenames[scope_name.prename].add(scope)
+            self.prenames[scope_name.prename][scope] = None
 
     def assign_names(self):
         # Step 1: assign names to symbols with prenames with no conflicts
L
L
Ludovic Courtès wrote on 25 Oct 2021 14:54
(name . Kyle Meyer)(address . kyle@kyleam.com)
87a6ixl0xn.fsf@inria.fr
Hi!

Kyle Meyer <kyle@kyleam.com> skribis:

Toggle quote (11 lines)
> Ludovic Courtès writes:
>
>> For the record, I tried the attached patch in an attempt to sort things
>> as discussed in the issue above, but it doesn’t have the intended
>> effect. There must be other unsorted dictionaries elsewhere.
>
> Hmm, I don't think dictionaries are a likely culprit here because
> Python's dict implementation preserves the insertion order as of Python
> v3.6 (and that behavior is declared as part of the language spec with
> v3.7).

Ah, silly me.

Toggle quote (5 lines)
> In cases where the order of the keys isn't specified (i.e. Python 3.5
> and below), I think the end result after your change is the same: it
> creates a new dictionary for sorted _input_, but things won't
> necessarily come out in the same order.

Noted, thanks for explaining.

Toggle quote (13 lines)
> I'm not familiar with PeachPy, but taking a peek at name.py, the sets
> used for the values of the prenames dictionary could be the problem.
> And if that's the case, one solution would be switching those values
> from sets to dictionaries.
>
> With the change below (on top of PeachPy's 257881e), nnpack builds
> reliably for me across a couple of attempts:
>
> $ guix-dev build --with-git-url=python-peachpy=$local --no-grafts --check nnpack
> successfully built /gnu/store/7z4nl55gssrf9na7wsvmw1dsqgawnj2p-nnpack-0.0-1.c07e3a0.drv
> successfully built /gnu/store/7z4nl55gssrf9na7wsvmw1dsqgawnj2p-nnpack-0.0-1.c07e3a0.drv
> /gnu/store/4ihjil42fbk53q73gpvdakynbv9q5q09-nnpack-0.0-1.c07e3a0

Your patch does the trick, indeed. I went ahead and pushed it as
b87fe805aa66851f17f56078cb0e94f7cc4525df.

Thank you!

Ludo’.
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