-
Notifications
You must be signed in to change notification settings - Fork 515
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Implement cache miss emulation in UVM_CACHING (#1637)
Summary: Pull Request resolved: #1637 Enforce cache misses (even if trace-driven testing doesn't experience cache miss due to limited trace size) so that we can evaluate performance under cache misses. Note that it's not exactly cache misses; enforce access to UVM by overriding lxu_cache_locations -- N / 256 requests. Reviewed By: YuzeDaiMeta Differential Revision: D42194019 fbshipit-source-id: 7e70beddcd530b46c975feba795803411ce70c64
- Loading branch information
1 parent
da01a59
commit 1d8b199
Showing
4 changed files
with
258 additions
and
24 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,119 @@ | ||
| /* | ||
| * Copyright (c) Meta Platforms, Inc. and affiliates. | ||
| * All rights reserved. | ||
| * This source code is licensed under the BSD-style license found in the | ||
| * LICENSE file in the root directory of this source tree. | ||
| */ | ||
| #include <gtest/gtest.h> | ||
|
|
||
| #include "fbgemm_gpu/split_embeddings_cache_cuda.cuh" | ||
|
|
||
| using namespace ::testing; | ||
|
|
||
| // Helper function that generates input tensor for emulate_cache_miss testing. | ||
| at::Tensor generate_lxu_cache_locations( | ||
| const int64_t num_requests, | ||
| const int64_t num_sets, | ||
| const int64_t associativity = 32) { | ||
| const auto lxu_cache_locations = at::randint( | ||
| 0, | ||
| num_sets * associativity, | ||
| {num_requests}, | ||
| at::device(at::kCPU).dtype(at::kInt)); | ||
| return lxu_cache_locations; | ||
| } | ||
|
|
||
| // Wrapper function that takes lxu_cache_locations on CPU, copies it to GPU, | ||
| // runs emulate_cache_miss(), and then returns the result, placed on CPU. | ||
| std::pair<at::Tensor, at::Tensor> run_emulate_cache_miss( | ||
| at::Tensor lxu_cache_locations, | ||
| const int64_t enforced_misses_per_256, | ||
| const bool gather_uvm_stats = false) { | ||
| at::Tensor lxu_cache_locations_copy = at::_to_copy(lxu_cache_locations); | ||
| const auto options = | ||
| lxu_cache_locations.options().device(at::kCUDA).dtype(at::kInt); | ||
| const auto uvm_cache_stats = | ||
| gather_uvm_stats ? at::zeros({6}, options) : at::empty({0}, options); | ||
|
|
||
| const auto lxu_cache_location_with_cache_misses = emulate_cache_miss( | ||
| lxu_cache_locations_copy.to(at::kCUDA), | ||
| enforced_misses_per_256, | ||
| gather_uvm_stats, | ||
| uvm_cache_stats); | ||
| return {lxu_cache_location_with_cache_misses.cpu(), uvm_cache_stats.cpu()}; | ||
| } | ||
|
|
||
| TEST(uvm_cache_miss_emulate_test, no_cache_miss) { | ||
| constexpr int64_t num_requests = 10000; | ||
| constexpr int64_t num_sets = 32768; | ||
| constexpr int64_t associativity = 32; | ||
|
|
||
| auto lxu_cache_locations_cpu = | ||
| generate_lxu_cache_locations(num_requests, num_sets, associativity); | ||
| auto lxu_cache_location_with_cache_misses_and_uvm_cache_stats = | ||
| run_emulate_cache_miss(lxu_cache_locations_cpu, 0); | ||
| auto lxu_cache_location_with_cache_misses = | ||
| lxu_cache_location_with_cache_misses_and_uvm_cache_stats.first; | ||
| EXPECT_TRUE( | ||
| at::equal(lxu_cache_locations_cpu, lxu_cache_location_with_cache_misses)); | ||
| } | ||
|
|
||
| TEST(uvm_cache_miss_emulate_test, enforced_cache_miss) { | ||
| constexpr int64_t num_requests = 10000; | ||
| constexpr int64_t num_sets = 32768; | ||
| constexpr int64_t associativity = 32; | ||
| constexpr std::array<int64_t, 6> enforced_misses_per_256_for_testing = { | ||
| 1, 5, 7, 33, 100, 256}; | ||
|
|
||
| for (const bool miss_in_lxu_cache_locations : {false, true}) { | ||
| for (const bool gather_cache_stats : {false, true}) { | ||
| for (const auto enforced_misses_per_256 : | ||
| enforced_misses_per_256_for_testing) { | ||
| auto lxu_cache_locations_cpu = | ||
| generate_lxu_cache_locations(num_requests, num_sets, associativity); | ||
| if (miss_in_lxu_cache_locations) { | ||
| // one miss in the original lxu_cache_locations; shouldn't be counted | ||
| // as enforced misses from emulate_cache_miss(). | ||
| auto z = lxu_cache_locations_cpu.data_ptr<int32_t>(); | ||
| z[0] = -1; | ||
| } | ||
| auto lxu_cache_location_with_cache_misses_and_uvm_cache_stats = | ||
| run_emulate_cache_miss( | ||
| lxu_cache_locations_cpu, | ||
| enforced_misses_per_256, | ||
| gather_cache_stats); | ||
| auto lxu_cache_location_with_cache_misses = | ||
| lxu_cache_location_with_cache_misses_and_uvm_cache_stats.first; | ||
| EXPECT_FALSE(at::equal( | ||
| lxu_cache_locations_cpu, lxu_cache_location_with_cache_misses)); | ||
|
|
||
| auto x = lxu_cache_locations_cpu.data_ptr<int32_t>(); | ||
| auto y = lxu_cache_location_with_cache_misses.data_ptr<int32_t>(); | ||
| int64_t enforced_misses = 0; | ||
| for (int32_t i = 0; i < lxu_cache_locations_cpu.numel(); ++i) { | ||
| if (x[i] != y[i]) { | ||
| EXPECT_EQ(y[i], -1); | ||
| enforced_misses++; | ||
| } | ||
| } | ||
| int64_t num_requests_over_256 = | ||
| static_cast<int64_t>(num_requests / 256); | ||
| int64_t expected_misses = num_requests_over_256 * | ||
| enforced_misses_per_256 + | ||
| std::min((num_requests - num_requests_over_256 * 256), | ||
| enforced_misses_per_256); | ||
| if (miss_in_lxu_cache_locations) { | ||
| expected_misses--; | ||
| } | ||
| EXPECT_EQ(expected_misses, enforced_misses); | ||
| if (gather_cache_stats) { | ||
| auto uvm_cache_stats = | ||
| lxu_cache_location_with_cache_misses_and_uvm_cache_stats.second; | ||
| auto cache_stats_ptr = uvm_cache_stats.data_ptr<int32_t>(); | ||
| // enforced misses are recorded as conflict misses. | ||
| EXPECT_EQ(expected_misses, cache_stats_ptr[5]); | ||
| } | ||
| } | ||
| } | ||
| } | ||
| } |