Improve strings contains/find performance for smaller strings #17330

davidwendt · 2024-11-14T22:40:26Z

Description

Replaces usage of cudf::string_view::find() with loop and call to cudf::string_view::compare() where possible.
This showed significant performance improvement.
This was also slightly faster than a KMP prototype implementation.
Also updates the find/contains benchmarks to remove the 2GB limit and include column versions of the find APIs.

Checklist

I am familiar with the Contributing Guidelines.
New or existing tests cover these changes.
The documentation is up to date with these changes.

davidwendt · 2024-11-15T16:10:59Z

Benchmarks show significant speed up for shorter strings for scalar contains and find

## [0] NVIDIA RTX 5880 Ada Generation

| width | num_rows | hits |   api    | target |   Ref Time |   Cmp Time |        Diff |   %Diff |
|-------|----------|------|----------|--------|------------|------------|-------------|---------|
|  32   |  32768   |  20  | contains | scalar |  42.512 us |  38.013 us |   -4.499 us | -10.58% |
|  64   |  32768   |  20  | contains | scalar |  71.327 us |  62.462 us |   -8.865 us | -12.43% |
|  128  |  32768   |  20  | contains | scalar |  55.435 us |  53.488 us |   -1.948 us |  -3.51% |
|  256  |  32768   |  20  | contains | scalar |  70.788 us |  68.642 us |   -2.146 us |  -3.03% |
|  32   |  262144  |  20  | contains | scalar |  75.077 us |  49.207 us |  -25.870 us | -34.46% |
|  64   |  262144  |  20  | contains | scalar | 178.340 us |  89.774 us |  -88.566 us | -49.66% |
|  128  |  262144  |  20  | contains | scalar | 249.517 us | 247.330 us |   -2.187 us |  -0.88% |
|  256  |  262144  |  20  | contains | scalar | 358.435 us | 356.482 us |   -1.953 us |  -0.54% |
|  32   | 2097152  |  20  | contains | scalar | 341.067 us | 170.980 us | -170.087 us | -49.87% |
|  64   | 2097152  |  20  | contains | scalar |   1.020 ms | 424.781 us | -595.535 us | -58.37% |
|  128  | 2097152  |  20  | contains | scalar |   1.797 ms |   1.799 ms |    1.739 us |   0.10% |
|  256  | 2097152  |  20  | contains | scalar |   2.648 ms |   2.651 ms |    2.949 us |   0.11% |
|  32   |  32768   |  80  | contains | scalar |  43.069 us |  36.631 us |   -6.438 us | -14.95% |
|  64   |  32768   |  80  | contains | scalar |  74.226 us |  61.119 us |  -13.107 us | -17.66% |
|  128  |  32768   |  80  | contains | scalar |  61.266 us |  57.107 us |   -4.159 us |  -6.79% |
|  256  |  32768   |  80  | contains | scalar |  76.492 us |  72.194 us |   -4.298 us |  -5.62% |
|  32   |  262144  |  80  | contains | scalar |  89.574 us |  53.098 us |  -36.476 us | -40.72% |
|  64   |  262144  |  80  | contains | scalar | 200.841 us |  96.890 us | -103.951 us | -51.76% |
|  128  |  262144  |  80  | contains | scalar | 279.909 us | 278.216 us |   -1.693 us |  -0.60% |
|  256  |  262144  |  80  | contains | scalar | 387.450 us | 386.376 us |   -1.074 us |  -0.28% |
|  32   | 2097152  |  80  | contains | scalar | 459.934 us | 209.319 us | -250.615 us | -54.49% |
|  64   | 2097152  |  80  | contains | scalar |   1.213 ms | 411.948 us | -800.896 us | -66.03% |
|  128  | 2097152  |  80  | contains | scalar |   2.042 ms |   2.045 ms |    2.777 us |   0.14% |
|  256  | 2097152  |  80  | contains | scalar |   2.882 ms |   2.885 ms |    3.259 us |   0.11% |

## [0] NVIDIA RTX 5880 Ada Generation

| width | num_rows | hits |  api  | target |   Ref Time |   Cmp Time |        Diff |   %Diff |
|-------|----------|------|-------|--------|------------|------------|-------------|---------|
|  32   |  32768   |  20  | find  | scalar |  46.198 us |  42.149 us |   -4.049 us |  -8.76% |
|  64   |  32768   |  20  | find  | scalar |  75.200 us |  70.511 us |   -4.690 us |  -6.24% |
|  128  |  32768   |  20  | find  | scalar |  84.968 us |  81.511 us |   -3.457 us |  -4.07% |
|  256  |  32768   |  20  | find  | scalar | 106.626 us | 100.825 us |   -5.801 us |  -5.44% |
|  32   |  262144  |  20  | find  | scalar |  75.483 us |  58.425 us |  -17.058 us | -22.60% |
|  64   |  262144  |  20  | find  | scalar | 179.695 us | 129.064 us |  -50.631 us | -28.18% |
|  128  |  262144  |  20  | find  | scalar | 437.466 us | 432.743 us |   -4.723 us |  -1.08% |
|  256  |  262144  |  20  | find  | scalar | 571.513 us | 568.183 us |   -3.330 us |  -0.58% |
|  32   | 2097152  |  20  | find  | scalar | 346.495 us | 229.112 us | -117.383 us | -33.88% |
|  64   | 2097152  |  20  | find  | scalar |   1.028 ms | 670.638 us | -357.811 us | -34.79% |
|  128  | 2097152  |  20  | find  | scalar |   3.243 ms |   3.242 ms |   -0.485 us |  -0.01% |
|  256  | 2097152  |  20  | find  | scalar |   4.292 ms |   4.289 ms |   -3.001 us |  -0.07% |
|  32   |  32768   |  80  | find  | scalar |  43.012 us |  41.202 us |   -1.810 us |  -4.21% |
|  64   |  32768   |  80  | find  | scalar |  70.353 us |  71.941 us |    1.588 us |   2.26% |
|  128  |  32768   |  80  | find  | scalar |  96.212 us | 100.672 us |    4.460 us |   4.64% |
|  256  |  32768   |  80  | find  | scalar | 117.319 us | 120.849 us |    3.530 us |   3.01% |
|  32   |  262144  |  80  | find  | scalar |  91.934 us |  67.151 us |  -24.783 us | -26.96% |
|  64   |  262144  |  80  | find  | scalar | 204.427 us | 130.435 us |  -73.992 us | -36.19% |
|  128  |  262144  |  80  | find  | scalar | 581.534 us | 577.699 us |   -3.835 us |  -0.66% |
|  256  |  262144  |  80  | find  | scalar | 709.497 us | 703.679 us |   -5.817 us |  -0.82% |
|  32   | 2097152  |  80  | find  | scalar | 464.751 us | 311.426 us | -153.325 us | -32.99% |
|  64   | 2097152  |  80  | find  | scalar |   1.220 ms | 649.425 us | -570.523 us | -46.77% |
|  128  | 2097152  |  80  | find  | scalar |   4.409 ms |   4.405 ms |   -4.608 us |  -0.10% |
|  256  | 2097152  |  80  | find  | scalar |   5.384 ms |   5.382 ms |   -2.057 us |  -0.04% |

davidwendt · 2024-11-15T16:16:20Z

The contains column API also showed significant improvement overall with this change.

## [0] NVIDIA RTX 5880 Ada Generation

| width | num_rows | hits |   api    | target |   Ref Time |   Cmp Time |         Diff |   %Diff |
|-------|----------|------|----------|--------|------------|------------|--------------|---------|
|  32   |  32768   |  20  | contains | column |  43.186 us |  35.144 us |    -8.042 us | -18.62% |
|  64   |  32768   |  20  | contains | column |  75.852 us |  59.826 us |   -16.026 us | -21.13% |
|  128  |  32768   |  20  | contains | column | 163.517 us |  99.894 us |   -63.624 us | -38.91% |
|  256  |  32768   |  20  | contains | column | 302.529 us | 171.011 us |  -131.518 us | -43.47% |
|  32   |  262144  |  20  | contains | column |  76.081 us |  50.128 us |   -25.953 us | -34.11% |
|  64   |  262144  |  20  | contains | column | 182.916 us |  93.221 us |   -89.695 us | -49.04% |
|  128  |  262144  |  20  | contains | column | 595.423 us | 239.143 us |  -356.280 us | -59.84% |
|  256  |  262144  |  20  | contains | column |   1.173 ms | 456.718 us |  -716.329 us | -61.07% |
|  32   | 2097152  |  20  | contains | column | 386.547 us | 206.650 us |  -179.897 us | -46.54% |
|  64   | 2097152  |  20  | contains | column |   1.098 ms | 482.762 us |  -614.947 us | -56.02% |
|  128  | 2097152  |  20  | contains | column |   4.085 ms |   1.573 ms | -2512.355 us | -61.49% |
|  256  | 2097152  |  20  | contains | column |   8.244 ms |   3.110 ms | -5133.808 us | -62.28% |
|  32   |  32768   |  80  | contains | column |  42.589 us |  33.726 us |    -8.864 us | -20.81% |
|  64   |  32768   |  80  | contains | column |  73.789 us |  58.302 us |   -15.487 us | -20.99% |
|  128  |  32768   |  80  | contains | column | 164.130 us |  97.675 us |   -66.455 us | -40.49% |
|  256  |  32768   |  80  | contains | column | 307.640 us | 165.999 us |  -141.642 us | -46.04% |
|  32   |  262144  |  80  | contains | column |  90.312 us |  53.633 us |   -36.679 us | -40.61% |
|  64   |  262144  |  80  | contains | column | 204.043 us |  96.802 us |  -107.240 us | -52.56% |
|  128  |  262144  |  80  | contains | column | 559.216 us | 187.786 us |  -371.430 us | -66.42% |
|  256  |  262144  |  80  | contains | column | 978.985 us | 265.986 us |  -712.999 us | -72.83% |
|  32   | 2097152  |  80  | contains | column | 498.635 us | 243.698 us |  -254.938 us | -51.13% |
|  64   | 2097152  |  80  | contains | column |   1.261 ms | 451.149 us |  -810.320 us | -64.24% |
|  128  | 2097152  |  80  | contains | column |   3.957 ms |   1.334 ms | -2622.974 us | -66.28% |
|  256  | 2097152  |  80  | contains | column |   7.262 ms |   2.103 ms | -5158.243 us | -71.03% |

The find column API showed only significant improvement with shorter strings

## [0] NVIDIA RTX 5880 Ada Generation

| width | num_rows | hits |  api  | target |   Ref Time |   Cmp Time |        Diff |   %Diff |
|-------|----------|------|-------|--------|------------|------------|-------------|---------|
|  32   |  32768   |  20  | find  | column |  47.391 us |  42.670 us |   -4.721 us |  -9.96% |
|  64   |  32768   |  20  | find  | column |  96.955 us |  88.535 us |   -8.420 us |  -8.68% |
|  128  |  32768   |  20  | find  | column | 105.372 us | 102.967 us |   -2.405 us |  -2.28% |
|  256  |  32768   |  20  | find  | column | 126.030 us | 122.494 us |   -3.537 us |  -2.81% |
|  32   |  262144  |  20  | find  | column |  76.075 us |  62.058 us |  -14.017 us | -18.43% |
|  64   |  262144  |  20  | find  | column | 202.727 us | 150.489 us |  -52.238 us | -25.77% |
|  128  |  262144  |  20  | find  | column | 482.592 us | 481.785 us |   -0.807 us |  -0.17% |
|  256  |  262144  |  20  | find  | column | 624.475 us | 624.277 us |   -0.198 us |  -0.03% |
|  32   | 2097152  |  20  | find  | column | 367.564 us | 251.290 us | -116.274 us | -31.63% |
|  64   | 2097152  |  20  | find  | column |   1.103 ms | 751.289 us | -351.859 us | -31.90% |
|  128  | 2097152  |  20  | find  | column |   3.498 ms |   3.507 ms |    9.486 us |   0.27% |
|  256  | 2097152  |  20  | find  | column |   4.600 ms |   4.604 ms |    3.822 us |   0.08% |
|  32   |  32768   |  80  | find  | column |  46.525 us |  41.206 us |   -5.319 us | -11.43% |
|  64   |  32768   |  80  | find  | column |  95.081 us |  83.233 us |  -11.848 us | -12.46% |
|  128  |  32768   |  80  | find  | column | 120.962 us | 121.114 us |    0.151 us |   0.13% |
|  256  |  32768   |  80  | find  | column | 141.690 us | 141.546 us |   -0.144 us |  -0.10% |
|  32   |  262144  |  80  | find  | column |  92.277 us |  72.436 us |  -19.841 us | -21.50% |
|  64   |  262144  |  80  | find  | column | 223.713 us | 151.144 us |  -72.568 us | -32.44% |
|  128  |  262144  |  80  | find  | column | 627.288 us | 629.337 us |    2.049 us |   0.33% |
|  256  |  262144  |  80  | find  | column | 761.668 us | 764.135 us |    2.468 us |   0.32% |
|  32   | 2097152  |  80  | find  | column | 485.524 us | 335.784 us | -149.740 us | -30.84% |
|  64   | 2097152  |  80  | find  | column |   1.265 ms | 708.428 us | -556.300 us | -43.99% |
|  128  | 2097152  |  80  | find  | column |   4.683 ms |   4.695 ms |   11.324 us |   0.24% |
|  256  | 2097152  |  80  | find  | column |   5.714 ms |   5.724 ms |    9.203 us |   0.16% |

…ntains

cpp/include/cudf/strings/string_view.cuh

bdice

Two suggestions, otherwise LGTM.

cpp/src/strings/search/find.cu

davidwendt · 2024-12-06T13:32:36Z

/merge

Use a KMP search algorithm for strings contains()

3e15aac

davidwendt added 2 - In Progress Currently a work in progress libcudf Affects libcudf (C++/CUDA) code. strings strings issues (C++ and Python) improvement Improvement / enhancement to an existing function non-breaking Non-breaking change labels Nov 14, 2024

davidwendt self-assigned this Nov 14, 2024

davidwendt added 4 commits November 15, 2024 08:50

Merge branch 'branch-24.12' into kmp-contains

453fdb3

add stream to kernel launch

b7d88f7

replace kmp with compare()

cf8f782

Merge branch 'branch-24.12' into kmp-contains

1d3c292

davidwendt changed the title ~~Use a KMP search algorithm for strings contains()~~ Improve strings contains/find performance for smaller strings Nov 15, 2024

remove commented out code line

4b83025

davidwendt added 6 commits November 18, 2024 10:40

Merge branch 'branch-24.12' into kmp-contains

0d12680

Merge branch 'branch-24.12' into kmp-contains

1ae61d2

Merge branch 'branch-24.12' into kmp-contains

884633d

Merge branch 'branch-24.12' into kmp-contains

e50e37a

Merge branch 'branch-24.12' into kmp-contains

c62f99f

Merge branch 'branch-25.02' into kmp-contains

0b27a4d

davidwendt changed the base branch from branch-24.12 to branch-25.02 November 21, 2024 16:11

davidwendt added 8 commits November 21, 2024 19:48

Merge branch 'kmp-contains' of github.com:davidwendt/cudf into kmp-co…

076fc06

…ntains

Merge branch 'branch-25.02' into kmp-contains

ca5c5e2

move fast-path to string_view::find()

d77b2a4

Merge branch 'branch-25.02' into kmp-contains

83285ec

refactor to improve rfind as well

71811e6

Merge branch 'branch-25.02' into kmp-contains

03aae8c

Merge branch 'branch-25.02' into kmp-contains

6dbb2f4

Merge branch 'branch-25.02' into kmp-contains

287f1f5

davidwendt added 3 commits November 26, 2024 10:18

fix merge conflict

6716389

Merge branch 'kmp-contains' of github.com:davidwendt/cudf into kmp-co…

e9afaa4

…ntains

Merge branch 'branch-25.02' into kmp-contains

770463a

davidwendt added 3 - Ready for Review Ready for review by team and removed 2 - In Progress Currently a work in progress labels Dec 3, 2024

davidwendt marked this pull request as ready for review December 3, 2024 16:49

davidwendt requested a review from a team as a code owner December 3, 2024 16:49

davidwendt requested review from shrshi and nvdbaranec December 3, 2024 16:49

lamarrr reviewed Dec 4, 2024

View reviewed changes

cpp/include/cudf/strings/string_view.cuh Show resolved Hide resolved

cpp/include/cudf/strings/string_view.cuh Show resolved Hide resolved

cpp/include/cudf/strings/string_view.cuh Show resolved Hide resolved

lamarrr self-requested a review December 4, 2024 18:32

lamarrr approved these changes Dec 4, 2024

View reviewed changes

Merge branch 'branch-25.02' into kmp-contains

45e428b

bdice approved these changes Dec 5, 2024

View reviewed changes

cpp/src/strings/search/find.cu Outdated Show resolved Hide resolved

cpp/src/strings/search/find.cu Outdated Show resolved Hide resolved

davidwendt added 2 commits December 5, 2024 14:11

Merge branch 'branch-25.02' into kmp-contains

2a55490

refactor detail::contains lambdas

1cdaf31

rapids-bot bot merged commit 38261f8 into rapidsai:branch-25.02 Dec 6, 2024
104 of 105 checks passed

davidwendt deleted the kmp-contains branch December 6, 2024 13:32

davidwendt mentioned this pull request Dec 13, 2024

[FEA] Improved performance for strings finder_warp_parallel_fn / contains_warp_parallel_fn kernels #15405

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Improve strings contains/find performance for smaller strings #17330

Improve strings contains/find performance for smaller strings #17330

davidwendt commented Nov 14, 2024 •

edited

Loading

davidwendt commented Nov 15, 2024

davidwendt commented Nov 15, 2024

bdice left a comment

davidwendt commented Dec 6, 2024

Improve strings contains/find performance for smaller strings #17330

Improve strings contains/find performance for smaller strings #17330

Conversation

davidwendt commented Nov 14, 2024 • edited Loading

Description

Checklist

davidwendt commented Nov 15, 2024

davidwendt commented Nov 15, 2024

bdice left a comment

Choose a reason for hiding this comment

davidwendt commented Dec 6, 2024

davidwendt commented Nov 14, 2024 •

edited

Loading