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| author | Fangrui Song <i@maskray.me> | 2023-10-22 16:50:03 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-10-22 16:50:03 -0700 |
| commit | a24418375a707b7314e7687888dd02eaefca42cd (patch) | |
| tree | 48c4a298b6efb4d4b6fdf56f3918151fea151b2f /lldb/source/Plugins/ScriptInterpreter/Python | |
| parent | 8511ade505588473154906e903302659fd833b48 (diff) | |
| download | llvm-a24418375a707b7314e7687888dd02eaefca42cd.zip llvm-a24418375a707b7314e7687888dd02eaefca42cd.tar.gz llvm-a24418375a707b7314e7687888dd02eaefca42cd.tar.bz2 | |
[CodeLayout] cache-directed sort: limit max chain size (#69039)
When linking an executable with a slightly larger executable,
ld.lld --call-graph-profile-sort=cdsort can be very slow (see #68638).
```
4.6% 20.7Mi .text.hot
3.5% 15.9Mi .text
3.4% 15.2Mi .text.unknown
```
Add cl option `cdsort-max-chain-size`, which is similar to
`ext-tsp-max-chain-size`, and set it to 128, to improve performance.
In `ld.lld @response.txt --threads=4 --call-graph-profile-sort=cdsort
--time-trace"
builds, the "Total Sort sections" time is measured as follows:
* -mllvm -cdsort-max-chain-size=64: 1.321813
* -mllvm -cdsort-max-chain-size=128: 2.030425
* -mllvm -cdsort-max-chain-size=256: 2.927684
* -mllvm -cdsort-max-chain-size=512: 5.493106
* unlimited: 9 minutes
The rest part takes 6.8s.
Diffstat (limited to 'lldb/source/Plugins/ScriptInterpreter/Python')
0 files changed, 0 insertions, 0 deletions