Wasmtime GitHub notifications bot (Jun 09 2023 at 16:35): Wasmtime GitHub notifications bot (Jun 09 2023 at 16:35):TimonPost opened issue #6548:
There has been a performance regression for module compilation. The PR #5382 added the
trace-logfeature by default (this line)Historically high-frequent trace logs have been a performance bottleneck. Some efforts were made to revert that (#4481, #4484, #2758). In #4484 @bnjbvr added this feature flag, claiming perf increment of 32%, whereafter this flag was enabled by default in #5382.
The following numbers are from sampling the app once before and after with the macos instruments profiler.
The module compilation code takes in total 29.5 sec, of that three log functions here take up ~13 secs in total (43% of total).
Disabling trace logs results in total 10.3s, which is roughly ~65% faster.
<img width="1332" alt="image" src="https://github.com/bytecodealliance/wasmtime/assets/19969910/4636be43-e9c7-4013-84a8-242f9f17ab22">
Feature
We probably want to disable 'trace-log' by default as shown this takes ~60% of the total module compilation. Also we likely want to expose upstream control over this feature.
Benefit
Speeds up compilation by 60% :).
Implementation
- Remove the
trace-logfeature from the default features array incodegen.- Add
trace-logfeature to various crates that depend oncodegen, and from those crates expose the ability to 'enable' trace logs as opt in.- Also expose this feature for
wasmtimecrate so that we can decide on enabling/disabling logs.Details
- Macos 13.0.1, Apple M1 Max
- Precompiled Wasm module is roughly 400MB
Wasmtime GitHub notifications bot (Jun 09 2023 at 16:39):TimonPost edited issue #6548:
There has been a performance regression for module compilation. The PR #5382 added the
trace-logfeature by default (this line)Historically high-frequent trace logs have been a performance bottleneck. Some efforts were made to revert that (#4481, #4484, #2758). In #4484 @bnjbvr added this feature flag, claiming perf increment of 32%, whereafter this flag was enabled by default in #5382.
The following numbers are from sampling the app once before and after with the macos instruments profiler.
The module compilation code takes in total 29.5 sec, of that three log functions here take up ~13 secs in total (43% of total).
Disabling trace logs results in total 10.3s, which is roughly ~65% faster.
<img width="1332" alt="image" src="https://github.com/bytecodealliance/wasmtime/assets/19969910/4636be43-e9c7-4013-84a8-242f9f17ab22">
Branch for this instrumentation can be found here: https://github.com/bytecodealliance/wasmtime/compare/main...TimonPost:wasmtime:timon/make-trace-logs-not-default?expand=1
Feature
We probably want to disable 'trace-log' by default as shown this takes ~60% of the total module compilation. Also we likely want to expose upstream control over this feature.
Benefit
Speeds up compilation by 60% :).
Implementation
- Remove the
trace-logfeature from the default features array incodegen.- Add
trace-logfeature to various crates that depend oncodegen, and from those crates expose the ability to 'enable' trace logs as opt in.- Also expose this feature for
wasmtimecrate so that we can decide on enabling/disabling logs.Details
- Macos 13.0.1, Apple M1 Max
- Precompiled Wasm module is roughly 400MB
Wasmtime GitHub notifications bot (Jun 09 2023 at 17:00):jameysharp commented on issue #6548:
I think this was just an accident, so I've opened #6549 as the minimal fix. It would be nice to also add trace-log features to other crates which enable the feature in cranelift-codegen, but I don't think it's immediately necessary.
Wasmtime GitHub notifications bot (Jun 09 2023 at 17:30):repi commented on issue #6548:
Thanks that minimal fix improves compilation speed for our big model on my machine from 7.0 s -> 5.55s :tada: which is very significant and about what we saw last time when we implemented the feature flag for excluding the heavy trace log statements.
Wasmtime GitHub notifications bot (Jun 09 2023 at 18:28):jameysharp closed issue #6548:
There has been a performance regression for module compilation. The PR #5382 added the
trace-logfeature by default (this line)Historically high-frequent trace logs have been a performance bottleneck. Some efforts were made to revert that (#4481, #4484, #2758). In #4484 @bnjbvr added this feature flag, claiming perf increment of 32%, whereafter this flag was enabled by default in #5382.
The following numbers are from sampling the app once before and after with the macos instruments profiler.
The module compilation code takes in total 29.5 sec, of that three log functions here take up ~13 secs in total (43% of total).
Disabling trace logs results in total 10.3s, which is roughly ~65% faster.
<img width="1332" alt="image" src="https://github.com/bytecodealliance/wasmtime/assets/19969910/4636be43-e9c7-4013-84a8-242f9f17ab22">
Branch for this instrumentation can be found here: https://github.com/bytecodealliance/wasmtime/compare/main...TimonPost:wasmtime:timon/make-trace-logs-not-default?expand=1
Feature
We probably want to disable 'trace-log' by default as shown this takes ~60% of the total module compilation. Also we likely want to expose upstream control over this feature.
Benefit
Speeds up compilation by 60% :).
Implementation
- Remove the
trace-logfeature from the default features array incodegen.- Add
trace-logfeature to various crates that depend oncodegen, and from those crates expose the ability to 'enable' trace logs as opt in.- Also expose this feature for
wasmtimecrate so that we can decide on enabling/disabling logs.Details
- Macos 13.0.1, Apple M1 Max
- Precompiled Wasm module is roughly 400MB
Last updated: Dec 23 2024 at 13:07 UTC