Add doc on gas balancing #6392
Add doc on gas balancing #6392
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Signed-off-by: Jakub Sztandera <[email protected]>
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Thanks for writing this up. I think we should get @ZenGround0's review before merging.
| ## Gas Balancing | ||
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| The gas balancing process targets to set gas costs of syscalls to be in line with | ||
| 10 gas per nanosecond on reference hardware. |
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nit: can we link to the reference hardware section?
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| #### Reference hardware | ||
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| The reference hardware is TR3970x with 128GB of RAM. This is what was available at the time and |
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What do we mean by "the time"? Can we give a date (e.g., 202007 on the rampup to mainnet launch ← this is just me making something up)
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both at the physical time (~06-2020) and what we had in our hands
| Before building `lotus-bench` make sure `EnableGasTracing` in `chain/vm/runtime.go` is set to `true`. | ||
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| The process can be started using `./lotus-bench import` with `--car` flag set to the location of | ||
| CAR chain export. `--start-epoch` and `--end-epoch` can be used to to limit the range of epochs to run |
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Will users know where to get a CAR chain export?
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I'm assuming it will be a developer reading these docs, so I assume they will know.
| The output will be a `bench.json` file containing information about every syscall invoked | ||
| and the time taken by these invocations. This file can grow to be quite big in size so make sure you have |
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Idea: maybe include a couple of sample lines below for reference/
| In these cases the recommended way to estimate gas for given syscall is to perform an `in-vivo` benchmark. | ||
| In the past `in-vitro` as in standalone benchmarks were found to be highly inaccurate when compared to results |
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I see in-vivo and in-vitro. Which is it? Also potentially adjust below
| The best place to hook-in such benchmark is message execution loop in | ||
| `chain/stmgr/stmgr.go` in `ApplyBlocks()`. Depending of time required to complete the syscall it might be |
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Is there a sample PR can point to that has this?
Resolves #6186
I'll keep adding into there.