mirror of
https://github.com/bitcoin/bitcoin.git
synced 2025-02-23 12:33:26 -05:00
34 lines
2.1 KiB
Markdown
34 lines
2.1 KiB
Markdown
- Node and Mining
|
|
|
|
---
|
|
|
|
- **PR #31384** fixed an issue where block reserved weight for fixed-size block header, transactions count,
|
|
and coinbase transaction was done in two separate places.
|
|
Before this pull request, the policy default for the maximum block weight was `3,996,000` WU, calculated by
|
|
subtracting `4,000 WU` from the `4,000,000 WU` consensus limit to account for the fixed-size block header,
|
|
transactions count, and coinbase transaction. During block assembly, Bitcoin Core clamped custom `-blockmaxweight`
|
|
value to not be more than the policy default.
|
|
|
|
Additionally, the mining code added another `4,000 WU` to the initial reservation, reducing the effective block template
|
|
size to `3,992,000 WU`.
|
|
|
|
Due to this issue, the total reserved weight was always `8,000 WU`, meaning that even when specifying a `-blockmaxweight`
|
|
higher than the policy default, the actual block size never exceeded `3,992,000 WU`.
|
|
|
|
The fix consolidates the reservation into a single place and introduces a new startup option,
|
|
`-blockreservedweight` (default: `8,000 WU`). This startup option specifies the reserved weight for
|
|
the fixed-size block header, transactions count, and coinbase transaction.
|
|
The default value of `-blockreservedweight` was chosen to preserve the previous behavior.
|
|
|
|
**Upgrade Note:** The default `-blockreservedweight` ensures backward compatibility for users who relied on the previous behavior.
|
|
|
|
Users who manually set `-blockmaxweight` to its maximum value of `4,000,000 WU` should be aware that this
|
|
value previously had no effect since it was clamped to `3,996,000 WU`.
|
|
|
|
Users lowering `-blockreservedweight` should ensure that the total weight (for the block header, transaction count, and coinbase transaction)
|
|
does not exceed the reduced value.
|
|
|
|
As a safety check, Bitcoin core will **fail to start** when `-blockreservedweight` init parameter value is lower than `2000` weight units.
|
|
|
|
Bitcoin Core will also **fail to start** if the `-blockmaxweight` or `-blockreservedweight` init parameter exceeds
|
|
consensus limit of `4,000,000` weight units.
|