Maximized block gas limit steps for miners with strong opinions.

geth.core.block_validator.go-block-gaslimit-max-step.diff

diff --git a/core/block_validator.go b/core/block_validator.go
index 37bea2b246..862ee952cc 100644
--- a/core/block_validator.go
+++ b/core/block_validator.go
@@ -107,34 +107,19 @@ func (v *BlockValidator) ValidateState(block *types.Block, statedb *state.StateD
 // ceil if the blocks are full. If the ceil is exceeded, it will always decrease
 // the gas allowance.
 func CalcGasLimit(parent *types.Block, gasFloor, gasCeil uint64) uint64 {
-	// contrib = (parentGasUsed * 3 / 2) / 1024
-	contrib := (parent.GasUsed() + parent.GasUsed()/2) / vars.GasLimitBoundDivisor
 
 	// decay = parentGasLimit / 1024 -1
-	decay := parent.GasLimit()/vars.GasLimitBoundDivisor - 1
+	ethashMaxDelta := parent.GasLimit()/vars.GasLimitBoundDivisor - 1
 
-	/*
-		strategy: gasLimit of block-to-mine is set based on parent's
-		gasUsed value.  if parentGasUsed > parentGasLimit * (2/3) then we
-		increase it, otherwise lower it (or leave it unchanged if it's right
-		at that usage) the amount increased/decreased depends on how far away
-		from parentGasLimit * (2/3) parentGasUsed is.
-	*/
-	limit := parent.GasLimit() - decay + contrib
-	if limit < vars.MinGasLimit {
-		limit = vars.MinGasLimit
+	next := parent.GasLimit()
+	if parent.GasLimit() < gasFloor {
+		next = parent.GasLimit() + ethashMaxDelta
+	} else if parent.GasLimit() > gasCeil {
+		next = parent.GasLimit() - ethashMaxDelta
 	}
-	// If we're outside our allowed gas range, we try to hone towards them
-	if limit < gasFloor {
-		limit = parent.GasLimit() + decay
-		if limit > gasFloor {
-			limit = gasFloor
-		}
-	} else if limit > gasCeil {
-		limit = parent.GasLimit() - decay
-		if limit < gasCeil {
-			limit = gasCeil
-		}
+	if next < vars.MinGasLimit {
+		next = vars.MinGasLimit
 	}
-	return limit
+
+	return next
 }