geth -pricelimit not very useful after EIP1559

[Kzenox7]

I'd like to raise a potential issue with the geth -pricelimit parameter and EIP1559.

From my observations it looks like this parameter only checks the value of MaxPriorityFeePerGas instead of something more useful like MaxFeePerGas. I believe that the -pricelimit is now fairly useless since MaxPriorityFeePerGas is almost always around 1 to 3 Gwei even though the total tx gas price could easily be 100+ Gwei.

Due to this behaviour I have set this parameter to 1 Gwei which causes the geth node to receive a huge amount of low gas pre-EIP1559 tx's that have been pending for months.

It is not in alignment with the way it works for pre-EIP1559 transactions.

[rjl493456442]

It's an interesting issue! I mark it as triage to discuss with team.

[fjl]

The issue is: in TxPool, the value of -pricelimit is stored in the field gasPrice. We apply this check when validating incoming transactions:

go-ethereum/core/tx_pool.go

Lines 624 to 627 in 03bc8b7

	// Drop non-local transactions under our own minimal accepted gas price or tip
	if !local && tx.GasTipCapIntCmp(pool.gasPrice) < 0 {
	return ErrUnderpriced
	}

However, we apply a different check when selecting transactions for mining:

go-ethereum/core/tx_pool.go

Lines 547 to 549 in 03bc8b7

	if tx.EffectiveGasTipIntCmp(pool.gasPrice, pool.priced.urgent.baseFee) < 0 {
	txs = txs[:i]
	break

I think this issue could be resolved by making the check in validateTx also use the EffectiveGasTipIntCmp method.

[XWJACK]

The issue is: in TxPool, the value of -pricelimit is stored in the field gasPrice. We apply this check when validating incoming transactions:

go-ethereum/core/tx_pool.go

Lines 624 to 627 in 03bc8b7

	// Drop non-local transactions under our own minimal accepted gas price or tip
	if !local && tx.GasTipCapIntCmp(pool.gasPrice) < 0 {
	return ErrUnderpriced
	}

However, we apply a different check when selecting transactions for mining:

go-ethereum/core/tx_pool.go

Lines 547 to 549 in 03bc8b7

	if tx.EffectiveGasTipIntCmp(pool.gasPrice, pool.priced.urgent.baseFee) < 0 {
	txs = txs[:i]
	break

I think this issue could be resolved by making the check in validateTx also use the EffectiveGasTipIntCmp method.

pool.gasPrice is config by pricelimit.

go-ethereum/core/tx_pool.go

Line 300 in cc87cbd

gasPrice: new(big.Int).SetUint64(config.PriceLimit),

baseFee will always changed by tx pool . so if you do that, users will not able to send tx below baseFee rather than pricelimit. highly recommended revert this pr #23855.

go-ethereum/core/tx_list.go

Line 424 in cc87cbd

baseFee *big.Int // heap should always be re-sorted after baseFee is changed