Inconsistent CU charging for ELF size across loaders

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Problem

While debugging into LiteSVM/litesvm#297 I would like to share the following observation.
CPI Callee programs charge differently according to the loader they're loaded with. The code snippet under scrutiny -

agave/program-runtime/src/cpi.rs

Lines 1089 to 1098 in 8d074a7

	#[allow(deprecated)]
	if callee_account.is_executable() {
	// Use the known account
	consume_compute_meter(
	invoke_context,
	(callee_account.get_data().len() as u64)
	.checked_div(invoke_context.get_execution_cost().cpi_bytes_per_unit)
	.unwrap_or(u64::MAX),
	)?;
	} else if let Some(caller_account_index) =

• If they're loaded with BPFLoaderUpgradeab1e11111111111111111111111 (two accounts used here - program metadata + program data) effectively it's the program metadata account size / 250 (cpi_bytes_per_unit) which is 36 (the metadata account) / 250 = 0 CUs that is charged. For example this is the case with https://solscan.io/account/TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb
• now if the program is loaded with BPFLoader2111111111111111111111111111111111, for example https://solscan.io/account/ATokenGPvbdGVxr1b2hvZbsiqW5xWH25efTNsLJA8knL, then effectively it has one single program account holding the data and in the snippet in question get_data().len() it's 105032 bytes / 250 = 420 CUs

This seems unfair. Now provided that the majority of deployed programs use BPFLoaderUpgradeab1e11111111111111111111111 and that 36 / 250 calculation always results to 0 and hence nothing is charged here why the BPFLoader2111111111111111111111111111111111 loaded programs get so badly treated with full_program_len / 250?

Proposed Solution

Isn't it fair to actually remove the consume_compute_meter call here? If you like I can file a PR doing the change but I believe it's first best to share as you have more context.

cc @Lichtso @LucasSte @nagisa @buffalojoec @kevinheavey

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Some history - solana-labs#24396

[Lichtso]

Yep known issue, only loader-v3 does not pay for the ELF size. See SIMD discussions:

• RFC: Loader V3: Fix or Replace solana-foundation/solana-improvement-documents#423
• SIMD-0167: Loader-v4 solana-foundation/solana-improvement-documents#167