Re: PG 15 (and to a smaller degree 14) regression due to ExprEvalStep size

On Fri, 22 Jul 2022 at 15:22, Amit Langote <amitlangote09@gmail.com> wrote:
> BTW, the only way I found to *forcefully* exercise llvm_compile_expr()
> is to add `set jit_above_cost to 0` at the top of the test file, or
> are we missing a force_jit_mode, like there is force_parallel_mode?

I don't think we'd need any setting to hide the JIT counters from
EXPLAIN ANALYZE since those only show with COSTS ON, which we tend not
to do.

I think for testing, you could just zero all the jit*above_cost GUCs.

If you look at the config_extra in [1], you'll see that animal runs
the tests with modified JIT parameters.

BTW, I was working on code inside llvm_compile_expr() a few days ago
and I thought I'd gotten the new evaluation steps I was adding correct
as it worked fine with jit_above_cost=0, but on further testing, it
crashed with jit_inline_above_cost=0. Might be worth doing both to see
if everything works as intended.

David

[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=desmoxytes&dt=2022-07-22%2003%3A04%3A03