On Thu, Mar 10, 2022 at 9:37 AM Justin Pryzby <pry...@telsasoft.com> wrote: > On Wed, Mar 09, 2022 at 10:12:54AM -0800, Andres Freund wrote: > > On 2022-03-09 11:47:23 -0600, Justin Pryzby wrote: > > > I'm curious what you think of this patch. > > > > > > It makes check-world on freebsd over 30% faster - saving 5min. > > > > That's nice! While -Og makes interactive debugging noticeably harder IME, > > it's > > not likely to be a large enough difference just for backtraces etc. > > Yeah. gcc(1) claims that -Og can improve debugging.
Wow, I see the effect on Cirrus -- test_world ran in 8:55 instead of 12:43 when I tried (terrible absolute times, but fantastic improvement!). Hmm, on my local FreeBSD 13 box I saw 5:07 -> 5:03 with this change. My working theory had been that there is something bad happening in the I/O stack under concurrency making FreeBSD on Cirrus/GCP very slow (ie patterns to stall on slow cloud I/O waits, something I hope to dig into when post-freeze round tuits present themselves), but that doesn't gel with this huge improvement from noodling with optimiser details, and I don't know why I don't see something similar locally. I'm confused. Just BTW it's kinda funny that we say -ggdb for macOS and then we use lldb to debug cores in cores_backtrace.sh. I suppose it would be more correct to say -glldb, but doubt it matters much...