Stream: t-compiler/wg-prioritization/alerts

Topic: I-prioritize #76247 Large performance drop in compiled bina…


triagebot (Sep 02 2020 at 14:02, on Zulip):

@WG-prioritization/alerts issue #76247 has been requested for prioritization.

Procedure

apiraino (Sep 02 2020 at 15:10, on Zulip):

This perf. loss is different from what reported in (for example) in https://github.com/rust-lang/rust/issues/75992, right? Should we invoke a bisection on this issue?

Joshua Nelson (Sep 02 2020 at 15:12, on Zulip):

yes, this is about runtime and the other is about compile time

Joshua Nelson (Sep 02 2020 at 15:12, on Zulip):

I think we're going to find it was because of the llvm 10 bump, but a bisection wouldn't hurt

apiraino (Sep 02 2020 at 15:13, on Zulip):

ok thanks. Adding bisect label

Joshua Nelson (Sep 02 2020 at 15:13, on Zulip):

also this is a regression from 1.44 -> 1.45 and the otherwas 1.45 -> 1.46

Santiago Pastorino (Sep 02 2020 at 16:02, on Zulip):

@Joshua Nelson yeah pretty sure this is llvm, was on 1.44 to 1.45 when LLVM upgrade to 10 was done?

Santiago Pastorino (Sep 02 2020 at 16:02, on Zulip):

I saw that 11 doesn't fix the situation

Santiago Pastorino (Sep 02 2020 at 16:02, on Zulip):

we should mainly ping llvm crew

Joshua Nelson (Sep 02 2020 at 16:03, on Zulip):

https://github.com/rust-lang/rust/pull/67759/commits/9f128235b49199f766f40df08c8a7eb25e143ae9 says the first tag it's in is 1.45 so yeah

Santiago Pastorino (Sep 02 2020 at 16:03, on Zulip):

ok

Santiago Pastorino (Sep 02 2020 at 16:04, on Zulip):

if we were to prioritize this, I'd say P-high

Santiago Pastorino (Sep 02 2020 at 16:04, on Zulip):

what others think?

Santiago Pastorino (Sep 02 2020 at 16:04, on Zulip):

but on the other hand there's no much we can do about this :)

Santiago Pastorino (Sep 02 2020 at 16:04, on Zulip):

so it's meh I guess

Santiago Pastorino (Sep 02 2020 at 16:05, on Zulip):

well, we can do something, the llvm crew can patch LLVM :P

Santiago Pastorino (Sep 02 2020 at 16:05, on Zulip):

or we could push a bit more there

Santiago Pastorino (Sep 02 2020 at 16:05, on Zulip):

maybe this is worth a nomination?

Joshua Nelson (Sep 02 2020 at 16:05, on Zulip):

I think nomination and P-medium maybe?

Joshua Nelson (Sep 02 2020 at 16:06, on Zulip):

the code still works, it's just slower

Santiago Pastorino (Sep 02 2020 at 16:10, on Zulip):

well yeah but hmm

Santiago Pastorino (Sep 02 2020 at 16:10, on Zulip):

let's wait for another person that suggest a priority to untie this :)

Santiago Pastorino (Sep 02 2020 at 16:11, on Zulip):

@WG-prioritization :point_up:

o0Ignition0o - Jeremy Lempereur (Sep 02 2020 at 16:35, on Zulip):

I d go p-high as well because the drop seems huge, even though there’s not much we can do

apiraino (Sep 02 2020 at 16:40, on Zulip):

applying label P-high :thumbs_up:

triagebot (Sep 02 2020 at 16:41, on Zulip):

Issue #76247's prioritization request has been removed.

Santiago Pastorino (Sep 02 2020 at 17:31, on Zulip):

apiraino said:

applying label P-high :thumbs_up:

thanks, added a comment pointing to the discussion here

Last update: Apr 10 2021 at 23:00UTC