Compiler Team Sprints

• Review some compiler-related sprints from 2021
• Presentation Goal: Share outcomes (positive and negative) and lessons learned
• Mull over: How to best direct synchronous coding efforts like sprints?

Sprints

• Shrinkmem sprint (retrospective mtg)

• wg-polonious sprints

Shrinkmem

• In the first week of March, the compiler team hosted a "shrinkmem" sprint.
• Shrinkmem Goal: reduce the amount of memory the compiler uses to bootstrap itself.
• Why: for some contributors, build times can become unbearable due to swapping.
• Current mitigation: reduce number of concurrent jobs, but this has other downsides.

Shrinkmem Positives

• Contributors came up with some interesting ideas to try out.

Shrinkmem Positives

• We were able to reduce max-rss in some of our perf.rlo tests.

Shrinkmem Positives

• The video chat calls were generally a hit and a lot of fun!

Shrinkmem Positives

• We now have docs in the rustc dev guide for doing memory profiling.

Shrinkmem Negatives

• We didn't start the week with a list of tasks to work on, so most of the first day was spent coming up with that list.

Shrinkmem Negatives

• The video calls were ad-hoc and due to timezones, some people didn't even know when they were happening.

Shrinkmem Negatives

• Some of the ideas we spent the week working on never panned out.

Shrinkmem Negatives

• Some people felt that a week was too short a sprint to make meaningful progress on a large goal like this.

wg-polonious

• The Polonious working group has done a few sprints and have generally achieved positive results!

• Sprints were 4 hours a day for one week.

• Information in this section was gathered from wg-polonious members.

wg-polonious Positives

• Working on something participants were already familiar with kept productivity high during the sprint.

wg-polonious Positives

• The sprints were mostly a way to schedule dedicated time to work on the existing set of items.

wg-polonious Positives

• Several participants pointed to the concrete set of work items prior to the start of the sprint as a key component of the success of the sprints.

wg-polonious "Negatives"

• "the biggest problem is them [sprints] not happening more"
  • Niko Matsakis

What we're going to do next time

• Plan, plan, plan!

What we're going to do next time

• We need to start the week with a set of tasks already in mind and people willing to work on them.

What we're going to do next time

• Do a better job of coordinating conversation and status updates with the participants.

What we're going to do next time

• Try to find a way to offer mentoring for interested individuals.

Social hours

• A lot of people expressed interest in having a regular video call just to chat with other people work on the project.
• Maybe we should try to set something up on a recurring basis?