Docs: Add Rugged GVL issue and rbspy to Sidekiq troubleshooting docs
What does this MR do?
Two additions to the Sidekiq troubleshooting docs:
- Add a note on using
rbspyto profile Sidekiq - Note that Rugged locking the GVL may cause performance issues.
The latter was noted as a possibility in the past, we've now seen this occur in the wild and trigger a customer emergency.
Related issues
Edited by Will Chandler (ex-GitLab)