4 parts
Runtime internals
What the Go runtime actually does underneath the parts of the language you write every day — scheduling, allocation, and the garbage collector — measured rather than asserted.
Series
Multi-part reads, in the order they were written to be read.
1 part
The allocator
What a heap allocation costs in Go once escape analysis has decided you are having one — size classes, the routines the compiler picks, and where the cost stops tracking the number of bytes.