Only 54 µs of that 68 ms collection was a pause
A gctrace line carries eleven numbers. Two are stop-the-world, one has a third of the GC subtracted out of it, and the biggest one is not a pause at all.
#gc
Articles tagged “gc”
4 articlesRuntime internals
Green Tea cut my GC time 63%, and raised it 39%
One heap shape lost 63% of its collector CPU and gained 14% throughput. Another gained 39% collector CPU and lost nothing. Same flag, same binary pair, same machine.
The GOGC I set next to GOMEMLIMIT never fired
GOGC=100 with a 256 MiB limit produced exactly what GOGC=off produced: same collections, same CPU share, same throughput. The tighter rule binds, the other goes quiet.
sync.Pool survives one GC, not two
A pool holding 100 objects lost none across one collection and all 100 across two. Here is the victim cache, and what it costs at 122,000 ops per millisecond.