More specifically, the last parameter (needzero) of mallocgc is not passed down to c.nextFree, which causes the memclrNoHeapPointers function is called twice in makeslicecopy if the slice size <= 32768.
On Wednesday, August 18, 2021 at 11:06:53 PM UTC-4 tapi...@gmail.com wrote: > Spent some time on investigating this problem. It is confirmed that, when > N == 16384, the memclrNoHeapPointers function is called twice in the > Insert2 function. That means the "make+copy` optimization introduced in Go > 1.15 will perform worse than the normal route under such situation. > > On Wednesday, July 28, 2021 at 10:43:38 AM UTC-4 tapi...@gmail.com wrote: > >> >> The benchmark code: https://play.golang.org/p/IqVnVa5x9qp >> >> When N == 16384, the benchmark result: >> >> Benchmark_Insert-4 134622 8032 ns/op 32768 >> B/op 1 allocs/op >> Benchmark_Insert2-4 132049 8201 ns/op 32768 >> B/op 1 allocs/op >> >> When N == 16385, the benchmark result: >> >> Benchmark_Insert-4 118677 9374 ns/op 40960 >> B/op 1 allocs/op >> Benchmark_Insert2-4 136845 7744 ns/op 40960 >> B/op 1 allocs/op >> > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/8756b448-6718-4ee3-9f52-c83e2f606da8n%40googlegroups.com.
