runtime: combine small NoScan allocations Combine NoScan allocations < 16 bytes into a single memory block. Reduces number of allocations on json/garbage benchmarks by 10+%. json-1 allocated 8039872 7949194 -1.13% allocs 105774 93776 -11.34% cputime 156200000 100700000 -35.53% gc-pause-one 4908873 3814853 -22.29% gc-pause-total 2748969 2899288 +5.47% rss 52674560 43560960 -17.30% sys-gc 3796976 3256304 -14.24% sys-heap 43843584 35192832 -19.73% sys-other 5589312 5310784 -4.98% sys-stack 393216 393216 +0.00% sys-total 53623088 44153136 -17.66% time 156193436 100886714 -35.41% virtual-mem 256548864 256540672 -0.00% garbage-1 allocated 2996885 2932982 -2.13% allocs 62904 55200 -12.25% cputime 17470000 17400000 -0.40% gc-pause-one 932757485 925806143 -0.75% gc-pause-total 4663787 4629030 -0.75% rss 1151074304 1133670400 -1.51% sys-gc 66068352 65085312 -1.49% sys-heap 1039728640 1024065536 -1.51% sys-other 38038208 37485248 -1.45% sys-stack 8650752 8781824 +1.52% sys-total 1152485952 1135417920 -1.48% time 17478088 17418005 -0.34% virtual-mem 1343709184 1324204032 -1.45% LGTM=iant, bradfitz R=golang-codereviews, dave, iant, rsc, bradfitz CC=golang-codereviews, khr https://golang.org/cl/38750047
diff --git a/test/deferfin.go b/test/deferfin.go index fa5a933..8037291 100644 --- a/test/deferfin.go +++ b/test/deferfin.go
@@ -34,17 +34,17 @@ for i := 0; i < N; i++ { go func() { defer wg.Done() - v := new(int) + v := new(string) f := func() { - if *v != 0 { + if *v != "" { panic("oops") } } - if *v != 0 { + if *v != "" { // let the compiler think f escapes sink = f } - runtime.SetFinalizer(v, func(p *int) { + runtime.SetFinalizer(v, func(p *string) { atomic.AddInt32(&count, -1) }) defer f()