From c2d9eea1f1d5bc4c49e3a97384ffcb40b7dd52bf Mon Sep 17 00:00:00 2001 From: Richard Musiol Date: Sun, 28 Apr 2019 12:16:44 +0200 Subject: [PATCH] runtime: do not use heap arena hints on wasm The address space of WebAssembly's linear memory is contiguous, so requesting specific addresses is not supported. Do not use heap arena hints so we do not have unused memory ranges. This fixes go1 benchmarks on wasm which ran out of memory since https://golang.org/cl/170950. Change-Id: I70115b18dbe43abe16dd5f57996343d97bf94760 Reviewed-on: https://go-review.googlesource.com/c/go/+/174203 Run-TryBot: Richard Musiol TryBot-Result: Gobot Gobot Reviewed-by: Cherry Zhang --- src/runtime/mem_js.go | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/src/runtime/mem_js.go b/src/runtime/mem_js.go index fc6092b2bb..7da4beda2a 100644 --- a/src/runtime/mem_js.go +++ b/src/runtime/mem_js.go @@ -41,13 +41,19 @@ var reserveEnd uintptr func sysReserve(v unsafe.Pointer, n uintptr) unsafe.Pointer { // TODO(neelance): maybe unify with mem_plan9.go, depending on how https://github.com/WebAssembly/design/blob/master/FutureFeatures.md#finer-grained-control-over-memory turns out + if v != nil { + // The address space of WebAssembly's linear memory is contiguous, + // so requesting specific addresses is not supported. We could use + // a different address, but then mheap.sysAlloc discards the result + // right away and we don't reuse chunks passed to sysFree. + return nil + } + if reserveEnd < lastmoduledatap.end { reserveEnd = lastmoduledatap.end } - if uintptr(v) < reserveEnd { - v = unsafe.Pointer(reserveEnd) - } - reserveEnd = uintptr(v) + n + v = unsafe.Pointer(reserveEnd) + reserveEnd += n current := currentMemory() needed := int32(reserveEnd/sys.DefaultPhysPageSize + 1) -- 2.48.1