runtime: VirtualAlloc of 4294967296 bytes failed with errno=1455 on windows/amd64 go 1.13.4

[glycerine]

I just encountered a similar panic to #33716 . I am running Go 1.13.4 windows/amd64. My windows VM has 5GB of RAM. Go tried to allocate 4GB of RAM and crashed. This is a big long running program (had been running for about 24 hours at the point of crash) so no easy repro test case available immediately.

It seems rather unreasonable for Go to ask for that much memory on a 5GB box.

runtime: VirtualAlloc of 4294967296 bytes failed with errno=1455
fatal error: out of memory

runtime stack:
runtime.throw(0x2977e71, 0xd)
c:/go/src/runtime/panic.go:774 +0x79
runtime.sysUsed(0xc280b26000, 0x100000000)
c:/go/src/runtime/mem_windows.go:83 +0x230
runtime.(*mheap).allocSpanLocked(0x4087660, 0x80000, 0x40ab448, 0x1210fda0)
c:/go/src/runtime/mheap.go:1228 +0x203
runtime.(*mheap).alloc_m(0x4087660, 0x80000, 0x101, 0x1210fdd0)
c:/go/src/runtime/mheap.go:1022 +0xd0
runtime.(*mheap).alloc.func1()
c:/go/src/runtime/mheap.go:1093 +0x53
runtime.(*mheap).alloc(0x4087660, 0x80000, 0x10101, 0xc000048000)
c:/go/src/runtime/mheap.go:1092 +0x91
runtime.largeAlloc(0xfffffe00, 0xc000040101, 0xc000056000)
c:/go/src/runtime/malloc.go:1138 +0x9e
runtime.mallocgc.func1()
c:/go/src/runtime/malloc.go:1033 +0x4d
runtime.systemstack(0x0)
c:/go/src/runtime/asm_amd64.s:370 +0x6b
runtime.mstart()
c:/go/src/runtime/proc.go:1146

goroutine 1 [running]:
runtime.systemstack_switch()
c:/go/src/runtime/asm_amd64.s:330 fp=0xc0003e9108 sp=0xc0003e9100 pc=0x464f10
runtime.mallocgc(0xfffffe00, 0x26064a0, 0x1, 0xc0003e91d0)
c:/go/src/runtime/malloc.go:1032 +0x8d4 fp=0xc0003e91a8 sp=0xc0003e9108 pc=0x411344
runtime.makeslice(0x26064a0, 0xfffffe00, 0xfffffe00, 0x0)
c:/go/src/runtime/slice.go:49 +0x73 fp=0xc0003e91d8 sp=0xc0003e91a8 pc=0x44c4b3
bytes.makeSlice(0xfffffe00, 0x0, 0x0, 0x0)
c:/go/src/bytes/buffer.go:229 +0x7e fp=0xc0003e9240 sp=0xc0003e91d8 pc=0x535c2e
bytes.(*Buffer).grow(0xc0003e9368, 0x200, 0x40000000)
c:/go/src/bytes/buffer.go:142 +0x162 fp=0xc0003e9290 sp=0xc0003e9240 pc=0x535562
bytes.(*Buffer).ReadFrom(0xc0003e9368, 0x2e01ce0, 0xc0000060e0, 0x2917ea0, 0xc00006e120, 0xc0001
be8b8)
c:/go/src/bytes/buffer.go:202 +0x52 fp=0xc0003e9300 sp=0xc0003e9290 pc=0x535a12
io/ioutil.readAll(0x2e01ce0, 0xc0000060e0, 0x200, 0x0, 0x0, 0x0, 0x0, 0x0)
c:/go/src/io/ioutil/ioutil.go:36 +0x107 fp=0xc0003e93a0 sp=0xc0003e9300 pc=0x54c927
io/ioutil.ReadAll(...)
c:/go/src/io/ioutil/ioutil.go:45
...

[mknyszek]

I replied on the other issue, but copying here for visibility:

@glycerine AFAICT your application ran out of memory. It looks like your application tried to read more than 4 GiB from an io.Reader and the OS determined it didn't have enough memory left to satisfy the allocation (note that the bytes.Buffer grows, calling makeSlice with an argument of 4294966784 bytes, which was then rounded up to 4 GiB even because it's allocating at a page granularity).

[mknyszek]

To be clear, the runtime is asking the OS for 4 GiB of memory on behalf of your application. The request is ultimately coming from there. Please let me know if there are any further issues, though.

[glycerine]

I tried running the GC manually more often, and that seems to have fixed it. So closing.