diff options
| author | Russ Cox <rsc@golang.org> | 2011-02-23 15:51:20 -0500 |
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2011-02-23 15:51:20 -0500 |
| commit | b5dfac45ba29f12cbc86925ab7c7cd018f87f4fe (patch) | |
| tree | 84da18dce1a9135bbf30f3bee0abcd86a582c6fb /src/pkg/runtime/malloc.goc | |
| parent | 59ce067da8d9e7d968e51f31fb532ed2369f205a (diff) | |
| download | go-b5dfac45ba29f12cbc86925ab7c7cd018f87f4fe.tar.xz | |
runtime: always run stackalloc on scheduler stack
Avoids deadlocks like the one below, in which a stack split happened
in order to call lock(&stacks), but then the stack unsplit cannot run
because stacks is now locked.
The only code calling stackalloc that wasn't on a scheduler
stack already was malg, which creates a new goroutine.
runtime.futex+0x23 /home/rsc/g/go/src/pkg/runtime/linux/amd64/sys.s:139
runtime.futex()
futexsleep+0x50 /home/rsc/g/go/src/pkg/runtime/linux/thread.c:51
futexsleep(0x5b0188, 0x300000003, 0x100020000, 0x4159e2)
futexlock+0x85 /home/rsc/g/go/src/pkg/runtime/linux/thread.c:119
futexlock(0x5b0188, 0x5b0188)
runtime.lock+0x56 /home/rsc/g/go/src/pkg/runtime/linux/thread.c:158
runtime.lock(0x5b0188, 0x7f0d27b4a000)
runtime.stackfree+0x4d /home/rsc/g/go/src/pkg/runtime/malloc.goc:336
runtime.stackfree(0x7f0d27b4a000, 0x1000, 0x8, 0x7fff37e1e218)
runtime.oldstack+0xa6 /home/rsc/g/go/src/pkg/runtime/proc.c:705
runtime.oldstack()
runtime.lessstack+0x22 /home/rsc/g/go/src/pkg/runtime/amd64/asm.s:224
runtime.lessstack()
----- lessstack called from goroutine 2 -----
runtime.lock+0x56 /home/rsc/g/go/src/pkg/runtime/linux/thread.c:158
runtime.lock(0x5b0188, 0x40a5e2)
runtime.stackalloc+0x55 /home/rsc/g/go/src/pkg/runtime/malloc.c:316
runtime.stackalloc(0x1000, 0x4055b0)
runtime.malg+0x3d /home/rsc/g/go/src/pkg/runtime/proc.c:803
runtime.malg(0x1000, 0x40add9)
runtime.newproc1+0x12b /home/rsc/g/go/src/pkg/runtime/proc.c:854
runtime.newproc1(0xf840027440, 0x7f0d27b49230, 0x0, 0x49f238, 0x40, ...)
runtime.newproc+0x2f /home/rsc/g/go/src/pkg/runtime/proc.c:831
runtime.newproc(0x0, 0xf840027440, 0xf800000010, 0x44b059)
...
R=r, r2
CC=golang-dev
https://golang.org/cl/4216045
Diffstat (limited to 'src/pkg/runtime/malloc.goc')
| -rw-r--r-- | src/pkg/runtime/malloc.goc | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/pkg/runtime/malloc.goc b/src/pkg/runtime/malloc.goc index abbf63b931..41060682eb 100644 --- a/src/pkg/runtime/malloc.goc +++ b/src/pkg/runtime/malloc.goc @@ -394,6 +394,12 @@ runtime·stackalloc(uint32 n) { void *v; + // Stackalloc must be called on scheduler stack, so that we + // never try to grow the stack during the code that stackalloc runs. + // Doing so would cause a deadlock (issue 1547). + if(g != m->g0) + runtime·throw("stackalloc not on scheduler stack"); + if(m->mallocing || m->gcing || n == FixedStack) { runtime·lock(&stacks); if(stacks.size == 0) |