diff options
Diffstat (limited to 'src/runtime/stack.go')
| -rw-r--r-- | src/runtime/stack.go | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/src/runtime/stack.go b/src/runtime/stack.go index a338708d76..d809820b07 100644 --- a/src/runtime/stack.go +++ b/src/runtime/stack.go @@ -1214,15 +1214,18 @@ func isShrinkStackSafe(gp *g) bool { if gp.parkingOnChan.Load() { return false } - // We also can't copy the stack while tracing is enabled, and - // gp is in _Gwaiting solely to make itself available to suspendG. + // We also can't copy the stack while a gp is in _Gwaiting solely + // to make itself available to suspendG. + // // In these cases, the G is actually executing on the system - // stack, and the execution tracer may want to take a stack trace - // of the G's stack. Note: it's safe to access gp.waitreason here. - // We're only checking if this is true if we took ownership of the + // stack, and the execution tracer, mutex profiler, etc. may want + // to take a stack trace of the G's stack. + // + // Note: it's safe to access gp.waitreason here. + // We're only calling isShrinkStackSafe if we took ownership of the // G with the _Gscan bit. This prevents the goroutine from transitioning, // which prevents gp.waitreason from changing. - if traceEnabled() && readgstatus(gp)&^_Gscan == _Gwaiting && gp.waitreason.isWaitingForSuspendG() { + if readgstatus(gp)&^_Gscan == _Gwaiting && gp.waitreason.isWaitingForSuspendG() { return false } return true @@ -1258,12 +1261,6 @@ func shrinkstack(gp *g) { if debug.gcshrinkstackoff > 0 { return } - f := findfunc(gp.startpc) - if f.valid() && f.funcID == abi.FuncID_gcBgMarkWorker { - // We're not allowed to shrink the gcBgMarkWorker - // stack (see gcBgMarkWorker for explanation). - return - } oldsize := gp.stack.hi - gp.stack.lo newsize := oldsize / 2 |