• Austin Clements's avatar
    runtime: mark extra M's G as dead when not in use · 4e7067cd
    Austin Clements authored
    Currently the extra Ms created for cgo callbacks have a corresponding
    G that's kept in syscall state with only a call to goexit on its
    stack. This leads to confusing output from runtime.NumGoroutines and
    in tracebacks:
    
    goroutine 17 [syscall, locked to thread]:
    runtime.goexit()
    	.../src/runtime/asm_amd64.s:2197 +0x1
    
    Fix this by putting this goroutine into state _Gdead when it's not in
    use instead of _Gsyscall. To keep the goroutine counts correct, we
    also add one to sched.ngsys while the goroutine is in _Gdead. The
    effect of this is as if the goroutine simply doesn't exist when it's
    not in use.
    
    Fixes #16631.
    Fixes #16714.
    
    Change-Id: Ieae08a2febd4b3d00bef5c23fd6ca88fb2bb0087
    Reviewed-on: https://go-review.googlesource.com/45030
    Run-TryBot: Austin Clements <austin@google.com>
    TryBot-Result: Gobot Gobot <gobot@golang.org>
    Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
    4e7067cd
proc.go 125 KB