Avoid clash between os.WRUSAGE and Linux's WALL flag.

R=rsc
APPROVED=rsc
DELTA=5  (4 added, 0 deleted, 1 changed)
OCL=31564
CL=31567

diff --git a/src/pkg/os/exec.go b/src/pkg/os/exec.go
index a7430ef7f77ce7f0254d88ca859de63dd427f534..9ae81c0d5a76a9314b3ead458674b2353dfeaad6 100644 (file)
--- a/src/pkg/os/exec.go
+++ b/src/pkg/os/exec.go
@@ -70,9 +70,13 @@ const (
        WNOHANG = syscall.WNOHANG;      // Don't wait if no process has exited.
        WSTOPPED = syscall.WSTOPPED;    // If set, status of stopped subprocesses is also reported.
        WUNTRACED = WSTOPPED;
-       WRUSAGE = 1<<30;        // Record resource usage.
+       WRUSAGE = 1<<20;        // Record resource usage.
 )
 
+// WRUSAGE must not be too high a bit, to avoid clashing with Linux's
+// WCLONE, WALL, and WNOTHREAD flags, which sit in the top few bits of
+// the options
+
 // Wait waits for process pid to exit or stop, and then returns a
 // Waitmsg describing its status and an Error, if any. The options
 // (WNOHANG etc.) affect the behavior of the Wait call.