On Sun, 10 March 2013 23:33:18 +0000, Al Viro wrote: > On Fri, Mar 08, 2013 at 01:26:49PM -0500, J??rn Engel wrote: > > > + files_cookie = async_schedule(exit_files_async, tsk); > > exit_mm(tsk); > > > > if (group_dead) > > @@ -990,7 +998,7 @@ void do_exit(long code) > > > > exit_sem(tsk); > > exit_shm(tsk); > > - exit_files(tsk); > > + async_synchronize_cookie(files_cookie); > > That doesn't do what you seem to think it's doing. It does *not* wait > for the completion of that sucker's execution - only the ones scheduled > before it. IOW, your exit_files_async() might very well be executed > *after* do_exit() completes and tsk gets reused.
Indeed. Maybe async_barrier() would have been a less dangerous name in the presence of people like me. Oh well! I have kernel/async.c on my list anyway. We've had a number of cases where a single bad scsi device turned the "do the scanning asynchronously" idea into a "make completely unrelated stuff synchonously wait for a broken disk" reality. Thanks for spotting this! Jörn -- The cheapest, fastest and most reliable components of a computer system are those that aren't there. -- Gordon Bell, DEC labratories -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
