cvs commit: src/sys/kern subr_turnstile.c

[John Baldwin]

jhb         2003/11/12 15:48:42 PST

  FreeBSD src repository

  Modified files:
    sys/kern             subr_turnstile.c 
  Log:
  - Close a race where a thread on another CPU could release a contested lock
    and empty its turnstile while the blocking threads still pointed to the
    turnstile.  If the thread on the first CPU blocked on a lock owned by
    one of the threads blocked on the turnstile just woken up, then the
    first CPU could try to manipulate a bogus thread queue in the turnstile
    during priority propagation.
  - Update locking notes for ts_owner and always clear ts_owner, not just
    under INVARIANTS.
  
  Tested by:      sam (1)
  
  Revision  Changes    Path
  1.134     +12 -4     src/sys/kern/subr_turnstile.c