cvs commit: src/sys/kern imgact_elf.c kern_fork.c kern_kse.c kern_thr.c kern_thread.c src/sys/sys proc.h

[Marcel Moolenaar]

marcel      2004-06-26 18:58:22 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             imgact_elf.c kern_fork.c kern_kse.c 
                         kern_thr.c kern_thread.c 
    sys/sys              proc.h 
  Log:
  Allocate TIDs in thread_init() and deallocate them in thread_fini().
  The overhead of unconditionally allocating TIDs (and likewise,
  unconditionally deallocating them), is amortized across multiple
  thread creations by the way UMA makes it possible to have type-stable
  storage.
  Previously the cost was kept down by having threads created as part
  of a fork operation use the process' PID as the TID. While this had
  some nice properties, it also introduced complexity in the way TIDs
  were allocated. Most importantly, by using the type-stable storage
  that UMA gives us this was also unnecessary.
  
  This change affects how core dumps are created and in particular how
  the PRSTATUS notes are dumped. Since we don't have a thread with a
  TID equalling the PID, we now need a different way to preserve the
  old and previous behavior. We do this by having the given thread (i.e.
  the thread passed to the core dump code in td) dump it's state first
  and fill in pr_pid with the actual PID. All other threads will have
  pr_pid contain their TIDs. The upshot of all this is that the debugger
  will now likely select the right LWP (=TID) as the initial thread.
  
  Credits to: julian@ for spotting how we can utilize UMA.
  Thanks to: all who provided julian@ with test results.
  
  Revision  Changes    Path
  1.152     +31 -33    src/sys/kern/imgact_elf.c
  1.227     +0 -1      src/sys/kern/kern_fork.c
  1.182     +1 -3      src/sys/kern/kern_kse.c
  1.20      +0 -1      src/sys/kern/kern_thr.c
  1.185     +57 -71    src/sys/kern/kern_thread.c
  1.382     +0 -1      src/sys/sys/proc.h