1. 19 Dec, 2004 8 commits
  2. 11 Dec, 2004 1 commit
  3. 06 Dec, 2004 1 commit
  4. 26 Nov, 2004 7 commits
  5. 25 Nov, 2004 3 commits
  6. 23 Nov, 2004 3 commits
  7. 22 Nov, 2004 15 commits
  8. 21 Nov, 2004 2 commits
    • Benjamin Herrenschmidt's avatar
      [PATCH] del_timer() vs. mod_timer() SMP race · 8c2bfc5b
      Benjamin Herrenschmidt authored
      We just spent some days fighting a rare race in one of the distro's who backported
      some of timer.c from 2.6 to 2.4 (though they missed a bit).
      
      The actual race we found didn't happen in 2.6 _but_ code inspection showed that a
      similar race is still present in 2.6, explanation below:
      
      Code removing a timer from a list (run_timers or del_timer) takes that CPU list
      lock, does list_del, then timer->base = NULL.
      
      It is mandatory that this timer->base = NULL is visible to other CPUs only after
      the list_del() is complete. If not, then mod timer could see it NULL, thus take it's
      own CPU list lock and not the one for the CPU the timer was beeing removed from the
      list, and thus the list_add in mod_timer() could race with the list_del() from
      run_timers() or del_timer().
      
      Our race happened with run_timers(), which _DOES_ contain a proper smp_wmb() in the
      right spot in 2.6, but didn't in the "backport" we were fighting with.
      
      However, del_timer() doesn't have such a barrier, and thus is subject to this race in
      2.6 as well. This patch fixes it.
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8c2bfc5b
    • Benjamin Herrenschmidt's avatar
      [PATCH] ppc64: Fix early serial setup baud rate · 6621ad71
      Benjamin Herrenschmidt authored
      The "udbg" code used on ppc64 for early consoles including early serial
      console recently got a new "default speed" option. This was implemented
      as a switch case that missed a few important cases, one beeing necessary
      for a board beeing released soon.
      
      This patch fixes it by using the proper division to calculate the dll
      value for the uart instead of that bogus switch/case.
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      6621ad71