linux/arch/m68knommu
Peter Zijlstra aa02cd2d9b xtime_lock vs update_process_times
Commit d3d74453c3 ("hrtimer: fixup the
HRTIMER_CB_IRQSAFE_NO_SOFTIRQ fallback") broke several archs, and since
only Russell bothered to merge the fix, and Greg to ACK his arch, I'm
sending this for merger.

I have confirmation that the Alpha bit results in a booting kernel.
That leaves: blackfin, frv, sh and sparc untested.

The deadlock in question was found by Russell:

  IRQ handle
    -> timer_tick() - xtime seqlock held for write
      -> update_process_times()
        -> run_local_timers()
          -> hrtimer_run_queues()
            -> hrtimer_get_softirq_time() - tries to get a read lock

Now, Thomas assures me the fix is trivial, only do_timer() needs to be
done under the xtime_lock, and update_process_times() can savely be
removed from under it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Greg Ungerer <gerg@uclinux.org>
CC: Richard Henderson <rth@twiddle.net>
CC: Bryan Wu <bryan.wu@analog.com>
CC: David Howells <dhowells@redhat.com>
CC: Paul Mundt <lethal@linux-sh.org>
CC: William Irwin <wli@holomorphy.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-13 13:29:25 -08:00
..
kernel xtime_lock vs update_process_times 2008-02-13 13:29:25 -08:00
lib Remove inclusions of <linux/autoconf.h> 2008-02-06 10:41:00 -08:00
mm m68knommu: mark mem init functions as __init 2007-10-23 20:45:44 -07:00
platform m68knommu: remove dead timer int pending code 2008-02-01 21:02:04 +11:00
Kconfig ide: introduce HAVE_IDE 2008-02-09 10:46:40 +01:00
Kconfig.debug m68knommu: removing config variable DUMPTOFLASH 2008-02-05 09:44:21 -08:00
Makefile m68knommu: modify Makefiles to support common coldfire directory 2008-02-01 20:58:10 +11:00
defconfig m68knommu: removing config variable DUMPTOFLASH 2008-02-05 09:44:21 -08:00