linux/arch/sh
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
..
boards Rename: linux/pata_platform.h to linux/ata_platform.h 2008-02-06 06:54:17 -05:00
boot sh: Fix up KERNEL_ENTRY calculation for uImage. 2008-01-28 13:19:01 +09:00
cchips sh: remove voyagergx 2008-01-28 13:19:03 +09:00
configs sh: Add support for SDK7780 board. 2008-01-28 13:19:04 +09:00
drivers PCI: Kconfig help: don't refer to the PCI-HOWTO 2008-02-01 15:04:26 -08:00
kernel xtime_lock vs update_process_times 2008-02-13 13:29:25 -08:00
lib sh: Explicit alignment for PAGE_SIZE in copy/clear_page(). 2008-01-28 13:18:58 +09:00
lib64 sh: comment tidying for sh64->sh migration. 2008-01-28 13:18:58 +09:00
math-emu sh: Fix up the math-emu build. 2007-06-11 15:57:42 +09:00
mm Introduce flags for reserve_bootmem() 2008-02-07 08:42:25 -08:00
oprofile sh: Add -Werror for clean directories. 2007-11-07 11:13:55 +09:00
tools sh: Kill off dead HS771RVoIP board support. 2008-01-28 13:19:03 +09:00
Kconfig ide: introduce HAVE_IDE 2008-02-09 10:46:40 +01:00
Kconfig.cpu sh: Use def_bool where possible. 2008-01-28 13:19:00 +09:00
Kconfig.debug sh: Add support for SH7763 CPU subtype. 2008-01-28 13:19:02 +09:00
Makefile sh: Add support for SDK7780 board. 2008-01-28 13:19:04 +09:00