Messages in this thread Patch in this message | | | Date | Fri, 6 Jun 2014 17:06:07 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2] introduce atomic_pointer to fix a race condition in cancelable mcs spinlocks |
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On Mon, Jun 02, 2014 at 10:09:35AM -0700, Linus Torvalds wrote: > On Mon, Jun 2, 2014 at 9:25 AM, Peter Zijlstra <peterz@infradead.org> wrote: > > > > And I can't say I'm a particular fan of these ops either, as alternative > > I'm almost inclined to just exclude parisc from using opt spinning. > > Please do.
Something like so; if the rwsem stuff lands in .15 we need more for that, it doesn't have a convenient CONFIG symbol like this.
Linus will you take this from email, or should I get it through tip/locking/urgent or so?
--- Subject: locking, mutex: Disable optimistic spinning for PA-RISC
PA-RISC's cmpxchg is not save against normal stores and the code used for optimistic spinning is known broken because of this.
Disable for now.
Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> --- kernel/Kconfig.locks | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index 35536d9c0964..9c239e080c2d 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -222,7 +222,7 @@ endif config MUTEX_SPIN_ON_OWNER def_bool y - depends on SMP && !DEBUG_MUTEXES + depends on SMP && !DEBUG_MUTEXES && !PARISC config ARCH_USE_QUEUE_RWLOCK bool
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