Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [PATCH] Fix x86_64 _spin_lock_irqsave() | Date | Thu, 24 Aug 2006 13:32:40 +0200 |
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On Thursday 24 August 2006 13:04, Suleiman Souhlal wrote: > Andi Kleen wrote: > > Edward Falk <efalk@google.com> writes: > > > > > >>Add spin_lock_string_flags and _raw_spin_lock_flags() to > >>asm-x86_64/spinlock.h so that _spin_lock_irqsave() has the same > >>semantics on x86_64 as it does on i386 and does *not* have interrupts > >>disabled while it is waiting for the lock. > > > > > > Did it fix anything for you? > > I think this was to work around the fact that some buggy drivers try to > grab spinlocks without disabling interrupts when they should, which > would cause deadlocks when trying to rendez-vous every cpu via IPIs.
That doesn't help them at all because they could then deadlock later.
In theory it is just a quite cheesy way to make lock contended code work a little better, but I was not aware of it actually helping in practice.
-Andi
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