From 95c354fe9f7d6decc08a92aa26eb233ecc2155bf Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Wed, 30 Jan 2008 13:31:20 +0100 Subject: spinlock: lockbreak cleanup The break_lock data structure and code for spinlocks is quite nasty. Not only does it double the size of a spinlock but it changes locking to a potentially less optimal trylock. Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a __raw_spin_is_contended that uses the lock data itself to determine whether there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is not set. Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to decouple it from the spinlock implementation, and make it typesafe (rwlocks do not have any need_lockbreak sites -- why do they even get bloated up with that break_lock then?). Signed-off-by: Nick Piggin Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/sparc64/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/sparc64') diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig index 10b212a1f9f..1e25bce0366 100644 --- a/arch/sparc64/Kconfig +++ b/arch/sparc64/Kconfig @@ -200,6 +200,11 @@ config US2E_FREQ If in doubt, say N. # Global things across all Sun machines. +config GENERIC_LOCKBREAK + bool + default y + depends on SMP && PREEMPT + config RWSEM_GENERIC_SPINLOCK bool -- cgit v1.2.3