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authorNick Piggin <npiggin@suse.de>2008-01-30 13:31:20 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:31:20 +0100
commit95c354fe9f7d6decc08a92aa26eb233ecc2155bf (patch)
treeec9267032ea875e84216cfb20acb2cfc7c62149f /arch/x86/Kconfig
parenta95d67f87e1a5f1b4429be3ba3bf7b4051657908 (diff)
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 <npiggin@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/Kconfig')
-rw-r--r--arch/x86/Kconfig4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 23936301db5..db434f8171d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -19,6 +19,10 @@ config X86_64
config X86
def_bool y
+config GENERIC_LOCKBREAK
+ def_bool y
+ depends on SMP && PREEMPT
+
config GENERIC_TIME
def_bool y