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>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index de211ac..77201d3 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -91,6 +91,11 @@
bool
default y
+config GENERIC_LOCKBREAK
+ bool
+ default y
+ depends on SMP && PREEMPT
+
config RWSEM_GENERIC_SPINLOCK
bool
default y
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index bef4772..4a81b7f 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -42,6 +42,11 @@
config SWIOTLB
bool
+config GENERIC_LOCKBREAK
+ bool
+ default y
+ depends on SMP && PREEMPT
+
config RWSEM_XCHGADD_ALGORITHM
bool
default y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index ab9a264..f7237c5 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -235,6 +235,11 @@
# Define implied options from the CPU selection here
#
+config GENERIC_LOCKBREAK
+ bool
+ default y
+ depends on SMP && PREEMPT
+
config RWSEM_GENERIC_SPINLOCK
bool
depends on M32R
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 6b0f85f..4fad0a3 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -694,6 +694,11 @@
endmenu
+config GENERIC_LOCKBREAK
+ bool
+ default y
+ depends on SMP && PREEMPT
+
config RWSEM_GENERIC_SPINLOCK
bool
default y
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index b8ef178..2b649c4 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -19,6 +19,11 @@
config STACK_GROWSUP
def_bool y
+config GENERIC_LOCKBREAK
+ bool
+ default y
+ depends on SMP && PREEMPT
+
config RWSEM_GENERIC_SPINLOCK
def_bool y
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 232c298..c17a194 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -53,6 +53,11 @@
bool
default y
+config GENERIC_LOCKBREAK
+ bool
+ default y
+ depends on SMP && PREEMPT
+
config ARCH_HAS_ILOG2_U32
bool
default y
diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig
index 10b212a..1e25bce 100644
--- a/arch/sparc64/Kconfig
+++ b/arch/sparc64/Kconfig
@@ -200,6 +200,11 @@
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
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2393630..db434f8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -19,6 +19,10 @@
config X86
def_bool y
+config GENERIC_LOCKBREAK
+ def_bool y
+ depends on SMP && PREEMPT
+
config GENERIC_TIME
def_bool y