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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
parenta95d67f87e1a5f1b4429be3ba3bf7b4051657908 (diff)
downloadlinux-95c354fe9f7d6decc08a92aa26eb233ecc2155bf.tar.bz2
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')
-rw-r--r--arch/arm/Kconfig5
-rw-r--r--arch/ia64/Kconfig5
-rw-r--r--arch/m32r/Kconfig5
-rw-r--r--arch/mips/Kconfig5
-rw-r--r--arch/parisc/Kconfig5
-rw-r--r--arch/powerpc/Kconfig5
-rw-r--r--arch/sparc64/Kconfig5
-rw-r--r--arch/x86/Kconfig4
8 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index de211ac3853e..77201d3f7479 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -91,6 +91,11 @@ config GENERIC_IRQ_PROBE
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 bef47725d4ad..4a81b7fb191a 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -42,6 +42,11 @@ config MMU
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 ab9a264cb194..f7237c5f531e 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -235,6 +235,11 @@ config IRAM_SIZE
# 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 6b0f85f02c79..4fad0a34b997 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -694,6 +694,11 @@ source "arch/mips/vr41xx/Kconfig"
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 b8ef1787a191..2b649c46631c 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -19,6 +19,11 @@ config MMU
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 232c298c933f..c17a194beb0e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -53,6 +53,11 @@ config RWSEM_XCHGADD_ALGORITHM
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 10b212a1f9f5..1e25bce0366d 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
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 23936301db56..db434f8171d3 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