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authorJosh Triplett <josh@joshtriplett.org>2014-04-07 15:39:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-07 16:36:14 -0700
commit64b47e8fdb40a0d46e8cf458dd3e24f8afa073f6 (patch)
tree284e2335ba622406f3d3437c2abd416cc8979294 /kernel
parent188a81409ff7de1c5aae947a96356ddd8ff4aaa3 (diff)
downloadlinux-64b47e8fdb40a0d46e8cf458dd3e24f8afa073f6.tar.gz
linux-64b47e8fdb40a0d46e8cf458dd3e24f8afa073f6.tar.xz
lglock: map to spinlock when !CONFIG_SMP
When the system has only one CPU, lglock is effectively a spinlock; map it directly to spinlock to eliminate the indirection and duplicate code. In addition to removing overhead, this drops 1.6k of code with a defconfig modified to have !CONFIG_SMP, and 1.1k with a minimal config. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michal Marek <mmarek@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Howells <dhowells@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/locking/Makefile3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index 306a76b..b8bdcd4 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -1,5 +1,5 @@
-obj-y += mutex.o semaphore.o rwsem.o lglock.o mcs_spinlock.o
+obj-y += mutex.o semaphore.o rwsem.o mcs_spinlock.o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_lockdep.o = -pg
@@ -14,6 +14,7 @@ ifeq ($(CONFIG_PROC_FS),y)
obj-$(CONFIG_LOCKDEP) += lockdep_proc.o
endif
obj-$(CONFIG_SMP) += spinlock.o
+obj-$(CONFIG_SMP) += lglock.o
obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o