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| author | Nick Piggin <npiggin@suse.de> | 2008-01-30 13:31:20 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:31:20 +0100 |
| commit | 95c354fe9f7d6decc08a92aa26eb233ecc2155bf (patch) | |
| tree | ec9267032ea875e84216cfb20acb2cfc7c62149f /arch/arm/Kconfig | |
| parent | a95d67f87e1a5f1b4429be3ba3bf7b4051657908 (diff) | |
| download | lwn-95c354fe9f7d6decc08a92aa26eb233ecc2155bf.tar.gz lwn-95c354fe9f7d6decc08a92aa26eb233ecc2155bf.zip | |
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/arm/Kconfig')
| -rw-r--r-- | arch/arm/Kconfig | 5 |
1 files changed, 5 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 |