From 719323dcabc816535c77a109a9d8daac7f626c32 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Mon, 30 May 2011 20:27:57 +0300 Subject: [PATCH] kvm tools: Add debug mode to brlock Adds a debug mode which allows to switch the brlock into a big rwlock. This can be used to verify we don't end up with a BKL kind of lock with the current brlock implementation. Signed-off-by: Sasha Levin Signed-off-by: Pekka Enberg --- tools/kvm/include/kvm/brlock.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/tools/kvm/include/kvm/brlock.h b/tools/kvm/include/kvm/brlock.h index 2e2e0f80f3a1..bd1d882ac055 100644 --- a/tools/kvm/include/kvm/brlock.h +++ b/tools/kvm/include/kvm/brlock.h @@ -17,9 +17,25 @@ #define barrier() __asm__ __volatile__("": : :"memory") #endif +#ifdef KVM_BRLOCK_DEBUG + +#include "kvm/rwsem.h" + +DECLARE_RWSEM(brlock_sem); + +#define br_read_lock() down_read(&brlock_sem); +#define br_read_unlock() up_read(&brlock_sem); + +#define br_write_lock() down_write(&brlock_sem); +#define br_write_unlock() up_write(&brlock_sem); + +#else + #define br_read_lock() barrier() #define br_read_unlock() barrier() #define br_write_lock() kvm__pause() #define br_write_unlock() kvm__continue() #endif + +#endif -- 2.39.5