[PATCH 08/10] ARC: [plat-eznps] spinlock aware for MTM

Noam Camus
2017-05-25T02:35:25Z

From: Noam Camus <noamca@mellanox.com>

This way when we execute "ex" during trying to hold lock we can switch to
other HW thread and utilize the core intead of just spinning on a lock.

We noticed about 10% improvement of execution time with hackbench test.

Signed-off-by: Noam Camus <noamca@mellanox.com>
---
arch/arc/include/asm/spinlock.h | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h
index 233d5ff..0a54ce7 100644
--- a/arch/arc/include/asm/spinlock.h
+++ b/arch/arc/include/asm/spinlock.h
@@ -252,9 +252,15 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)

__asm__ __volatile__(
"1: ex %0, [%1] \n"
+#ifdef CONFIG_EZNPS_MTM_EXT
+ " .word %3 \n"
+#endif
" breq %0, %2, 1b \n"
: "+&r" (val)
: "r"(&(lock->slock)), "ir"(__ARCH_SPIN_LOCK_LOCKED__)
+#ifdef CONFIG_EZNPS_MTM_EXT
+ , "i"(CTOP_INST_SCHD_RW)
+#endif
: "memory");

/*
--
1.7.1