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

Noam Camus noamca at mellanox.com
Wed May 24 19:34:18 PDT 2017


From: Noam Camus <noamca at 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 at 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




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