From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: lkml <linux-kernel@vger.kernel.org>, <arc-linux-dev@synopsys.com>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [PATCH 1/6] Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock"
Date: Mon, 3 Aug 2015 15:33:03 +0530 [thread overview]
Message-ID: <1438596188-10875-2-git-send-email-vgupta@synopsys.com> (raw)
In-Reply-To: <1438596188-10875-1-git-send-email-vgupta@synopsys.com>
Extended testing of quad core configuration revealed that this fix was
insufficient. Specifically LTP open posix shm_op/23-1 would cause the
hardware livelock in llock/scond loop in update_cpu_load_active()
So remove this and make way for a proper workaround
This reverts commit a5c8b52abe677977883655166796f167ef1e0084.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/include/asm/atomic.h | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h
index 03484cb4d16d..20b7dc17979e 100644
--- a/arch/arc/include/asm/atomic.h
+++ b/arch/arc/include/asm/atomic.h
@@ -23,21 +23,13 @@
#define atomic_set(v, i) (((v)->counter) = (i))
-#ifdef CONFIG_ISA_ARCV2
-#define PREFETCHW " prefetchw [%1] \n"
-#else
-#define PREFETCHW
-#endif
-
#define ATOMIC_OP(op, c_op, asm_op) \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
unsigned int temp; \
\
__asm__ __volatile__( \
- "1: \n" \
- PREFETCHW \
- " llock %0, [%1] \n" \
+ "1: llock %0, [%1] \n" \
" " #asm_op " %0, %0, %2 \n" \
" scond %0, [%1] \n" \
" bnz 1b \n" \
@@ -58,9 +50,7 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \
smp_mb(); \
\
__asm__ __volatile__( \
- "1: \n" \
- PREFETCHW \
- " llock %0, [%1] \n" \
+ "1: llock %0, [%1] \n" \
" " #asm_op " %0, %0, %2 \n" \
" scond %0, [%1] \n" \
" bnz 1b \n" \
--
1.9.1
next prev parent reply other threads:[~2015-08-03 10:03 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-03 10:03 [PATCH 0/6] ARC: spinlocks/atomics rework Vineet Gupta
2015-08-03 10:03 ` Vineet Gupta [this message]
2015-08-03 10:03 ` [PATCH 2/6] ARC: refactor atomic inline asm operands with symbolic names Vineet Gupta
2015-08-03 10:03 ` [PATCH 3/6] ARC: LLOCK/SCOND based spin_lock Vineet Gupta
2015-08-03 11:29 ` Peter Zijlstra
2015-08-03 11:44 ` Vineet Gupta
2015-08-03 10:03 ` [PATCH 4/6] ARC: LLOCK/SCOND based rwlock Vineet Gupta
2015-08-03 11:33 ` Peter Zijlstra
2015-08-03 11:51 ` Vineet Gupta
2015-08-03 10:03 ` [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Vineet Gupta
2015-08-03 11:41 ` Peter Zijlstra
2015-08-03 13:01 ` Vineet Gupta
2015-08-03 13:50 ` Vineet Gupta
2015-08-03 14:08 ` Peter Zijlstra
2015-08-03 11:50 ` Peter Zijlstra
2015-08-03 13:02 ` Vineet Gupta
2015-08-03 13:06 ` Peter Zijlstra
2015-08-03 10:03 ` [PATCH 6/6] ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle Vineet Gupta
2015-08-03 11:43 ` Peter Zijlstra
2015-08-03 14:40 ` Vineet Gupta
2015-08-03 14:42 ` Peter Zijlstra
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