linux-kernel - [PATCH] debug_core: cleanup kgdb_cpu_enter() that removing smp

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Date:	Fri, 26 Nov 2010 17:14:58 +0800
From:	Dongdong Deng <libfetion@...il.com>
To:	jason.wessel@...driver.com
Cc:	kgdb-bugreport@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
	libfetion@...il.com
Subject: [PATCH] debug_core: cleanup kgdb_cpu_enter() that removing smp_mb()

Commit dfee3a7b92208b30f77876068aece9ea571270c2(debug_core:
refactor locking for master/slave cpus) uses spin_lock to replace
the atomic counter lock mechanism, and most kgdb data was designed
to per-cpu, thus the 'smp_mb()' operation is useless here now.

Signed-off-by: Dongdong Deng <libfetion@...il.com>
---
 kernel/debug/debug_core.c |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 722968f..1b019b5 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -492,9 +492,6 @@ acquirelock:
 	kgdb_info[cpu].ret_state = 0;
 	kgdb_info[cpu].irq_depth = hardirq_count() >> HARDIRQ_SHIFT;
 
-	/* Make sure the above info reaches the primary CPU */
-	smp_mb();
-
 	if (exception_level == 1) {
 		if (raw_spin_trylock(&dbg_master_lock))
 			atomic_xchg(&kgdb_active, cpu);
-- 
1.6.0.4

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