From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Christoph Lameter <cl@linux-foundation.org>,
Pekka Enberg <penberg@kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Matt Mackall <mpm@selenic.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org
Subject: [PATCH 4/4] net,rcu: don't assume the size of struct rcu_head
Date: Tue, 01 Mar 2011 16:03:44 +0800 [thread overview]
Message-ID: <4D6CA860.3020409@cn.fujitsu.com> (raw)
struct dst_entry assumes the size of struct rcu_head as 2 * sizeof(long)
and manually adds pads for aligning for "__refcnt".
When the size of struct rcu_head is changed, these manual padding
is wrong. Use __attribute__((aligned (64))) instead.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
diff --git a/include/net/dst.h b/include/net/dst.h
index 93b0310..4ef6c4a 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -62,8 +62,6 @@ struct dst_entry {
struct hh_cache *hh;
#ifdef CONFIG_XFRM
struct xfrm_state *xfrm;
-#else
- void *__pad1;
#endif
int (*input)(struct sk_buff*);
int (*output)(struct sk_buff*);
@@ -74,23 +72,18 @@ struct dst_entry {
#ifdef CONFIG_NET_CLS_ROUTE
__u32 tclassid;
-#else
- __u32 __pad2;
#endif
/*
* Align __refcnt to a 64 bytes alignment
* (L1_CACHE_SIZE would be too much)
- */
-#ifdef CONFIG_64BIT
- long __pad_to_align_refcnt[1];
-#endif
- /*
+ *
* __refcnt wants to be on a different cache line from
* input/output/ops or performance tanks badly
*/
- atomic_t __refcnt; /* client references */
+ atomic_t __refcnt /* client references */
+ __attribute__((aligned (64)));
int __use;
unsigned long lastuse;
union {
--
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next reply other threads:[~2011-03-01 8:02 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-01 8:03 Lai Jiangshan [this message]
2011-03-01 8:16 ` [PATCH 4/4] net,rcu: don't assume the size of struct rcu_head David Miller
2011-03-01 8:20 ` Eric Dumazet
2011-03-01 8:53 ` [PATCH 4/4 V2] " Lai Jiangshan
2011-03-01 9:20 ` Eric Dumazet
2011-03-02 2:46 ` Lai Jiangshan
2011-03-02 3:02 ` Eric Dumazet
2011-03-01 8:20 ` [PATCH 4/4] " Eric Dumazet
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