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| author | Jiri Benc <jbenc@redhat.com> | 2015-08-21 12:41:14 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-08-23 16:51:17 -0700 |
| commit | 751a587ac9f9a8bf314590fbac32d9e418060c5a (patch) | |
| tree | 9ddb90651ebd72777150a6af48f22f7f088b71fb /include/net/dst.h | |
| parent | 31fbde9967330404175a06df15bdb24d671d4475 (diff) | |
| download | lwn-751a587ac9f9a8bf314590fbac32d9e418060c5a.tar.gz lwn-751a587ac9f9a8bf314590fbac32d9e418060c5a.zip | |
route: fix breakage after moving lwtunnel state
__recnt and related fields need to be in its own cacheline for performance
reasons. Commit 61adedf3e3f1 ("route: move lwtunnel state to dst_entry")
broke that on 32bit archs, causing BUILD_BUG_ON in dst_hold to be triggered.
This patch fixes the breakage by moving the lwtunnel state to the end of
dst_entry on 32bit archs. Unfortunately, this makes it share the cacheline
with __refcnt and may affect performance, thus further patches may be
needed.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/dst.h')
| -rw-r--r-- | include/net/dst.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index 0a9a723f6c19..ef8f1d43a203 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -44,7 +44,6 @@ struct dst_entry { #else void *__pad1; #endif - struct lwtunnel_state *lwtstate; int (*input)(struct sk_buff *); int (*output)(struct sock *sk, struct sk_buff *skb); @@ -85,11 +84,12 @@ struct dst_entry { __u32 __pad2; #endif +#ifdef CONFIG_64BIT + struct lwtunnel_state *lwtstate; /* * Align __refcnt to a 64 bytes alignment * (L1_CACHE_SIZE would be too much) */ -#ifdef CONFIG_64BIT long __pad_to_align_refcnt[1]; #endif /* @@ -99,6 +99,9 @@ struct dst_entry { atomic_t __refcnt; /* client references */ int __use; unsigned long lastuse; +#ifndef CONFIG_64BIT + struct lwtunnel_state *lwtstate; +#endif union { struct dst_entry *next; struct rtable __rcu *rt_next; |