From: Pavel Emelyanov <xemul@parallels•com>
To: David Miller <davem@davemloft•net>,
Eric Dumazet <eric.dumazet@gmail•com>,
"Eric W. Biederman" <ebiederm@xmission•com>,
Linux Netdev List <netdev@vger•kernel.org>
Subject: [PATCH 1/6] hash: Introduce ptr_hash_mix routine
Date: Mon, 06 Aug 2012 18:13:47 +0400 [thread overview]
Message-ID: <501FD11B.6000006@parallels.com> (raw)
In-Reply-To: <501FD0F2.4040609@parallels.com>
This one is used to make a salt out of a pointer to be mixed to some
hash function later. Idea and implementation are proposed by Eric Dumazet.
Signed-off-by: Pavel Emelyanov <xemul@parallels•com>
---
include/linux/hash.h | 10 ++++++++++
include/net/netns/hash.h | 9 ++-------
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/include/linux/hash.h b/include/linux/hash.h
index b80506b..1bd0ab1 100644
--- a/include/linux/hash.h
+++ b/include/linux/hash.h
@@ -14,6 +14,7 @@
* machines where multiplications are slow.
*/
+#include <linux/cache.h>
#include <asm/types.h>
/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */
@@ -67,4 +68,13 @@ static inline unsigned long hash_ptr(const void *ptr, unsigned int bits)
{
return hash_long((unsigned long)ptr, bits);
}
+
+static inline u32 ptr_hash_mix(const void *ptr)
+{
+#if BITS_PER_LONG == 32
+ return (u32)(unsigned long)ptr;
+#else
+ return (u32)((unsigned long)ptr >> L1_CACHE_SHIFT);
+#endif
+}
#endif /* _LINUX_HASH_H */
diff --git a/include/net/netns/hash.h b/include/net/netns/hash.h
index c06ac58..bcdabe0 100644
--- a/include/net/netns/hash.h
+++ b/include/net/netns/hash.h
@@ -1,19 +1,14 @@
#ifndef __NET_NS_HASH_H__
#define __NET_NS_HASH_H__
-#include <asm/cache.h>
+#include <linux/hash.h>
struct net;
static inline unsigned int net_hash_mix(struct net *net)
{
#ifdef CONFIG_NET_NS
- /*
- * shift this right to eliminate bits, that are
- * always zeroed
- */
-
- return (unsigned)(((unsigned long)net) >> L1_CACHE_SHIFT);
+ return ptr_hash_mix(net);
#else
return 0;
#endif
--
1.7.6.5
next prev parent reply other threads:[~2012-08-06 14:13 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-06 14:13 [PATCH net-next 0/6] Per-net and on-demand link indices (and related) v2 Pavel Emelyanov
2012-08-06 14:13 ` Pavel Emelyanov [this message]
2012-08-06 20:44 ` [PATCH 1/6] hash: Introduce ptr_hash_mix routine David Miller
2012-08-07 9:11 ` Pavel Emelyanov
2012-08-07 9:28 ` Eric Dumazet
2012-08-07 9:55 ` Pavel Emelyanov
2012-08-07 10:30 ` Eric Dumazet
2012-08-07 21:39 ` David Miller
2012-08-06 14:14 ` [PATCH 2/6] net: Dont use ifindices in hash fns Pavel Emelyanov
2012-08-06 14:14 ` [PATCH 3/6] net: Allow to create links with given ifindex Pavel Emelyanov
2012-08-07 11:01 ` [PATCH 2/5 (resend)] " Pavel Emelyanov
2012-08-07 13:14 ` Eric Dumazet
2012-08-07 21:42 ` David Miller
2012-08-06 14:14 ` [PATCH 4/6] veth: Allow to create peer link " Pavel Emelyanov
2012-08-07 11:02 ` [PATCH 3/5 (resend)] " Pavel Emelyanov
2012-08-07 13:14 ` Eric Dumazet
2012-08-07 18:36 ` Ben Hutchings
2012-08-08 9:00 ` Pavel Emelyanov
2012-08-08 13:25 ` Ben Hutchings
2012-08-08 13:38 ` Pavel Emelyanov
2012-08-06 14:14 ` [PATCH 5/6] net: Make ifindex generation per-net namespace Pavel Emelyanov
2012-08-07 11:02 ` [PATCH 4/5 (resend)] " Pavel Emelyanov
2012-08-07 12:11 ` Eric Dumazet
2012-08-07 12:37 ` [PATCH 4/5 (resend)] net: Make ifindex generation per-net namespace (v2) Pavel Emelyanov
2012-08-07 13:13 ` Eric Dumazet
2012-08-06 14:15 ` [PATCH 6/6] net: Loopback ifindex is constant now Pavel Emelyanov
2012-08-07 11:02 ` [PATCH 5/5 (resend)] " Pavel Emelyanov
2012-08-07 13:13 ` Eric Dumazet
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