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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Pavel Emelyanov <xemul@parallels.com>
Cc: David Miller <davem@davemloft.net>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Linux Netdev List <netdev@vger.kernel.org>
Subject: Re: [PATCH 1/5] net: Don't use ifindices in hash fns
Date: Mon, 06 Aug 2012 13:51:57 +0200	[thread overview]
Message-ID: <1344253917.26674.13.camel@edumazet-glaptop> (raw)
In-Reply-To: <501FA3FA.9010107@parallels.com>

On Mon, 2012-08-06 at 15:01 +0400, Pavel Emelyanov wrote:

> Damn :( You're right.
> 
> > This returns 0 as is
> 
> Well, on 64-bit no, but what it does is also not what it was supposed to.
> 

Here, my L1_CACHE_BYTES is 64, but whatever

> > I would define a generic pointer hash mix instead of a 'net_device
> > thing'
> > 
> > static inline u32 ptr_hash_mix(void *ptr)
> > {
> > #if BITS_PER_LONG==32
> > 	return (u32)(unsigned long)ptr;
> > #else
> > 	return (u32)((unsigned long)ptr >> L1_CACHE_SHIFT);
> > #endif
> > }
> 
> OK. It will also obsolete the net_hash_mix then. Any suggestions where to put
> the new one?

Not obsolete net_hash_mix(), since this one can return 0 if
CONFIG_NET_NS is not set.

static inline unsigned int net_hash_mix(struct net *net)
{
#ifdef CONFIG_NET_NS
	return ptr_hash_mix(net);
#else
	return 0;
#endif
}

I dont know, you could add this to include/linux/hash.h

  reply	other threads:[~2012-08-06 11:52 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-06 10:30 [PATCH net-next 0/5] Per-net and on-demand link indices (and related) Pavel Emelyanov
2012-08-06 10:30 ` [PATCH 1/5] net: Don't use ifindices in hash fns Pavel Emelyanov
2012-08-06 10:43   ` Eric Dumazet
2012-08-06 11:01     ` Pavel Emelyanov
2012-08-06 11:51       ` Eric Dumazet [this message]
2012-08-06 10:31 ` [PATCH 2/5] net: Allow to create links with given ifindex Pavel Emelyanov
2012-08-06 10:31 ` [PATCH 3/5] veth: Allow to create peer link " Pavel Emelyanov
2012-08-06 10:31 ` [PATCH 4/5] net: Make ifindex generation per-net namespace Pavel Emelyanov
2012-08-06 10:32 ` [PATCH 5/5] net: Loopback ifindex is constant now Pavel Emelyanov
2012-08-06 11:54   ` Eric Dumazet
2012-08-06 12:13     ` Pavel Emelyanov

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