Subject: Re: [PATCH] list.h: add list_for_each_struct_entry macro
From: Ben Hutchings <bhutchings@solarflare.com>
To: Jiri Pirko <jpirko@redhat.com>
Cc: linux-kernel@vger.kernel.org, davem@davemloft.net, netdev@vger.kernel.org
In-Reply-To: <20100118210718.GC4521@psychotron.redhat.com>
References: <20100118162338.GD4229@psychotron.lab.eng.brq.redhat.com>
	 <1263835033.3667.23.camel@achroite.uk.solarflarecom.com>
	 <20100118210718.GC4521@psychotron.redhat.com>
Content-Type: text/plain
Organization: Solarflare Communications
Date: Mon, 18 Jan 2010 21:14:18 +0000
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On Mon, 2010-01-18 at 22:07 +0100, Jiri Pirko wrote:
> Mon, Jan 18, 2010 at 06:17:13PM CET, bhutchings@solarflare.com wrote:
[...]
> >#define list_for_each_struct_entry(pos, head, type, posmember, member)	     \
> >	for (pos = list_empty(head) ? NULL :				     \
> >		&list_first_entry(head, type, member)->posmember;	     \
> >	     prefetch(container_of(pos, type, posmember)->member.next), pos; \
> >	     pos = list_is_last(&container_of(pos, type, posmember)->member, \
> >				head) ?	NULL :				     \
> >		&list_entry(container_of(pos, type, posmember)->member.next, \
> >			    type, member)->posmember)
> >
> 
> At the first glance, this would take even more cputime for lists longer
> than 2 or so, wouldn't it?

If you're concerned about speed, measure it, don't guess.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

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