From mboxrd@z Thu Jan 1 00:00:00 1970 From: "John W. Linville" Subject: Re: [PATCH/RFC v2] introduce ARCH_CAN_UNALIGNED_ACCESS Kconfig symbol Date: Thu, 20 Mar 2008 18:03:48 -0400 Message-ID: <20080320220348.GC1330@tuxdriver.com> References: <1206023695.16475.137.camel@johannes.berg> <20080320181310.GA17884@uranus.ravnborg.org> <1206038373.16475.150.camel@johannes.berg> <20080320.141307.173590705.davem@davemloft.net> <1206048106.16475.161.camel@johannes.berg> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , sam-uyr5N9Q2VtJg9hUCZPvPmw@public.gmane.org, dsd-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-wireless-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Johannes Berg Return-path: Content-Disposition: inline In-Reply-To: <1206048106.16475.161.camel-YfaajirXv214zXjbi5bjpg@public.gmane.org> Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org On Thu, Mar 20, 2008 at 10:21:46PM +0100, Johannes Berg wrote: > > > I think you're semantically testing the wrong thing. > > > > It's not if unaligned accesses are supported, it's if they are > > efficient enough or not. > > > > For example, sparc64 fully handles unaligned accesses but taking the > > trap to fix it up is slow. So sparc64 "can" handle unaligned > > accesses, but whether we want to set this symbol or not is another > > matter. > > Yeah, good point. Should I rename it to HAVE_EFFICIENT_UNALIGNED_ACCESS > or similar? Or have it defined as some sort of number so you can make > actually make tradeoffs? Like Dave Woodhouse suggested at some point to > have get_unaligned() take an argument that indicates the probability... Ugh...that sounds like premature optimization to me... While I think Dave has a point, I don't think you should labor the word choice too much. Try to document it as clearly as possible and hope for the best -- I hear that the arch maintainers are top notch! :-) John -- John W. Linville linville-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html