Date: Tue, 14 Oct 2008 14:46:53 -0600 From: Scott Long <scottl@samsco.org> To: Marius Strobl <marius@FreeBSD.org> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r183896 - head/sys/dev/bge Message-ID: <48F5053D.7070705@samsco.org> In-Reply-To: <200810142028.m9EKShoL015514@svn.freebsd.org> References: <200810142028.m9EKShoL015514@svn.freebsd.org>
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Marius Strobl wrote: > Author: marius > Date: Tue Oct 14 20:28:42 2008 > New Revision: 183896 > URL: http://svn.freebsd.org/changeset/base/183896 > > Log: > Use bus_{read,write}_4(9) instead of bus_space_{read,write}_4(9) > in order to get rid of the bus space handle and tag in the softc. > Has anyone looked at the generated code from this interface switch and compared it what was getting generated previously? Way back when, including <machine/bus_memio.h> made bus_space_read|write_4() compile into a direct memory access on machines that supported it. The dubious removal of bus_memio.h and bus_pio.h took away that benefit, and I'm afraid that it's only getting worse now. Bus writes to card memory are still very important to high-performance devices and shouldn't be pessimized in the name of simpler-looking C code. Scott
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