From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 14 Sep 2004 13:13:29 +0200 From: Arjan van de Ven Subject: Re: [PATCH] shrink per_cpu_pages to fit 32byte cacheline Message-ID: <20040914111329.GB21362@devserv.devel.redhat.com> References: <20040913233835.GA23894@logos.cnet> <1095142204.2698.12.camel@laptop.fenrus.com> <20040914093407.GA23935@logos.cnet> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="GRPZ8SYKNexpdSJ7" Content-Disposition: inline In-Reply-To: <20040914093407.GA23935@logos.cnet> Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: akpm@osdl.org, "Martin J. Bligh" , linux-mm@kvack.org List-ID: --GRPZ8SYKNexpdSJ7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Sep 14, 2004 at 06:34:07AM -0300, Marcelo Tosatti wrote: > How come short access can cost 1 extra cycle? Because you need two "read bytes" ? on an x86, a word (2byte) access will cause a prefix byte to the instruction, that particular prefix byte will take an extra cycle during execution of the instruction and potentially reduces the parallal decodability of instructions.... --GRPZ8SYKNexpdSJ7 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFBRtJZxULwo51rQBIRAlf6AJ9gWfR/xjSybRxBBOW/Gx/Hj284LACeK49m gqxhGFAiEUkWeOEYBEjP6ik= =BcWc -----END PGP SIGNATURE----- --GRPZ8SYKNexpdSJ7-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org