Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268589AbUILKLf (ORCPT ); Sun, 12 Sep 2004 06:11:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268591AbUILKLf (ORCPT ); Sun, 12 Sep 2004 06:11:35 -0400 Received: from natnoddy.rzone.de ([81.169.145.166]:13552 "EHLO natnoddy.rzone.de") by vger.kernel.org with ESMTP id S268589AbUILKLR (ORCPT ); Sun, 12 Sep 2004 06:11:17 -0400 From: Arnd Bergmann To: Zwane Mwaikambo Subject: Re: [PATCH] Yielding processor resources during lock contention Date: Sun, 12 Sep 2004 12:10:32 +0200 User-Agent: KMail/1.6.2 Cc: Linus Torvalds , Paul Mackerras , Linux Kernel , Andrew Morton , Anton Blanchard , "Nakajima, Jun" , Andi Kleen , Ingo Molnar , Martin Schwidefsky References: In-Reply-To: MIME-Version: 1.0 Message-Id: <200409121210.32259.arnd@arndb.de> Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg=pgp-sha1; boundary="Boundary-02=_YCCRBpvt/IsLG5P"; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1412 Lines: 43 --Boundary-02=_YCCRBpvt/IsLG5P Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Sonntag, 12. September 2004 06:59, Zwane Mwaikambo wrote: > The following patch introduces cpu_lock_yield which allows architectures= =20 > to possibly yield processor resources during lock contention. The origina= l=20 > requirement stems from Paul's requirement on PPC64 LPAR systems to yield= =20 > the processor to the hypervisor instead of spinning.=20 =46or s390, this was solved by simply defining cpu_relax() to the hypervisor yield operation, because we found that cpu_relax() is used only in busy-wait situations where it makes sense to continue on another virtual CPU. What is the benefit of not always doing a full hypervisor yield when you hit cpu_relax()? Arnd <>< --Boundary-02=_YCCRBpvt/IsLG5P Content-Type: application/pgp-signature Content-Description: signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQBBRCCY5t5GS2LDRf4RAmrLAKCVu/b5omHQlZ6lqkZfXagdySzIAwCglWEP guEo1FqkpG1bfMVizqjQtOQ= =dxuj -----END PGP SIGNATURE----- --Boundary-02=_YCCRBpvt/IsLG5P-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/