From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753776AbZGVV3p (ORCPT ); Wed, 22 Jul 2009 17:29:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753085AbZGVV3o (ORCPT ); Wed, 22 Jul 2009 17:29:44 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:56516 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752908AbZGVV3n (ORCPT ); Wed, 22 Jul 2009 17:29:43 -0400 To: Jeremy Fitzhardinge Cc: "linux-kernel\@vger.kernel.org" , "mingo\@redhat.com" , "hpa\@zytor.com" , "tglx\@linutronix.de" , Jeremy Fitzhardinge , Yinghai Lu References: <4A676E89.9010606@goop.org> From: ebiederm@xmission.com (Eric W. Biederman) Date: Wed, 22 Jul 2009 14:29:33 -0700 In-Reply-To: <4A676E89.9010606@goop.org> (Jeremy Fitzhardinge's message of "Wed\, 22 Jul 2009 12\:54\:49 -0700") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Rcpt-To: jeremy@goop.org, yinghai@kernel.org, Jeremy.Fitzhardinge@citrix.com, tglx@linutronix.de, hpa@zytor.com, mingo@redhat.com, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: *****;Jeremy Fitzhardinge X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 TR_Symld_Words too many words that have symbols inside * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_04 7+ unique symbols in subject * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_03 6+ unique symbols in subject * 8.0 XMSpecificSbj Contains a known spam subject * 0.0 XM_SPF_Neutral SPF-Neutral * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay Subject: Re: [tip:x86/apic] x86/ioapic.c: unify ioapic_retrigger_irq() X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jeremy Fitzhardinge writes: > On 07/18/09 05:05, tip-bot for Jeremy Fitzhardinge wrote: >> Commit-ID: e25371d60cb06a44d7a32d7966ab9bfbeacb9390 >> Gitweb: http://git.kernel.org/tip/e25371d60cb06a44d7a32d7966ab9bfbeacb9390 >> Author: Jeremy Fitzhardinge >> AuthorDate: Mon, 8 Jun 2009 03:49:01 -0700 >> Committer: Jeremy Fitzhardinge >> CommitDate: Tue, 14 Jul 2009 13:32:51 -0700 >> >> x86/ioapic.c: unify ioapic_retrigger_irq() >> >> The 32 and 64-bit versions of ioapic_retrigger_irq() are identical >> except the 64-bit one takes vector_lock. vector_lock is defined and >> used on 32-bit too, so just use a common ioapic_retrigger_irq(). >> > > Having another look at this patch, the other difference is that the > 32-bit version just does: > > apic->send_IPI_self(irq_cfg(irq)->vector); > > whereas the 64-bit does: > > apic->send_IPI_mask(cpumask_of(cpumask_first(cfg->domain)), > cfg->vector); > > > Does 32-bit do the whole vector domain thing now? Are these actually > equivalent? Sending to self seems like it should be more efficient. It should. I believe YH did that work when he merged the x86_64 and i386 versions io_apic.c. Sending to self is a problem if we retrigger this from the wrong irq. Eric