From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033031AbbKEIFD (ORCPT ); Thu, 5 Nov 2015 03:05:03 -0500 Received: from www.linutronix.de ([62.245.132.108]:53390 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030915AbbKEIFB (ORCPT ); Thu, 5 Nov 2015 03:05:01 -0500 Date: Thu, 5 Nov 2015 09:04:14 +0100 (CET) From: Thomas Gleixner To: Linus Torvalds cc: Ingo Molnar , LKML , Peter Anvin , Borislav Petkov , Peter Zijlstra , Mike Travis , Daniel J Blueman Subject: Re: [patch 02/14] x86/apic: Implement single target IPI function for x2apic_cluster In-Reply-To: Message-ID: References: <20151104215716.810356093@linutronix.de> <20151104220848.817975597@linutronix.de> <20151105063813.GA12730@gmail.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Nov 2015, Linus Torvalds wrote: > On Wed, Nov 4, 2015 at 10:38 PM, Ingo Molnar wrote: > > > > but in the above sequence I think we can do even better: we don't need the > > local_irq_save()/restore() I think. > > Right. Thomas added that one to my patch. > > I don't think he realized just *how* trivial sending a single IPI is > with the x2apic, and just how horribly nasty the mask case is in > comparison (and how nasty it is that we historically turn a the single > ipi into a mask). Yeah, I was too tired to look at the details. Will fix that up for the other trivial cases as well. Thanks, tglx