From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753177AbbKIKML (ORCPT ); Mon, 9 Nov 2015 05:12:11 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:33687 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752736AbbKIKHT (ORCPT ); Mon, 9 Nov 2015 05:07:19 -0500 Subject: Re: [PATCH 07/14] genirq: Add a new generic IPI reservation code to irq core To: Thomas Gleixner References: <1446549181-31788-1-git-send-email-qais.yousef@imgtec.com> <1446549181-31788-8-git-send-email-qais.yousef@imgtec.com> CC: , , , , , From: Qais Yousef Message-ID: <56407055.6080602@imgtec.com> Date: Mon, 9 Nov 2015 10:07:17 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.154.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/07/2015 01:31 PM, Thomas Gleixner wrote: > On Tue, 3 Nov 2015, Qais Yousef wrote: >> + >> + /* always allocate a virq per cpu */ >> + nr_irqs = ipi_mask_weight(dest); > That's not really a good assumption. Not all architectures need > seperate interrupt numbers / descriptors because they can allocate > from a per cpu interrupt space. We really want to handle that here as > well. So we need a flag in the IPI domain which tells us whether that > allocation needs to be weight(desc) or 1. OK. But is it bad to always allocate the weight? I thought allocating virqs is cheap, or maybe not? Thanks, Qais From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailapp01.imgtec.com ([195.59.15.196]:15594 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27013038AbbKIKHXn-5zP (ORCPT ); Mon, 9 Nov 2015 11:07:23 +0100 Subject: Re: [PATCH 07/14] genirq: Add a new generic IPI reservation code to irq core References: <1446549181-31788-1-git-send-email-qais.yousef@imgtec.com> <1446549181-31788-8-git-send-email-qais.yousef@imgtec.com> From: Qais Yousef Message-ID: <56407055.6080602@imgtec.com> Date: Mon, 9 Nov 2015 10:07:17 +0000 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-Path: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: Thomas Gleixner Cc: linux-kernel@vger.kernel.org, jason@lakedaemon.net, marc.zyngier@arm.com, jiang.liu@linux.intel.com, ralf@linux-mips.org, linux-mips@linux-mips.org Message-ID: <20151109100717.kPS6TLOv49GEXwUjz_2wDUcTQ8PAjVAQdyrMn3HVxGg@z> On 11/07/2015 01:31 PM, Thomas Gleixner wrote: > On Tue, 3 Nov 2015, Qais Yousef wrote: >> + >> + /* always allocate a virq per cpu */ >> + nr_irqs = ipi_mask_weight(dest); > That's not really a good assumption. Not all architectures need > seperate interrupt numbers / descriptors because they can allocate > from a per cpu interrupt space. We really want to handle that here as > well. So we need a flag in the IPI domain which tells us whether that > allocation needs to be weight(desc) or 1. OK. But is it bad to always allocate the weight? I thought allocating virqs is cheap, or maybe not? Thanks, Qais