Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759640Ab2JLO5i (ORCPT ); Fri, 12 Oct 2012 10:57:38 -0400 Received: from mga14.intel.com ([143.182.124.37]:39079 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759125Ab2JLO5h convert rfc822-to-8bit (ORCPT ); Fri, 12 Oct 2012 10:57:37 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,576,1344236400"; d="scan'208";a="203757259" From: "Liu, Chuansheng" To: Thomas Gleixner CC: "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] genirq: for edge interrupt IRQS_ONESHOT support with irq thread Thread-Topic: [PATCH] genirq: for edge interrupt IRQS_ONESHOT support with irq thread Thread-Index: AQHNqIA0xNWms64G/kSGCSQSXS8Oype1wbNA Date: Fri, 12 Oct 2012 14:57:26 +0000 Message-ID: <27240C0AC20F114CBF8149A2696CBE4A195A6B@SHSMSX101.ccr.corp.intel.com> References: <1350045084.13178.19.camel@cliu38-desktop-build> <27240C0AC20F114CBF8149A2696CBE4A19587A@SHSMSX101.ccr.corp.intel.com> <27240C0AC20F114CBF8149A2696CBE4A1958B9@SHSMSX101.ccr.corp.intel.com> In-Reply-To: Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 903 Lines: 15 > On SMP an interrupt which is raised after the ack() again before the > handler finishes, can invoke another delivery on a different CPU, > which then sees the IRQ_INPROGESS flag, masks it and flags it > PENDING. When the primary handler on the first CPU returns, it sees > the PENDING flag, unmasks and invokes the handler another time. In this case, when IRQ_INPROGRESS flag is set, on another CPU, it will mask and ack it, if before the primary handler on the first CPU returns, the edge interrupt is raised again, it will be lost, right? So I think set PENDING just confirm one time, it just depends on primary handler execution time and irq frequency. -- 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/