Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759777Ab2JLP3h (ORCPT ); Fri, 12 Oct 2012 11:29:37 -0400 Received: from mga14.intel.com ([143.182.124.37]:54029 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759736Ab2JLP3g (ORCPT ); Fri, 12 Oct 2012 11:29:36 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,576,1344236400"; d="scan'208";a="203769481" From: "Liu, Chuansheng" To: anish kumar CC: Thomas Gleixner , "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: AQHNqI3GXuKKKGSRjESsjhgprhwMOJe1yz5A Date: Fri, 12 Oct 2012 15:29:31 +0000 Message-ID: <27240C0AC20F114CBF8149A2696CBE4A195A8D@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> <27240C0AC20F114CBF8149A2696CBE4A195A6B@SHSMSX101.ccr.corp.intel.com> <1350055478.8329.24.camel@anish-Inspiron-N5050> In-Reply-To: <1350055478.8329.24.camel@anish-Inspiron-N5050> 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="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id q9CFTeOA016306 Content-Length: 1938 Lines: 38 > -----Original Message----- > From: anish kumar [mailto:anish198519851985@gmail.com] > Sent: Friday, October 12, 2012 11:25 PM > To: Liu, Chuansheng > Cc: Thomas Gleixner; linux-kernel@vger.kernel.org > Subject: RE: [PATCH] genirq: for edge interrupt IRQS_ONESHOT support with irq > thread > > On Fri, 2012-10-12 at 14:57 +0000, Liu, Chuansheng wrote: > > > 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? > Why will the interrupt be raised again?Is not it masked?I read tglx I means because it is masked, if at this time device issues edge irq, It will not be delivered and lost. > statement as this:if the interrupt is being handled on one core, then > the delivery of new interrupt can be on the second core and in that case > it will see IRQ_INPROGRESS flag and it will *mask* it and set the flag > as pending.So there is no chance of any new interrupt. > > 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/ > ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?