From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756652Ab1IGSoD (ORCPT ); Wed, 7 Sep 2011 14:44:03 -0400 Received: from www.linutronix.de ([62.245.132.108]:40737 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751052Ab1IGSoA (ORCPT ); Wed, 7 Sep 2011 14:44:00 -0400 Date: Wed, 7 Sep 2011 20:43:56 +0200 (CEST) From: Thomas Gleixner To: David Miller cc: yong.zhang0@gmail.com, linux-kernel@vger.kernel.org, mingo@elte.hu, joe@perches.com, sparclinux@vger.kernel.org Subject: Re: [PATCH 20/62] sparc: irq: Remove IRQF_DISABLED In-Reply-To: <20110907.141424.1469075127690660949.davem@davemloft.net> Message-ID: References: <20110907.135110.2069876782156753239.davem@davemloft.net> <20110907.141424.1469075127690660949.davem@davemloft.net> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) 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, 7 Sep 2011, David Miller wrote: > From: Thomas Gleixner > Date: Wed, 7 Sep 2011 19:57:21 +0200 (CEST) > > > On Wed, 7 Sep 2011, David Miller wrote: > >> From: Thomas Gleixner > >> Date: Wed, 7 Sep 2011 19:33:52 +0200 (CEST) > >> > >> We had big problems when openning thousands of virtual network > >> devices, each with their own unique IRQ, and pointed all at the same > >> cpu, and we'd get IRQ stack overflows. > >> > >> See commit c58543c869606532c2382f027d6466f4672ea756 > >> > >> So this change to make IRQF_DISABLED a nop has reintroduced this bug. > > > > See commit e58aa3d2d0cc01ad8d6f7f640a0670433f794922 > > > > We run ALL interrupt handlers with interrupts disabled for that reason > > and we even check and yell when an interrupt handler returns with > > interrupts enabled. That's why IRQF_DISABLED became meaningless. > > Awesome. > > Can I politely ask that a reference to that commit and something like > your paragraph here explaining things is added to these IRQF_DISABLED > removal patches? That's a good idea. I'll let sed loose on the changelogs when I pick them up. Thanks, tglx From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Date: Wed, 07 Sep 2011 18:43:56 +0000 Subject: Re: [PATCH 20/62] sparc: irq: Remove IRQF_DISABLED Message-Id: List-Id: References: <20110907.135110.2069876782156753239.davem@davemloft.net> <20110907.141424.1469075127690660949.davem@davemloft.net> In-Reply-To: <20110907.141424.1469075127690660949.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Miller Cc: yong.zhang0@gmail.com, linux-kernel@vger.kernel.org, mingo@elte.hu, joe@perches.com, sparclinux@vger.kernel.org On Wed, 7 Sep 2011, David Miller wrote: > From: Thomas Gleixner > Date: Wed, 7 Sep 2011 19:57:21 +0200 (CEST) > > > On Wed, 7 Sep 2011, David Miller wrote: > >> From: Thomas Gleixner > >> Date: Wed, 7 Sep 2011 19:33:52 +0200 (CEST) > >> > >> We had big problems when openning thousands of virtual network > >> devices, each with their own unique IRQ, and pointed all at the same > >> cpu, and we'd get IRQ stack overflows. > >> > >> See commit c58543c869606532c2382f027d6466f4672ea756 > >> > >> So this change to make IRQF_DISABLED a nop has reintroduced this bug. > > > > See commit e58aa3d2d0cc01ad8d6f7f640a0670433f794922 > > > > We run ALL interrupt handlers with interrupts disabled for that reason > > and we even check and yell when an interrupt handler returns with > > interrupts enabled. That's why IRQF_DISABLED became meaningless. > > Awesome. > > Can I politely ask that a reference to that commit and something like > your paragraph here explaining things is added to these IRQF_DISABLED > removal patches? That's a good idea. I'll let sed loose on the changelogs when I pick them up. Thanks, tglx