From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19016 invoked by alias); 10 Apr 2006 10:59:15 -0000 Received: (qmail 19008 invoked by uid 22791); 10 Apr 2006 10:59:15 -0000 X-Spam-Check-By: sourceware.org Received: from anchor-post-33.mail.demon.net (HELO anchor-post-33.mail.demon.net) (194.217.242.91) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 10 Apr 2006 10:59:11 +0000 Received: from calivar.demon.co.uk ([83.104.54.243] helo=xl5.calivar.com) by anchor-post-33.mail.demon.net with esmtp (Exim 4.42) id 1FSu6t-0003td-9n; Mon, 10 Apr 2006 10:59:07 +0000 Received: from xl5.calivar.com (localhost [127.0.0.1]) by xl5.calivar.com (Postfix) with ESMTP id B1986138755; Mon, 10 Apr 2006 11:59:05 +0100 (BST) To: Sergei Organov Cc: ecos-discuss@ecos.sourceware.org References: <20060406211847.GH12221@lunn.ch> <20060409123238.GS12221@lunn.ch> <8764lhbthh.fsf@javad.com> From: Nick Garnett Original-Sender: nickg@ecoscentric.com Date: Mon, 10 Apr 2006 10:59:00 -0000 In-Reply-To: <8764lhbthh.fsf@javad.com> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Subject: Re: [ECOS] Re: DSR stops running after heavy interrupts. Bug found? X-SW-Source: 2006-04/txt/msg00112.txt.bz2 Sergei Organov writes: > A little OT while we are at interrupt_end(). Could you please explain > why > > #ifdef CYGPKG_KERNEL_SMP_SUPPORT > Cyg_Scheduler::lock(); > #endif > > is there at the beginning, -- looks like extra scheduler lock without > corresponding unlock for SMP case. If not a bug, it seems a comment > would be nice to have there. In SMP configurations we don't want to claim the scheduler lock in the interrupt VSR because it would block interrupts and scheduler operations on other CPUs. It also requires a spinlock to be claimed, which would require special code to be written -- it's much easier to do the job later. In HALs where SMP is supported, the usual scheduler lock increment is ifdeffed out. Perhaps a comment would be useful, but it seemed like the ifdef surrounding it would be sufficient indication that this was for SMP only. -- Nick Garnett eCos Kernel Architect http://www.ecoscentric.com The eCos and RedBoot experts -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss