Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759314AbYG0UiU (ORCPT ); Sun, 27 Jul 2008 16:38:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758143AbYG0UiC (ORCPT ); Sun, 27 Jul 2008 16:38:02 -0400 Received: from ug-out-1314.google.com ([66.249.92.175]:30174 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757739AbYG0UiB (ORCPT ); Sun, 27 Jul 2008 16:38:01 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=p/YEDtNsT48oQK/liRzEglrdzYaT/Eo4TfhB9WcFVyLehIGPvyjFlEkg3QCxRc7EpP Zqgqo4mBqPs21/1IUZLP0sOEvJu0XrAltcQ7mkRa+RgSimqmYBtiIXA5ZO+qx6mGalce zwrO4B9afKpBtzzRh3vZRmcfxULnHxx6OuQQM= Date: Sun, 27 Jul 2008 22:37:57 +0200 From: Jarek Poplawski To: David Miller Cc: johannes@sipsolutions.net, netdev@axxeo.de, peterz@infradead.org, Larry.Finger@lwfinger.net, kaber@trash.net, torvalds@linux-foundation.org, akpm@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, mingo@redhat.com Subject: Re: Kernel WARNING: at net/core/dev.c:1330 __netif_schedule+0x2c/0x98() Message-ID: <20080727203757.GA2527@ami.dom.local> References: <20080725200137.GC3107@ami.dom.local> <20080726.021846.236624483.davem@davemloft.net> <20080726131838.GA2873@ami.dom.local> <20080726.173434.48036095.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080726.173434.48036095.davem@davemloft.net> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1235 Lines: 31 On Sat, Jul 26, 2008 at 05:34:34PM -0700, David Miller wrote: > From: Jarek Poplawski > Date: Sat, 26 Jul 2008 15:18:38 +0200 > > > I guess some additional synchronization will be added yet to prevent > > parallel freeze and especially unfreeze. > > Yes, that could be a problem. Using test_and_set_bit() can > guard the freezing sequence itself, but it won't handle > letting two threads of control freeze and unfreeze safely > without a reference count. > > We want this thing to be able to be used flexbly, which means > we can't just assume that this is a short code sequence and > the unfreeze will come quickly. That pretty much rules > out using a new lock around the operation or anything > like that. > > So I guess we could replace the state bit with a reference > count. It doesn't even need to be atomic since it is set > and tested under dev_queue->_xmit_lock Looks like enough to me. (Probably it could even share space with the state.) Jarek P. -- 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/