Return-path: Received: from nf-out-0910.google.com ([64.233.182.185]:11458 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751303AbYGYUAa (ORCPT ); Fri, 25 Jul 2008 16:00:30 -0400 Received: by nf-out-0910.google.com with SMTP id d3so1314820nfc.21 for ; Fri, 25 Jul 2008 13:00:28 -0700 (PDT) Date: Fri, 25 Jul 2008 22:01:37 +0200 From: Jarek Poplawski To: Johannes Berg Cc: Ingo Oeser , David Miller , 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: <20080725200137.GC3107@ami.dom.local> (sfid-20080725_220038_413077_2262A15A) References: <1216806614.7257.152.camel@twins> <1216810696.7257.175.camel@twins> <20080723.131441.200166513.davem@davemloft.net> <200807251904.37302.netdev@axxeo.de> <20080725183622.GA3107@ami.dom.local> <1217013384.4758.5.camel@johannes.berg> <20080725193416.GB3107@ami.dom.local> <1217014575.4758.7.camel@johannes.berg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1217014575.4758.7.camel@johannes.berg> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, Jul 25, 2008 at 09:36:15PM +0200, Johannes Berg wrote: > On Fri, 2008-07-25 at 21:34 +0200, Jarek Poplawski wrote: > > > > Umm, of course it cannot, because then we'd have to take the mutex in > > > the TX path, which we cannot. We cannot have another lock in the TX > > > path, what's so hard to understand about? We need to be able to lock all > > > queues to lock out multiple tx paths at once in some (really) slow paths > > > but not have any extra lock overhead for the tx path, especially not a > > > single lock. > > > > But this mutex doesn't have to be mutex. And it's not for the tx path, > > only for "service" just like netif_tx_lock(). The fast path needs only > > queue->tx_lock. > > No, we need to be able to lock out multiple TX paths at once. IMHO, it can do the same. We could e.g. insert a locked spinlock into this noop_tx_handler(), to give everyone some waiting. Jarek P.