From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756114AbZEMT5B (ORCPT ); Wed, 13 May 2009 15:57:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754662AbZEMT4t (ORCPT ); Wed, 13 May 2009 15:56:49 -0400 Received: from waste.org ([66.93.16.53]:45261 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753350AbZEMT4s (ORCPT ); Wed, 13 May 2009 15:56:48 -0400 Date: Wed, 13 May 2009 14:55:19 -0500 From: Matt Mackall To: Jeff Garzik Cc: Chris Peterson , linux-kernel@vger.kernel.org, NetDev Subject: Re: [PATCH] [resend] drivers/net: remove network drivers' last few uses of IRQF_SAMPLE_RANDOM Message-ID: <20090513195519.GL31071@waste.org> References: <20090513060850.GZ31071@waste.org> <20090513142535.GB31071@waste.org> <4A0B21DF.9050702@garzik.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A0B21DF.9050702@garzik.org> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 13, 2009 at 03:39:11PM -0400, Jeff Garzik wrote: > Matt Mackall wrote: > >On Wed, May 13, 2009 at 12:17:29AM -0700, Chris Peterson wrote: > >>>The future model will continue to sample network > >>>devices on theory that they -might- be less than 100% observable and > >>>that can only increase our total (unmeasurable) amount of entropy. > >>That sounds reasonable to me. So should all net drivers now specify > >>IRQF_SAMPLE_RANDOM? > >> > >>Or even simpler: could request_irq() assume IRQF_SAMPLE_RANDOM for any > >>interrupt that is not (say) IRQF_IRQPOLL or IRQF_PERCPU? > > > >Maybe. We don't want IRQ latency to suffer. So before we turn on > >sampling of -all- sources, we need to make sampling lighter weight and > >we need a way to say 'we have enough' so that we're not consuming CPU > >when our pools are 'full'. We could turn it on now and rely on the > >current trickle logic, but it's nice to have the water main off when > >doing significant plumbing. > > So, until such time, let's be consistent in net driver land and not > IRQF_SAMPLE_RANDOM. > > Jeff If you want. I was also looking to avoid the fight that happened when I submitted an equivalent patch a couple years back. -- Mathematics is the supreme nostalgia of our time.