From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Getz Subject: Re: IRQF_SAMPLE_RANDOM question... Date: Thu, 9 Apr 2009 09:54:54 -0400 Message-ID: <200904090954.54601.rgetz@blackfin.uclinux.org> References: <200904061430.26276.rgetz@blackfin.uclinux.org> <200904071744.17727.rgetz@blackfin.uclinux.org> <1239220294.31467.55.camel@calx> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Chris Peterson" To: "Matt Mackall" Return-path: Received: from nwd2mail11.analog.com ([137.71.25.57]:45193 "EHLO nwd2mail11.analog.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764387AbZDINwz (ORCPT ); Thu, 9 Apr 2009 09:52:55 -0400 In-Reply-To: <1239220294.31467.55.camel@calx> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Wed 8 Apr 2009 15:51, Matt Mackall pondered: > On Tue, 2009-04-07 at 17:44 -0400, Robin Getz wrote: > > Is that "Everything in general, with a few exceptions", or > > "__Everything__"? > > Everything. We want every input point to better document the type of > entropy source. OK - any objections to something like this? =================================================================== --- Documentation/feature-removal-schedule.txt (revision 6236) +++ Documentation/feature-removal-schedule.txt (working copy) @@ -6,6 +6,19 @@ --------------------------- +What: IRQF_SAMPLE_RANDOM +Check: IRQF_SAMPLE_RANDOM +When: July 2009 +Why: Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy + sources in the kernel's current entropy model. To resolve this, every + input point to the kernel's entropy pool needs to better document the + type of entropy source it actually is. This will be replaced with + additional add_*_randomness functions in drivers/char/random.c + +Who: Robin Getz & Matt Mackall + +--------------------------- + Then if someone attempts to add it, and runs checkpatch, it will generate something like: -------- ERROR: Don't use IRQF_SAMPLE_RANDOM(): see Documentation/feature-removal-schedule.txt #10: FILE: serial/bfin_5xx.c:650: + if (request_irq(uart->port.irq, bfin_serial_rx_int, IRQF_DISABLED | IRQF_SAMPLE_RANDOM, -------- My only real question is on the date... In a previous email: On Mon 6 Apr 2009 15:01, Matt Mackall pondered: > I'm eventually going to move the RNG away from the strict theoretical > entropy accounting model to a more pragmatic one which will be much > happier with iffy entropy sources, but that's a ways off. I was not sure what "a ways off" was defined as - or are the two (removal of IRQF_SAMPLE_RANDOM, and the pragmatic entropy accounting model) separate in your mind? I guess various add_*_randomness functions can be added today, and change how they are accounted for in the future? -Robin