From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28333C43613 for ; Fri, 21 Jun 2019 12:17:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7424F2084E for ; Fri, 21 Jun 2019 12:17:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="huF4BV7q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726750AbfFUMRC (ORCPT ); Fri, 21 Jun 2019 08:17:02 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:37184 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726260AbfFUMRC (ORCPT ); Fri, 21 Jun 2019 08:17:02 -0400 Received: by mail-wr1-f65.google.com with SMTP id v14so6378670wrr.4 for ; Fri, 21 Jun 2019 05:17:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=VViufnhkk9Q+Cc+Ah/mrAoTSgBMhZKq9tL/vgWAqr+4=; b=huF4BV7qLSAFkVBBOF2Frok/B9JTFxFb7nftqk4k0XrbGdNVoIXs7S46mNudg7Zbc4 hdXciGVrmr60AMFrbguv/KsVAatrblOSyFGL4UAPoq1d7+gIdy8hYH9vMfaDzxe1Oik6 nS3Dhl1bFo3IKkQsKvwv33OR8PEYJGnT3kK0M= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=VViufnhkk9Q+Cc+Ah/mrAoTSgBMhZKq9tL/vgWAqr+4=; b=Iyb+J//TDmAz/Geu6N5REfy7TAh37bUgw4uRocUgTANxjUL2t135ZthMhKUt5D/VWH luBfSWd4cdjAd9LhE0sgA0oEk99EkHAZiC28ipWpOUYM6J1W8qlrjv/w1PQhYPIE57ib Gy0+5AjqaA2JyZiB/z7ADiqbOt83+uxjEMO7vYWCbmLD4U09NbcmARmj90rJdc2rV5MI SEQpWrGoa2sQq4cHE3RC22FUhEBupgXpaSsgbT3mqo7nNDsivzJbRy6XEmh1wsGs9h3s RJCZkTfnF8alDw1moqt9f8HSLXVq/DGqXL/v3xVAkLbD2Pmc3OnSH9IwdkpVz9C4fDLK lqEQ== X-Gm-Message-State: APjAAAU5DdPlT+Dt6252oG2JCAXZaolPzCiD57Rp0NDZLrF6B26oMjT0 f8byaZsbFwwWZpOPUBRVYLYcfA== X-Google-Smtp-Source: APXvYqxQ0SoCYUdHTDXwfXXXvlUzsiiPyA3rr+Pgk0f4sGCWXIupKy2ymoNynC0OD4471a+7phrrSQ== X-Received: by 2002:adf:81c9:: with SMTP id 67mr25178358wra.62.1561119419744; Fri, 21 Jun 2019 05:16:59 -0700 (PDT) Received: from andrea (86.100.broadband17.iol.cz. [109.80.100.86]) by smtp.gmail.com with ESMTPSA id l19sm1649602wmj.33.2019.06.21.05.16.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 21 Jun 2019 05:16:59 -0700 (PDT) Date: Fri, 21 Jun 2019 14:16:53 +0200 From: Andrea Parri To: John Ogness Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Linus Torvalds , Greg Kroah-Hartman , Thomas Gleixner , Sergey Senozhatsky Subject: Re: [RFC PATCH v2 1/2] printk-rb: add a new printk ringbuffer implementation Message-ID: <20190621121653.GA9473@andrea> References: <20190607162349.18199-1-john.ogness@linutronix.de> <20190607162349.18199-2-john.ogness@linutronix.de> <20190618112237.GP3436@hirez.programming.kicks-ass.net> <87a7eebk71.fsf@linutronix.de> <20190619104655.GA6668@andrea> <87fto327ne.fsf@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87fto327ne.fsf@linutronix.de> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > FWIW (and as anticipated time ago in a private email), when I see code > > like this I tend to look elsewhere... ;-/ > > Do you really mean "code" or are you just referring to "code comments"? > If you really mean code, then I'd appreciate some feedback about what > should change. I really just meant "uncommented code". ;-) I do plan to read your: https://lkml.kernel.org/r/87k1df28x4.fsf@linutronix.de (and the code it's referring to) with due calm in the following days. Thank you in advance for these remarks. [Trying to address your question about herd7,] A list of supported primitives is available from: tools/memory-model/linux-kernel.def (left column) This includes cmpxchg() (and its variants: _relaxed(), _acquire() and _release()), however, herd7 can currently only parse statements like: loc_var = cmpxchg(addr, old, new); (and it will complain loudly without that "loc_var = " part...); this is something that could be improved, or at least it seems this way... A similar consideration holds for all the value-returning primitives. Thanks, Andrea