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=-3.5 required=3.0 tests=BAYES_00, BUG6152_INVALID_DATE_TZ_ABSURD,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS,INVALID_DATE_TZ_ABSURD,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 2C025C433E4 for ; Tue, 21 Jul 2020 14:57:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BA7F20729 for ; Tue, 21 Jul 2020 14:57:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="juG+CQsX"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="3VdtYT2N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728835AbgGUO5T (ORCPT ); Tue, 21 Jul 2020 10:57:19 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:40598 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726710AbgGUO5T (ORCPT ); Tue, 21 Jul 2020 10:57:19 -0400 From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1595343436; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=G0hd/HqaHi+sC5Cb/7dGS7Dm/p8jgsSDeWCrD5MiSf4=; b=juG+CQsXZv88giGDNbib+yxQ7AH8kThmTUETtnS/AMQXOiZYX3HSdSn2fYZBFcwuYvef6X faXflTdSJIBmnO3hCQ8yV5tpRcWctTB4tBaZB8LFwMM8mfFm1Wgwpr0dOnF4A5rrsc8Tnk NDkXRXPalGpp7cjP0Uev0oW+rYNr17Ua69V5lH5yY+FgluFWEAUXQgdMVffgWaWMu6kP3M 4o1hnbqfHm11hfKB8yeOJySZTwpcdr/ku1L3nVZdgBQGG1Qw4tldSqEdRKLX7xnox4zvhK GvmtKcPLV2LhtLNlPOcOzHOGC6BqCoWWqJegdEUeBjLNFaCWKVLS2IxqUkcoZQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1595343436; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=G0hd/HqaHi+sC5Cb/7dGS7Dm/p8jgsSDeWCrD5MiSf4=; b=3VdtYT2N6f8es2zunWzjp7EoGj+vK0PfjSnVPq9/w9hn5A+/lljl6eoSVy9EKWs20R6ySm 5KA8TAfuhGSYFUDw== To: Sergey Senozhatsky , Linus Torvalds Cc: Sergey Senozhatsky , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Greg Kroah-Hartman , Peter Zijlstra , Thomas Gleixner , kexec@lists.infradead.org, Linux Kernel Mailing List Subject: Re: [PATCH 2/4] printk: store instead of processing cont parts In-Reply-To: <20200721144220.GE44523@jagdpanzerIV.localdomain> References: <20200717234818.8622-1-john.ogness@linutronix.de> <20200717234818.8622-3-john.ogness@linutronix.de> <20200719143527.GA566@jagdpanzerIV.localdomain> <20200720015057.GA463@jagdpanzerIV.localdomain> <20200721144220.GE44523@jagdpanzerIV.localdomain> Date: Tue, 21 Jul 2020 17:03:16 +0206 Message-ID: <87ft9kx6er.fsf@jogness.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-07-21, Sergey Senozhatsky wrote: >> That said, we have traditionally used not just "current process", but >> also "last irq-level" as the context information, so I do think it >> would be good to continue to do that. > > OK, so basically, extending printk_caller_id() so that for IRQ/NMI > we will have more info than just "0x80000000 + raw_smp_processor_id()". If bit31 is set, the upper 8 bits could specify what the lower 24 bits represent. That would give some freedom for the future. For example: 0x80 = cpu id (generic context) 0x81 = interrupt number 0x82 = cpu id (nmi context) Or maybe ascii should be used instead? 0x80 | '\0' = cpu id (generic context) 0x80 | 'i' = interrupt number 0x80 | 'n' = cpu id (nmi context) Just an idea. John Ogness