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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 383BEC4742C for ; Mon, 16 Nov 2020 12:47:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5E3A21527 for ; Mon, 16 Nov 2020 12:47:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="dBsOqD/D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727489AbgKPMqz (ORCPT ); Mon, 16 Nov 2020 07:46:55 -0500 Received: from ozlabs.org ([203.11.71.1]:42929 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726199AbgKPMqz (ORCPT ); Mon, 16 Nov 2020 07:46:55 -0500 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4CZTNY1Tgnz9sPB; Mon, 16 Nov 2020 23:46:52 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1605530813; bh=xMAELCkltgTjsJeMY4qaKQV8GQbtRxt8MjuwMsICxw8=; h=From:To:Subject:In-Reply-To:References:Date:From; b=dBsOqD/DynpKEywEw+z2q3N5AUsSU47Iiu0CkTJJLO3LWUEhRd+V+/1fL1iYhyufm t1AkaHqj0OaABp8q9ZkuZYVHOWPEb9yMQakO8Cxohlz5WnMdjgII5Mg2OYykKE6Wky hIlgxQ78xlGB+Yz+fXHTUN+Skkref2HlQvSfrZsuQYsyH3evNsFRnRlimoEsCv5qx9 Yd5Y5fEamtlrlymgMIH5FTm9MzPSDIe5ZLhgJcyGGBI+KlNx5CVPI3kucsyRoMUpoV OE6kpYlzcgCvIprg5R5T17/Qpm0juINfhvZsAyII0nF7VM/0y9n22MndytJBJDFnKp mG3G9iQ6mxvfw== From: Michael Ellerman To: Wang Qing , Benjamin Herrenschmidt , Paul Mackerras , Christophe Leroy , Nicholas Piggin , Jordan Niethe , Alistair Popple , Wang Qing , "Aneesh Kumar K.V" , Peter Zijlstra , Greg Kroah-Hartman , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V3] sched/rt, powerpc: Prepare for PREEMPT_RT In-Reply-To: <1604998411-16116-1-git-send-email-wangqing@vivo.com> References: <1604998411-16116-1-git-send-email-wangqing@vivo.com> Date: Mon, 16 Nov 2020 23:46:51 +1100 Message-ID: <871rgt4gg4.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Wang Qing writes: > PREEMPT_RT is a separate preemption model, CONFIG_PREEMPT will > be disabled when CONFIG_PREEMPT_RT is enabled, so we need > to add CONFIG_PREEMPT_RT output to __die(). > > Signed-off-by: Wang Qing Something fairly similar was posted previously. That time I said: I don't think there's any point adding the "_RT" to the __die() output until/if we ever start supporting PREEMPT_RT. https://lore.kernel.org/linuxppc-dev/87d0ext4q3.fsf@mpe.ellerman.id.au/ And I think I still feel the same way. It's not clear powerpc will ever support PREEMPT_RT, so this would just be confusing to people. And potentially someone will then send a patch to remove it as dead code. cheers > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > index 5006dcb..dec7b81 > --- a/arch/powerpc/kernel/traps.c > +++ b/arch/powerpc/kernel/traps.c > @@ -262,10 +262,11 @@ static int __die(const char *str, struct pt_regs *regs, long err) > { > printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); > > - printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n", > + printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s%s %s\n", > IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE", > PAGE_SIZE / 1024, get_mmu_str(), > IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", > + IS_ENABLED(CONFIG_PREEMPT_RT) ? " PREEMPT_RT" : "", > IS_ENABLED(CONFIG_SMP) ? " SMP" : "", > IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "", > debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", > -- > 2.7.4