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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 EA289C07E85 for ; Tue, 11 Dec 2018 13:00:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5F6420849 for ; Tue, 11 Dec 2018 13:00:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nifty.com header.i=@nifty.com header.b="KUzYHY86" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A5F6420849 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=socionext.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726519AbeLKNAO (ORCPT ); Tue, 11 Dec 2018 08:00:14 -0500 Received: from conssluserg-05.nifty.com ([210.131.2.90]:30117 "EHLO conssluserg-05.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726203AbeLKNAO (ORCPT ); Tue, 11 Dec 2018 08:00:14 -0500 Received: from mail-ua1-f41.google.com (mail-ua1-f41.google.com [209.85.222.41]) (authenticated) by conssluserg-05.nifty.com with ESMTP id wBBD02hW027415; Tue, 11 Dec 2018 22:00:03 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-05.nifty.com wBBD02hW027415 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1544533203; bh=twubWNm7C/dHzNFwoFHVCUMciZ0Sld3ahZ1E7w/D48Q=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=KUzYHY86ID8JjhXQ6Ey2ZIpONlHlRutHRwgJBti2rHRSozoW00BY2kn/r/mT7SShH 7Jv5WJ0xKj8X/b6FBGgDFybditq/MO64GzZrN1JxTLx0H770Pkej3N+p3QdFSGXjuK SCi7YaGh48TBDJW3rg35i3bgcX5/pDoZ1E5XtsqxwsyBf8S99plf7UvkYZY3Unnlw+ oOjjl3ia1QXUTtIzZWEwZro3g0DfD7q6Bu9DGG3mfUB7FAkpNMgZeVKne/Za9HgpF2 TsbM0OyPGU4Sz+VWbA20/BfC2HR3QYYplUqUP7qLvl+eT1Q6i1C7knx1daTUtSyE0y +0TubPkvbpJeg== X-Nifty-SrcIP: [209.85.222.41] Received: by mail-ua1-f41.google.com with SMTP id e16so5069081uam.12; Tue, 11 Dec 2018 05:00:03 -0800 (PST) X-Gm-Message-State: AA+aEWb4jrFmOXNjnRt47e9bXBzoPyptyMPzwwm5UJbuPJWav1Vq2THG HD/iDXWYI9bRNq6Xt0LrIvLCq3wu/SbWc7cuz0s= X-Google-Smtp-Source: AFSGD/VqzOYRbYT45HUtGTBbZIr4xjI6beS8S0eCVtRR639tWGfJa672xNME7Tgo1tY98gGLM+L1YJnc5uvfT2jUn3I= X-Received: by 2002:ab0:6705:: with SMTP id q5mr7405382uam.89.1544533202351; Tue, 11 Dec 2018 05:00:02 -0800 (PST) MIME-Version: 1.0 References: <1544009286-15705-1-git-send-email-yamada.masahiro@socionext.com> <1544009286-15705-2-git-send-email-yamada.masahiro@socionext.com> <20181206150325.GA2726@infradead.org> In-Reply-To: <20181206150325.GA2726@infradead.org> From: Masahiro Yamada Date: Tue, 11 Dec 2018 21:59:26 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 2/3] kbuild: generate asm-generic wrappers if mandatory headers are missing To: Christoph Hellwig Cc: Linux Kbuild mailing list , Sam Ravnborg , "open list:DOCUMENTATION" , Linux Kernel Mailing List , Jonathan Corbet , Michal Marek Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, On Fri, Dec 7, 2018 at 12:04 AM Christoph Hellwig wrote: > > On Wed, Dec 05, 2018 at 08:28:05PM +0900, Masahiro Yamada wrote: > > Some time ago, Sam pointed out a certain degree of overwrap between > > generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121) > > > > I a bit tweaked the meaning of mandatory-y; now it defines the minimum > > set of ASM headers that all architectures must have. > > > > If arch does not have specific implementation of a mandatory header, > > Kbuild will let it fallback to the asm-generic one by automatically > > generating a wrapper. This will allow to drop lots of redundant > > generic-y defines. > > > > Previously, "mandatory" was used in the context of UAPI, but I guess > > this can be extended to kernel space ASM headers. > > How useful is it to keep the generic-y behavior around at all vs making > everything useful mandatory? What I can tell is not all architectures support kvm_para.h, ucontext.h I guess they will stay as arch-specific generic-y, but I am not an expert in this area. kvm_para.h is missing csky, nds32, riscv. ucontext.h is missing in alpha, arm, m68k, parisc, sparc, xtensa bpf_perf_event.h could be promoted to mandatory-y ? All architectures have it. -- Best Regards Masahiro Yamada