Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934589Ab3IDJ1p (ORCPT ); Wed, 4 Sep 2013 05:27:45 -0400 Received: from mail-pd0-f176.google.com ([209.85.192.176]:44363 "EHLO mail-pd0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934484Ab3IDJ1n (ORCPT ); Wed, 4 Sep 2013 05:27:43 -0400 MIME-Version: 1.0 In-Reply-To: <5226F9BF.8040304@asianux.com> References: <52005571.4080704@asianux.com> <52268800.2010200@asianux.com> <5226EAAE.6090500@asianux.com> <5226F9BF.8040304@asianux.com> Date: Wed, 4 Sep 2013 11:27:43 +0200 X-Google-Sender-Auth: IPLRMx6VO5mt2KNq_ECzY0t4FrA Message-ID: Subject: Re: [PATCH trivial] UAPI: Kbuild: add/modify comments for "uapi/Kbuild" and "uapi/linux/Kbuild" From: Geert Uytterhoeven To: Chen Gang Cc: Jiri Kosina , Paul McKenney , "dhowells@redhat.com" , Thomas Gleixner , Dave Jones , Arnd Bergmann , David Miller , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1948 Lines: 45 On Wed, Sep 4, 2013 at 11:13 AM, Chen Gang wrote: >>> Hmm... why we need "uapi/linux/" ? (I can not find some related >>> documents, so I have to 'guess'). >> >> The "uapi" subdirectories are there to distinguish userspace headers from >> kernelspace headers, and allow both to live in the kernel source tree. >> >> When running "make headers_install", the (processed) headers in the >> various "uapi" subdirectories are copied to /usr/include. >> Hence "uapi/linux/foo.h" becomes in userspace. >> In userspace there are no "uapi" subdirectories anymore. >> > > Yeah, so why need another "uapi/*" excluding "uapi/linux" ? > > Are they also truly still "Userspace API" but which need not distinguish > ? (at least, it seems that idea is not quite good). > > Hmm... maybe the "uapi/*" except "uapi/linux" are also installed? Is it > for compatible (originally they are here, and now we have to follow, it > is no reason to change if not find related critical issues)? All uapi files are installed, a.o. /usr/include/scsi/, /usr/include/video/, ... Historically, everything under "include" in the kernel source tree was installed in /usr/include/, after (semi)manual cleanup. Since the uapi split, everything is handled automatically. Because of compatibility reasons (do not break userspace), paths had to stay the same. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/