From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Date: Fri, 06 Feb 2009 15:55:12 +0000 Subject: Re: [linux-next][PATCH] revert headers_check fix: ia64, fpu.h Message-Id: <20090206155512.GF13758@n2100.arm.linux.org.uk> List-Id: References: <20090206164546.6291.KOSAKI.MOTOHIRO@jp.fujitsu.com> <3f9a31f40902060053x18dacf58u40c739ab89f13860@mail.gmail.com> <20090206180957.6294.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20090206145556.GH18368@elte.hu> <1233934141.3209.20.camel@localhost.localdomain> <20090206153315.GD13758@n2100.arm.linux.org.uk> <1233935328.3209.30.camel@localhost.localdomain> In-Reply-To: <1233935328.3209.30.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jaswinder Singh Rajput Cc: Ingo Molnar , KOSAKI Motohiro , Jaswinder Singh Rajput , Linus Torvalds , Sam Ravnborg , Andrew Morton , hskinnemoen@atmel.com, cooloney@kernel.org, tony.luck@intel.com, ralf@linux-mips.org, dhowells@redhat.com, matthew@wil.cx, chris@zankel.net, LKML , linux-next , linux-ia64 On Fri, Feb 06, 2009 at 09:18:48PM +0530, Jaswinder Singh Rajput wrote: > On Fri, 2009-02-06 at 15:33 +0000, Russell King - ARM Linux wrote: > > On Fri, Feb 06, 2009 at 08:59:01PM +0530, Jaswinder Singh Rajput wrote: > > > Jaswinder Singh Rajput (2): > > > Neither asm/types.h nor linux/types.h is required for arch/ia64/include/asm/fpu.h > > > make linux/types.h as assembly safe > > > > I continue to disagree with the need for the second patch. > > Like Ingo suggested: > > On Fri, 2009-02-06 at 15:58 +0100, Ingo Molnar wrote: > > Well types.h easily gets included in other files though, which might be > > partially suited for assembly - and have !__ASSEMBLY__ portions that rely on > > a types.h include. > > > > So making this file an invariant in .S files does not sound like a bad idea > > to me. Is there any downside? > > > > We cannot see any downside of this patch. > > But we can see upside of this patch is: > 1. No need to protect linux/types.h with #ifndef __ASSEMBLY__ in many > files > 2. So we trying to replace multiple #ifndef __ASSEMBLY__ with one. The point is: 1. If the parent include needs to include linux/types.h to get at C types _and_ the include file needs to also be included by assembly code, it itself needs to have #ifndef __ASSEMBLY__ to protect those uses from the assembly code. In that case, the linux/types.h include should be contained within the #ifndef __ASSEMBLY__ .. #endif block along with all C only parts of the header file. 2. if it doesn't need C types from linux/types.h, then that header has no business including linux/types.h, and the include should be eliminated to save the already dirbolically slow compiler from having to read and parse that file, and more importantly allowing it to eliminate linux/types.h from the build dependencies. Yes, you can wrap linux/types.h with that ifndef, and yes it will fix any problems, but I view it as a hack rather than fixing the real problem which is lazyness by code writers to get their include dependencies right.