From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Date: Mon, 21 Sep 2009 09:30:26 +0000 Subject: Re: [PATCH] remove duplicate asm/mman.h files Message-Id: <200909211130.26377.arnd@arndb.de> List-Id: References: <200909211031.25369.arnd@arndb.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Rientjes Cc: Andrew Morton , Fenghua Yu , Tony Luck , ebmunson@us.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-man@vger.kernel.org, mtk.manpages@gmail.com, randy.dunlap@oracle.com, rth@twiddle.net, ink@jurassic.park.msu.ru, linux-ia64@vger.kernel.org On Monday 21 September 2009, David Rientjes wrote: > > I tried not to change the ABI in any way in my patch, and there is > > a theoretical possibility that some user space program on ia64 currently > > depends on that definition. > > > > I don't buy that as justification, if some userspace program uses it based > on the false belief that it actually does what it says, it's probably > better to break their build than perpetuating the lie that it's different > than ~MAP_GROWSDOWN. It's more a matter of principle of my patches. I try to strictly separate patches that move code around (like the one I sent) from those that change contents (like yours, or the one before that adds MAP_STACK and MAP_HUGETLB). Removing a definition from an exported header file either requires specific knowledge about why it is there to start with, or more research on the topic than I wanted to do. For instance, a theoretical program might have a helper function correctly doing void *xmmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) { if (flags & MAP_GROWSUP) { /* MAP_GROWSUP is not supported */ errno = -EINVAL; return MAP_FAILED; } return mmap(addr, length, prot, flags, fd, offset); } Of course, such a program would only work on ia64 currently, so it should be safe to make ia64 behave like the other architectures in this regard. > ia64: remove definition for MAP_GROWSUP > > MAP_GROWSUP is unused. > > Signed-off-by: David Rientjes Acked-by: Arnd Bergmann