From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id D0F6A6B0071 for ; Tue, 12 Jan 2010 03:05:02 -0500 (EST) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o0C850Bq008264 for (envelope-from d.hatayama@jp.fujitsu.com); Tue, 12 Jan 2010 17:05:00 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 0C0C945DE51 for ; Tue, 12 Jan 2010 17:05:00 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id D7F0E45DE55 for ; Tue, 12 Jan 2010 17:04:59 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id B6DF8EF8002 for ; Tue, 12 Jan 2010 17:04:59 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 5B80F1DB803C for ; Tue, 12 Jan 2010 17:04:56 +0900 (JST) Date: Tue, 12 Jan 2010 17:05:03 +0900 (JST) Message-Id: <20100112.170503.112616928.d.hatayama@jp.fujitsu.com> Subject: Re: [RESEND][mmotm][PATCH v2, 0/5] elf coredump: Add extended numbering support From: Daisuke HATAYAMA In-Reply-To: <20100111192418.5cd8a554.akpm@linux-foundation.org> References: <20100107162928.1d6eba76.akpm@linux-foundation.org> <20100112.121232.189721840.d.hatayama@jp.fujitsu.com> <20100111192418.5cd8a554.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mhiramat@redhat.com, xiyou.wangcong@gmail.com, andi@firstfloor.org, jdike@addtoit.com, tony.luck@intel.com List-ID: From: Andrew Morton Subject: Re: [RESEND][mmotm][PATCH v2, 0/5] elf coredump: Add extended numbering support Date: Mon, 11 Jan 2010 19:24:18 -0800 > On Tue, 12 Jan 2010 12:12:32 +0900 (JST) Daisuke HATAYAMA wrote: > > > From: Andrew Morton > > Subject: Re: [RESEND][mmotm][PATCH v2, 0/5] elf coredump: Add extended numbering support > > Date: Thu, 7 Jan 2010 16:29:28 -0800 > > > > > On Mon, 04 Jan 2010 10:06:07 +0900 (JST) > > > Daisuke HATAYAMA wrote: > > > > > > > The current ELF dumper can produce broken corefiles if program headers > > > > exceed 65535. In particular, the program in 64-bit environment often > > > > demands more than 65535 mmaps. If you google max_map_count, then you > > > > can find many users facing this problem. > > > > > > > > Solaris has already dealt with this issue, and other OSes have also > > > > adopted the same method as in Solaris. Currently, Sun's document and > > > > AMD 64 ABI include the description for the extension, where they call > > > > the extension Extended Numbering. See Reference for further information. > > > > > > > > I believe that linux kernel should adopt the same way as they did, so > > > > I've written this patch. > > > > > > > > I am also preparing for patches of GDB and binutils. > > > > > > That's a beautifully presented patchset. Thanks for doing all that > > > work - it helps. > > > > > > UML maintenance appears to have ceased in recent times, so if we wish > > > to have these changes runtime tested (we should) then I think it would > > > be best if you could find someone to do that please. > > > > > > And no akpm code-review would be complete without: dump_seek() is > > > waaaay to large to be inlined. Is there some common .c file to where > > > we could move it? > > > > > > > I am sorry for very late reply. > > > > * Patch Test for UML-i386 > > > > I tested on UML-i386 for the stable release of that time, precisely > > 2.6.32, since even building process for UML-i386 failed for mainline > > and mmotm trees, as you've expected. > > > > I don't know internal UML implementation at all, so I need to find > > someone if runtime test for mmotm tree is absolutely necessary. > > OK, thanks. > > > * modification for dump_seek() > > > > I couldn't find any right .c file at which dump_seek() be placed. We > > need to create a new .c file into which we put auxiliary functions to > > generate/manipulate coredumps. > > Sure, that sounds appropriate. > > > There is another problem regarding name space. The name dump_seek() is > > too short. If we move dump_seek() to some .c file, we need to rename > > it according to the corresponding object file format, such as > > elf_core_dump_seek() or aout_dump_seek(); or coredump_dump_seek(), as > > currently dump_seek() is shared among dumping processes in multiple > > object formats. > > I don't understand. Your current inlined dump_seek() looks like it > will work OK for all dump formats when uninlined? > My concern is possibility of dump_seek()'s very short and general naming wasting public name space and colliding other global names. My idea is, for example, to rename it coredump_dump_seek(). Please ignore remaining part of the previous explanation. As you mention, current dump_seek() implementation is no problem. When it will be needed is one of implementations of some object file format will fork. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org