From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757069AbZATPyD (ORCPT ); Tue, 20 Jan 2009 10:54:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761526AbZATPxt (ORCPT ); Tue, 20 Jan 2009 10:53:49 -0500 Received: from cantor.suse.de ([195.135.220.2]:39374 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761312AbZATPxs (ORCPT ); Tue, 20 Jan 2009 10:53:48 -0500 Message-ID: <4975F376.4010506@suse.com> Date: Tue, 20 Jan 2009 10:53:26 -0500 From: Jeff Mahoney Organization: SUSE Labs, Novell, Inc User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Andrew Morton , Linus Torvalds Cc: Linux Kernel Mailing List Subject: [PATCH] kmalloc: Return NULL instead of link failure X-Enigmail-Version: 0.95.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The SLAB kmalloc with a constant value isn't consistent with the other implementations because it bails out with __you_cannot_kmalloc_that_much rather than returning NULL and properly allowing the caller to fall back to vmalloc or take other action. This doesn't happen with a non-constant value or with SLOB or SLUB. Starting with 2.6.28, I've been seeing build failures on s390x. This is due to init_section_page_cgroup trying to allocate 2.5MB when the max size for a kmalloc on s390x is 2MB. It's failing because the value is constant. The workarounds at the call size are ugly and the caller shouldn't have to change behavior depending on what the backend of the API is. So, this patch eliminates the link failure and returns NULL like the other implementations. Signed-off-by: Jeff Mahoney - --- include/linux/slab_def.h | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) - --- a/include/linux/slab_def.h +++ b/include/linux/slab_def.h @@ -43,10 +43,7 @@ static inline void *kmalloc(size_t size, i++; #include #undef CACHE - - { - - extern void __you_cannot_kmalloc_that_much(void); - - __you_cannot_kmalloc_that_much(); - - } + return NULL; found: #ifdef CONFIG_ZONE_DMA if (flags & GFP_DMA) @@ -77,10 +74,7 @@ static inline void *kmalloc_node(size_t i++; #include #undef CACHE - - { - - extern void __you_cannot_kmalloc_that_much(void); - - __you_cannot_kmalloc_that_much(); - - } + return NULL; found: #ifdef CONFIG_ZONE_DMA if (flags & GFP_DMA) - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkl183YACgkQLPWxlyuTD7IMnQCfbf4NvJuyTustFrdJD/lcl6ub QQ0AniWOsKCWnBWuLLnm6rM+Atq6LBfd =/evL -----END PGP SIGNATURE-----