From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx141.postini.com [74.125.245.141]) by kanga.kvack.org (Postfix) with SMTP id 6761E6B0044 for ; Tue, 24 Apr 2012 01:34:44 -0400 (EDT) Message-ID: <4F963B8E.9030105@kernel.org> Date: Tue, 24 Apr 2012 14:35:10 +0900 From: Minchan Kim MIME-Version: 1.0 Subject: Re: [RFC] propagate gfp_t to page table alloc functions References: <1335171318-4838-1-git-send-email-minchan@kernel.org> <4F963742.2030607@jp.fujitsu.com> In-Reply-To: <4F963742.2030607@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Ingo Molnar , x86@kernel.org, Hugh Dickins , Johannes Weiner , Rik van Riel , Mel Gorman , kosaki.motohiro@jp.fujitsu.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org On 04/24/2012 02:16 PM, KAMEZAWA Hiroyuki wrote: > (2012/04/23 17:55), Minchan Kim wrote: > >> As I test some code, I found a problem about deadlock by lockdep. >> The reason I saw the message is __vmalloc calls map_vm_area which calls >> pud/pmd_alloc without gfp_t. so although we call __vmalloc with >> GFP_ATOMIC or GFP_NOIO, it ends up allocating pages with GFP_KERNEL. >> The should be a BUG. This patch fixes it by passing gfp_to to low page >> table allocate functions. >> >> Signed-off-by: Minchan Kim > > > Hmm ? vmalloc should support GFP_ATOMIC ? I'm not sure but alloc_large_system_hash already has used. And it's not specific on GFP_ATOMIC. We have to care of GFP_NOFS and GFP_NOIO to prevent deadlock on reclaim context. There are some places to use GFP_NOFS and we don't emit any warning message in case of that. > > And, do we need to change all pud_,pgd_,pmd_,pte_alloc() for users pgtables ? Maybe. -- Kind regards, Minchan Kim -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org