From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f43.google.com (mail-wm0-f43.google.com [74.125.82.43]) by kanga.kvack.org (Postfix) with ESMTP id 71EAE6B0253 for ; Mon, 16 Nov 2015 03:47:43 -0500 (EST) Received: by wmww144 with SMTP id w144so99979144wmw.1 for ; Mon, 16 Nov 2015 00:47:43 -0800 (PST) Received: from e06smtp13.uk.ibm.com (e06smtp13.uk.ibm.com. [195.75.94.109]) by mx.google.com with ESMTPS id wo7si44532285wjb.160.2015.11.16.00.47.42 for (version=TLSv1 cipher=AES128-SHA bits=128/128); Mon, 16 Nov 2015 00:47:42 -0800 (PST) Received: from localhost by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 16 Nov 2015 08:47:42 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 46D0717D8063 for ; Mon, 16 Nov 2015 08:48:00 +0000 (GMT) Received: from d06av10.portsmouth.uk.ibm.com (d06av10.portsmouth.uk.ibm.com [9.149.37.251]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id tAG8ldVO41418768 for ; Mon, 16 Nov 2015 08:47:39 GMT Received: from d06av10.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av10.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id tAG7ldUf011247 for ; Mon, 16 Nov 2015 00:47:40 -0700 Date: Mon, 16 Nov 2015 09:47:37 +0100 From: Martin Schwidefsky Subject: Re: [linux-next:master 12891/13017] mm/slub.c:2396:1: warning: '___slab_alloc' uses dynamic stack allocation Message-ID: <20151116094737.270168cc@mschwide> In-Reply-To: <201511131414.tADEE1co028795@d06av10.portsmouth.uk.ibm.com> References: <201511111413.65wysS6A%fengguang.wu@intel.com> <20151111124108.53df1f48218c1366f9e763f0@linux-foundation.org> <20151113125200.319a3101@mschwide> <201511131414.tADEE1co028795@d06av10.portsmouth.uk.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andreas Krebbel1 Cc: mschwid2@linux.vnet.ibm.com, Andrew Morton , Christoph Lameter , kbuild test robot , heicars2@linux.vnet.ibm.com, kbuild-all@01.org, Linux Memory Management List On Fri, 13 Nov 2015 16:13:46 +0100 "Andreas Krebbel1" wrote: > this appears to be the result of aligning struct page to more than 8 bytes > and putting it onto the stack - wich is only 8 bytes aligned. The > compiler has to perform runtime alignment to achieve that. It allocates > memory using *alloca* and does the math with the returned pointer. Our > dynamic stack allocation option basically only checks if there is an > alloca user. I can confirm that this is caused by the struct page alignment, if I force HAVE_ALIGNED_STRUCT_PAGE=n the warning vanishes. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- 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