From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f171.google.com (mail-io0-f171.google.com [209.85.223.171]) by kanga.kvack.org (Postfix) with ESMTP id C31DA6B0265 for ; Fri, 13 Nov 2015 10:22:50 -0500 (EST) Received: by iofh3 with SMTP id h3so100510939iof.3 for ; Fri, 13 Nov 2015 07:22:50 -0800 (PST) Received: from resqmta-ch2-01v.sys.comcast.net (resqmta-ch2-01v.sys.comcast.net. [2001:558:fe21:29:69:252:207:33]) by mx.google.com with ESMTPS id m9si6104360igx.48.2015.11.13.07.22.50 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 13 Nov 2015 07:22:50 -0800 (PST) Date: Fri, 13 Nov 2015 09:22:48 -0600 (CST) From: Christoph Lameter Subject: Re: [linux-next:master 12891/13017] mm/slub.c:2396:1: warning: '___slab_alloc' uses dynamic stack allocation In-Reply-To: <201511131513.tADFDwJN030997@d06av03.portsmouth.uk.ibm.com> Message-ID: References: <201511111413.65wysS6A%fengguang.wu@intel.com><20151111124108.53df1f48218c1366f9e763f0@linux-foundation.org> <20151113125200.319a3101@mschwide> <201511131513.tADFDwJN030997@d06av03.portsmouth.uk.ibm.com> Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Andreas Krebbel1 Cc: mschwid2@linux.vnet.ibm.com, Andrew Morton , kbuild test robot , heicars2@linux.vnet.ibm.com, kbuild-all@01.org, Linux Memory Management List On Fri, 13 Nov 2015, 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. The slub uses of struct page only require an alignment of the page struct on the stack to a word. So its fine. -- 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