From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f177.google.com (mail-pd0-f177.google.com [209.85.192.177]) by kanga.kvack.org (Postfix) with ESMTP id 0642E6B0262 for ; Sat, 19 Oct 2013 18:39:57 -0400 (EDT) Received: by mail-pd0-f177.google.com with SMTP id p10so3774448pdj.36 for ; Sat, 19 Oct 2013 15:39:57 -0700 (PDT) Received: from psmtp.com ([74.125.245.153]) by mx.google.com with SMTP id dl5si4523095pbd.236.2013.10.19.15.39.56 for ; Sat, 19 Oct 2013 15:39:57 -0700 (PDT) From: Andi Kleen Subject: Re: [PATCH v2 00/15] slab: overload struct slab over struct page to reduce memory usage References: <1381913052-23875-1-git-send-email-iamjoonsoo.kim@lge.com> <20131016133457.60fa71f893cd2962d8ec6ff3@linux-foundation.org> Date: Sat, 19 Oct 2013 15:39:34 -0700 In-Reply-To: <20131016133457.60fa71f893cd2962d8ec6ff3@linux-foundation.org> (Andrew Morton's message of "Wed, 16 Oct 2013 13:34:57 -0700") Message-ID: <8738nwvqah.fsf@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Joonsoo Kim , Pekka Enberg , Christoph Lameter , Joonsoo Kim , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Wanpeng Li Andrew Morton writes: > > One example is mm/memory-failure.c:memory_failure(). It starts with a > raw pfn, uses that to get at the `struct page', then starts playing > around with it. Will that code still work correctly when some of the > page's fields have been overlayed with slab-specific contents? As long as PageSlab() works correctly memory_failure should be happy. > > This issue hasn't been well thought through. Given a random struct > page, there isn't any protocol to determine what it actually *is*. > It's a plain old variant record, but it lacks the agreed-upon tag field > which tells users which variant is currently in use. PageSlab() should work for this right? For the generic case it may not though. -Andi -- ak@linux.intel.com -- Speaking for myself only -- 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