From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f172.google.com (mail-pf0-f172.google.com [209.85.192.172]) by kanga.kvack.org (Postfix) with ESMTP id 013DF6B0005 for ; Tue, 26 Jan 2016 23:38:44 -0500 (EST) Received: by mail-pf0-f172.google.com with SMTP id q63so113737515pfb.1 for ; Tue, 26 Jan 2016 20:38:43 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id b14si6684133pfd.63.2016.01.26.20.38.43 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Jan 2016 20:38:43 -0800 (PST) Date: Tue, 26 Jan 2016 20:40:13 -0800 From: Andrew Morton Subject: Re: [PATCH 00/16] mm/slab: introduce new freed objects management way, OBJFREELIST_SLAB Message-Id: <20160126204013.a065301b.akpm@linux-foundation.org> In-Reply-To: <1452749069-15334-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1452749069-15334-1-git-send-email-iamjoonsoo.kim@lge.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: Joonsoo Kim Cc: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Jesper Dangaard Brouer , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, 14 Jan 2016 14:24:13 +0900 Joonsoo Kim wrote: > This patchset implements new freed object management way, that is, > OBJFREELIST_SLAB. Purpose of it is to reduce memory overhead in SLAB. > > SLAB needs a array to manage freed objects in a slab. If there is > leftover after objects are packed into a slab, we can use it as > a management array, and, in this case, there is no memory waste. > But, in the other cases, we need to allocate extra memory for > a management array or utilize dedicated internal memory in a slab for it. > Both cases causes memory waste so it's not good. > > With this patchset, freed object itself can be used for a management > array. So, memory waste could be reduced. Detailed idea and numbers > are described in last patch's commit description. Please refer it. > > In fact, I tested another idea implementing OBJFREELIST_SLAB with > extendable linked array through another freed object. It can remove > memory waste completely but it causes more computational overhead > in critical lock path and it seems that overhead outweigh benefit. > So, this patchset doesn't include it. I will attach prototype just for > a reference. It appears that this patchset is perhaps due a couple of touchups from Christoph's comments. I'll grab it as-is as I want to get an mmotm into linux-next tomorrow then vanish for a few days. -- 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