From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Weinberger Subject: Re: [RFC PATCH v2 02/11] slab: add private memory allocator header for arch/lib Date: Fri, 17 Apr 2015 17:08:22 +0200 Message-ID: <553121E6.5000005@nod.at> References: <1427202642-1716-1-git-send-email-tazaki@sfc.wide.ad.jp> <1429263374-57517-1-git-send-email-tazaki@sfc.wide.ad.jp> <1429263374-57517-3-git-send-email-tazaki@sfc.wide.ad.jp> <55310033.1060108@nod.at> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from a.ns.miles-group.at ([95.130.255.143]:65277 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751560AbbDQPI3 (ORCPT ); Fri, 17 Apr 2015 11:08:29 -0400 In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Hajime Tazaki Cc: cl@linux.com, linux-arch@vger.kernel.org, arnd@arndb.de, corbet@lwn.net, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, netdev@vger.kernel.org, linux-mm@kvack.org, jdike@addtoit.com, rusty@rustcorp.com.au, upa@haeena.net, christoph.paasch@gmail.com, mathieu.lacage@gmail.com, libos-nuse@googlegroups.com Am 17.04.2015 um 17:02 schrieb Hajime Tazaki: > > Hi Christoph, Richard, > > At Fri, 17 Apr 2015 14:44:35 +0200, > Richard Weinberger wrote: >> >> Am 17.04.2015 um 14:17 schrieb Christoph Lameter: >>> On Fri, 17 Apr 2015, Hajime Tazaki wrote: >>> >>>> add header includion for CONFIG_LIB to wrap kmalloc and co. This will >>>> bring malloc(3) based allocator used by arch/lib. >>> >>> Maybe add another allocator insteadl? SLLB which implements memory >>> management using malloc()? >> >> Yeah, that's a good idea. > > first, my bad, I should be more precise on the commit message. > > the patch with 04/11 patch is used _not_ only malloc(3) but > also any allocator registered by our entry API, lib_init(). > > for NUSE case, we use malloc(3) but for DCE (ns-3) case, we > use our own allocator, which manages the (virtual) process > running on network simulator. > > if these externally configurable memory allocator are point > of interest in Linux kernel, maybe adding another allocator > into mm/ is interesting but I'm not sure. what do you think ? This is the idea behind SLLB. > btw, what does stand for SLLB ? (just curious) SLUB is the unqueued SLAB and SLLB is the library SLAB. :D >> Hajime, another question, do you really want a malloc/free backend? >> I'm not a mm expert, but does malloc() behave exactly as the kernel >> counter parts? > > as stated above, A1) yes, we need our own allocator, and A2) > yes as NUSE proofed, it behaves fine. Okay. >> In UML we allocate a big file on the host side, mmap() it and give this mapping >> to the kernel as physical memory such that any kernel allocator can work with it. > > libos doesn't virtualize a physical memory but provide > allocator functions returning memory block on a request > instead. Makes sense. I thought maybe it can help you reducing the code footprint. Thanks, //richard