Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757575AbYCXRed (ORCPT ); Mon, 24 Mar 2008 13:34:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753220AbYCXReX (ORCPT ); Mon, 24 Mar 2008 13:34:23 -0400 Received: from rn-out-0910.google.com ([64.233.170.187]:64164 "EHLO rn-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752687AbYCXReW (ORCPT ); Mon, 24 Mar 2008 13:34:22 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=UeWflHOPkyxDUGy7zKC5gigr8PxJTe+ADfyoi/I5G8HgR3opUGsL1EWzeQJoOMvg++8ggZFkZn14OwAMnq4Zt4T9E+OKMudHEFYT8q23jn0OJMQQG2QERqK1fKp1Dx9yT1Dm3XLYTu8B2CAmFe1gCpKzDmTW7QU1wYJEXrGLctk= Message-ID: <4cefeab80803241034m6f62c01fq669129db9959f47f@mail.gmail.com> Date: Mon, 24 Mar 2008 23:04:18 +0530 From: "Nitin Gupta" To: "Peter Zijlstra" Subject: Re: [PATCH 3/6] compcache: TLSF Allocator interface Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <1206377777.6437.123.camel@lappy> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200803242034.24264.nitingupta910@gmail.com> <1206377777.6437.123.camel@lappy> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1638 Lines: 37 On Mon, Mar 24, 2008 at 10:26 PM, Peter Zijlstra wrote: > On Mon, 2008-03-24 at 20:34 +0530, Nitin Gupta wrote: > > Two Level Segregate Fit (TLSF) Allocator is used to allocate memory for > > variable size compressed pages. Its fast and gives low fragmentation. > > Following links give details on this allocator: > > - http://rtportal.upv.es/rtmalloc/files/tlsf_paper_spe_2007.pdf > > - http://code.google.com/p/compcache/wiki/TLSFAllocator > > > > This kernel port of TLSF (v2.3.2) introduces several changes but underlying > > algorithm remains the same. > > > > Changelog TLSF v2.3.2 vs this kernel port > > - Pool now dynamically expands/shrinks. > > It is collection of contiguous memory regions. > > - Changes to pool create interface as a result of above change. > > - Collect and export stats (/proc/tlsfinfo) > > - Cleanups: kernel coding style, added comments, macros -> static inline, etc. > > Can you explain why you need this allocator, why don't the current > kernel allocators work for you? > > kmalloc() allocates one of pre-defined sizes (as defined in kmalloc_sizes.h). This will surely cause severe fragmentation with these variable sized compressed pages. Whereas, TLSF maintains very fine grained size lists. In all the workloads I tested, it showed <5% fragmentation. Also, its very simple as just ~700 LOC. - Nitin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/