Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932334AbWABIhe (ORCPT ); Mon, 2 Jan 2006 03:37:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932335AbWABIhe (ORCPT ); Mon, 2 Jan 2006 03:37:34 -0500 Received: from nproxy.gmail.com ([64.233.182.201]:59589 "EHLO nproxy.gmail.com") by vger.kernel.org with ESMTP id S932334AbWABIhd convert rfc822-to-8bit (ORCPT ); Mon, 2 Jan 2006 03:37:33 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=Cuoy2RjPosZTe1Ss7ayRabwd6iTpNdTwbx9Yi7l6ifkmZMSOzCDqCeOdfuaax2EogatBYz12AR1M5bfbzlyvONd39Mz5W6rhY6nKKc0/X8Hco0v7F53KHSv+vzUtqYebrxaSFnvQA+lxTxKGSBSvcEYV4TrQibRtE+e3rBdGrEs= Message-ID: <84144f020601020037n7af7ac54l74cdbe602372c7f@mail.gmail.com> Date: Mon, 2 Jan 2006 10:37:31 +0200 From: Pekka Enberg To: Andreas Kleen Subject: Re: [POLL] SLAB : Are the 32 and 192 bytes caches really usefull on x86_64 machines ? Cc: Denis Vlasenko , Eric Dumazet , linux-kernel@vger.kernel.org In-Reply-To: <3186311.1135792635763.SLOX.WebMail.wwwrun@imap-dhs.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <7vbqzadgmt.fsf@assigned-by-dhcp.cox.net> <43A91C57.20102@cosmosbay.com> <200512281032.15460.vda@ilport.com.ua> <200512281054.26703.vda@ilport.com.ua> <3186311.1135792635763.SLOX.WebMail.wwwrun@imap-dhs.suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 734 Lines: 16 On 12/28/05, Andreas Kleen wrote: > I remember the original slab paper from Bonwick actually mentioned that > power of two slabs are the worst choice for a malloc - but for some reason Linux > chose them anyways. Power of two sizes are bad because memory accesses tend to concentrate on the same cache lines but slab coloring should take care of that. So I don't think there's a problem with using power of twos for kmalloc() caches. Pekka - 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/