From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55910C433FE for ; Sat, 9 Oct 2021 00:41:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30C9E60FE8 for ; Sat, 9 Oct 2021 00:41:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244052AbhJIAnA (ORCPT ); Fri, 8 Oct 2021 20:43:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231809AbhJIAm7 (ORCPT ); Fri, 8 Oct 2021 20:42:59 -0400 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7671C061570 for ; Fri, 8 Oct 2021 17:41:03 -0700 (PDT) Received: by mail-pj1-x1035.google.com with SMTP id ls18so8779089pjb.3 for ; Fri, 08 Oct 2021 17:41:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=gbNbd7Wz3p2O73QmnnBxtoMhGaSnr/esB6d0N4BYdkI=; b=UdDACpcGI1OYHgzs7fn54lJkzb95zBJCcBzcGHNvaiBRASRQWD/q6MKpoOlieuDAdK VA9WjxdGPPpazXJ5w2HKmLOSjbaymw8QhO6irlr9R4gsvTVU/fe7HiEAMqSE2T7ADJMC zMZY6wOKabiw9VJcgpTGv5Zr6H21Kk/a6GLDIxTErukM6XU9wI/uZZkEl6U7V+UFK1J6 Fsz82c/1p8NApmcnC6qonAyfKv9KD8RCE71s/pS9T9UJZbudo6pE5GcnsBOi6s0H+jit RUd/oCfW4XV+Qs6aEuFb1X//FHvWnu+LiA+dVQyvFS506KDB5NIrRbmJ2Tf5w4tKAKTn bXHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=gbNbd7Wz3p2O73QmnnBxtoMhGaSnr/esB6d0N4BYdkI=; b=yis8hcr3puCrntIXzaUE56A3Y+IlgNIpg2MT0ov6t0eiEkgj7UcIOabS0hDt9h38hV dWvxGc/R+BVZAj07m4h/8yP92X+zLKKEWg5jo4uXK4/C/ZkYzp7kOiEfw8mlRrkbjsjh yU/LNKOLf0g0bukU/xFtSmsaXukip4UpiS8T3b7xl67C81/+LWYPkdmM1VTXJpjf6U63 6uLAKc5uWNFB3bMehKOY3H5j1wAJjHIgv0/HroqMucIhZP2wmbO6u2V0e+i6c55f8syo vbU0wpFXj3J8ix4W7tDWo/GuFTA2MAw1x60RIZ4VEmMt17ngkF30H31jHvFN10MaXff4 H8XQ== X-Gm-Message-State: AOAM532eH/ak/B7w8FGB7yr6q5cM41kx9y9QvClg0f7VKpD86fl/P1iL ohIPpFfFobD5xJBvUItmVEw= X-Google-Smtp-Source: ABdhPJyYwe7zdrfsKr5vEd8p4BqsNBWp4hcUbTNFi5nOi3lN9tZWD/JsDhtna7BolMR7mhRN0f8aZw== X-Received: by 2002:a17:902:b40a:b0:13d:cbcd:2e64 with SMTP id x10-20020a170902b40a00b0013dcbcd2e64mr12554348plr.18.1633740063356; Fri, 08 Oct 2021 17:41:03 -0700 (PDT) Received: from kvm.asia-northeast3-a.c.our-ratio-313919.internal (24.151.64.34.bc.googleusercontent.com. [34.64.151.24]) by smtp.gmail.com with ESMTPSA id lp9sm335253pjb.35.2021.10.08.17.41.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Oct 2021 17:41:03 -0700 (PDT) Date: Sat, 9 Oct 2021 00:40:58 +0000 From: Hyeonggon Yoo <42.hyeyoo@gmail.com> To: Matthew Wilcox Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka Subject: Re: [RFC] Some questions and an idea on SLUB/SLAB Message-ID: <20211009004058.GA4992@kvm.asia-northeast3-a.c.our-ratio-313919.internal> References: <20211009001903.GA3285@kvm.asia-northeast3-a.c.our-ratio-313919.internal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 09, 2021 at 01:33:43AM +0100, Matthew Wilcox wrote: > On Sat, Oct 09, 2021 at 12:19:03AM +0000, Hyeonggon Yoo wrote: > > - Is there a reason that SLUB does not implement cache coloring? > > it will help utilizing hardware cache. Especially in block layer, > > they are literally *squeezing* its performance now. > > Have you tried turning off cache colouring in SLAB and seeing if > performance changes? My impression is that it's useful for caches > with low associativity (direct mapped / 2-way / 4-way), but loses > its effectiveness for caches with higher associativity. For example, > my laptop: > > L1 Data Cache: 48KB, 12-way associative, 64 byte line size > L1 Instruction Cache: 32KB, 8-way associative, 64 byte line size > L2 Unified Cache: 1280KB, 20-way associative, 64 byte line size > L3 Unified Cache: 12288KB, 12-way associative, 64 byte line size > > I very much doubt that cache colouring is still useful for this machine. Hello Matthew, What benchmark did you use for test? - Hyeonggon