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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3F94ECAAD4 for ; Wed, 31 Aug 2022 14:52:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230060AbiHaOw1 (ORCPT ); Wed, 31 Aug 2022 10:52:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbiHaOwZ (ORCPT ); Wed, 31 Aug 2022 10:52:25 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C616CC325 for ; Wed, 31 Aug 2022 07:52:24 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id y127so14668417pfy.5 for ; Wed, 31 Aug 2022 07:52:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc; bh=Gf8tbj4RpGeuppvSON/HSM0Glqk0yYviXDuhJFMb/GU=; b=cQxyBMvvozNYynus3zxZ3j6RzXSBCpn5FoAJ+nxKz3VHiS1lPZzxADwXlYRuG0lI3B iubXtay3v5e612hUHNMRi9pO3BoM7+V6nua4ccIirdwdAWV5GDmbXNB3aaP0GSgTpuWP nHW/4r7u39B3y081Hzdd0igqeAx9v0A/y+Tn0jf9CDsHJTsjTTvOjhaKnfYTW5kkLBrn KNgAj1LflkiZ/CvLjcjVtD6gnblQiNy2KksOanc3Da332hYVeyFKkr7EDZqsgSRqLj4T /auCOgZbeBvfyH8YPAadjtSdky6NohdNqcDfIs6cFywfY1K96K97eYQ7qGIxabWIC7/8 VmNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=Gf8tbj4RpGeuppvSON/HSM0Glqk0yYviXDuhJFMb/GU=; b=XKduJq2LcyXfak4c9mTFRIii7O52EntkErP+Pr9CFP75DEHc4op6aGfXvDGdHOJYsq uOrb2D74D0l33L6EEwgSKcHwcCPgR+Y82OQmcI+yb1UObIyncItfHYgkpAwuSnza2loH 50UkcY0U/G5oKb1ezdxx6eJ4nKiIt39ZjKDEN2FkC8mh1FwisqdA04Rt6d3boS0k/+c+ I25r7Veir2K9/WZmlzaIhegSxOn4CAxK4tCQcakSkjfDZh3drR4U0XmS6B3HmkfW4tr8 3ZfdsMZILyD0YQCOaExSXLZQ99F+rWB5bUwEf42gsS1FdHLVonjK+2Chr3cqGMqUyBjT cqGQ== X-Gm-Message-State: ACgBeo2cFc7YpCrUvh7iA9IGORrQWHy2em0zVdgrly+4KL+QUMehPVWV lUPYQIuyxVycPn457Uvpo5Q= X-Google-Smtp-Source: AA6agR7awV28A8GFlOqP8EMOm3gwrL/ylD9ZFMMEnI72iN/QFjWSAFyzuqanhGFK9yCQXMTjstNzFQ== X-Received: by 2002:a65:408b:0:b0:42a:55fb:60b0 with SMTP id t11-20020a65408b000000b0042a55fb60b0mr22418817pgp.431.1661957543649; Wed, 31 Aug 2022 07:52:23 -0700 (PDT) Received: from hyeyoo ([114.29.91.56]) by smtp.gmail.com with ESMTPSA id i63-20020a626d42000000b00537b8aa0a46sm11571093pfc.96.2022.08.31.07.52.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Aug 2022 07:52:22 -0700 (PDT) Date: Wed, 31 Aug 2022 23:52:15 +0900 From: Hyeonggon Yoo <42.hyeyoo@gmail.com> To: Feng Tang Cc: Andrew Morton , Vlastimil Babka , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Roman Gushchin , Dmitry Vyukov , Dave Hansen , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Robin Murphy , John Garry , Kefeng Wang Subject: Re: [PATCH v4 1/4] mm/slub: enable debugging memory wasting of kmalloc Message-ID: References: <20220829075618.69069-1-feng.tang@intel.com> <20220829075618.69069-2-feng.tang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220829075618.69069-2-feng.tang@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 29, 2022 at 03:56:15PM +0800, Feng Tang wrote: > kmalloc's API family is critical for mm, with one nature that it will > round up the request size to a fixed one (mostly power of 2). Say > when user requests memory for '2^n + 1' bytes, actually 2^(n+1) bytes > could be allocated, so in worst case, there is around 50% memory > space waste. > [...] > static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, > - unsigned long addr, struct kmem_cache_cpu *c) > + unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size) > { > void *freelist; > struct slab *slab; > @@ -3115,6 +3158,7 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, > > if (s->flags & SLAB_STORE_USER) > set_track(s, freelist, TRACK_ALLOC, addr); > + set_orig_size(s, freelist, orig_size); > > return freelist; > } > @@ -3140,6 +3184,8 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, > */ > if (s->flags & SLAB_STORE_USER) > set_track(s, freelist, TRACK_ALLOC, addr); > + set_orig_size(s, freelist, orig_size); > + > return freelist; > } Maybe we can move set_track() and set_orig_size() to after slab_post_alloc_hook(). something like alloc/free hooks for debugging caches? (and drop orig_size parameter.) Thanks! > > @@ -3182,7 +3228,7 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, > * pointer. > */ > static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, > - unsigned long addr, struct kmem_cache_cpu *c) > + unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size) > { > void *p; -- Thanks, Hyeonggon