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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C3D06CCD1BF for ; Fri, 24 Oct 2025 23:57:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A191D8E011E; Fri, 24 Oct 2025 19:57:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9F0388E0112; Fri, 24 Oct 2025 19:57:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 92CE78E011E; Fri, 24 Oct 2025 19:57:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 7DD318E0112 for ; Fri, 24 Oct 2025 19:57:33 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 31EBEBE810 for ; Fri, 24 Oct 2025 23:57:33 +0000 (UTC) X-FDA: 84034672386.05.5374248 Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) by imf15.hostedemail.com (Postfix) with ESMTP id 4E61BA000D for ; Fri, 24 Oct 2025 23:57:31 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=FZelkvxj; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf15.hostedemail.com: domain of alexei.starovoitov@gmail.com designates 209.85.221.43 as permitted sender) smtp.mailfrom=alexei.starovoitov@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1761350251; a=rsa-sha256; cv=none; b=8H0GOuyFYcywZdMW2ux8ZFaHeCR/5CvW43zNpddxuDzArNSZdnNACTqhzv+u839CJ1AKUo zOQgVZsFRpN8Okyn7Bkkci2BH5mSved7Zvo1Q903de5mThWuJhcqqMORQ1XKw0maprVZ9C Hwc+pqjIKfje/AoWPbueBKNouUBTVQ4= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=FZelkvxj; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf15.hostedemail.com: domain of alexei.starovoitov@gmail.com designates 209.85.221.43 as permitted sender) smtp.mailfrom=alexei.starovoitov@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1761350251; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=dNKLlMrwd1/HZexcmyJUATq+vFaKLMO+fNIoDoZR3Os=; b=LG7thPYyReA4pNf/oWUJ6H+6sUY2Dl56CGUltFfJe2lktk5eJB+KcNnse5IRDBDNdjQZ/Y 9c5p9iNWipxkn+zzHHbpnC0CFBdBkFlS9gAr9US0gJ3dV1jdm4DIGJnq3N1+pZ+sTy+3m7 DKiZRvF11y/WSsdv8YLJbiXoBfZLVvY= Received: by mail-wr1-f43.google.com with SMTP id ffacd0b85a97d-3ee130237a8so1807452f8f.0 for ; Fri, 24 Oct 2025 16:57:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1761350250; x=1761955050; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=dNKLlMrwd1/HZexcmyJUATq+vFaKLMO+fNIoDoZR3Os=; b=FZelkvxjlu66amJLrBLJZ5yHSc2B2s3t+CHr2AXXjRr0IlOPJxzgQbyDBMwt4+i6Lx IvyT8idoxqXTnmeRKX78iD9lf8mIQNQjUEpOnSA5pk7xEXtwbIPxFgjbA1PEwdN39/IF 6FoBHgloMSfQN/CDtDIWaSNF6PAE4ATUtHskGdy/o4XbXkptzYUdjiHb6pRWW2u+JYnD lYxUylYOYUaX2rgHkAPztziGc7iQIpqDHjQf406CyhJ2aQKODg3nbcJCpJRFXZZaLVRv sUSqE/h5c2p2WraMYnbWcO/kvIAPGGWY4NDXHrQOZWLQ2PCci02e4Y5xVGB4u/oPVZsY 9aYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761350250; x=1761955050; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=dNKLlMrwd1/HZexcmyJUATq+vFaKLMO+fNIoDoZR3Os=; b=aszKXBsC16MLs8aZNmJh9/9rlcWi+jixoLgtHPg/DspJP8RM98E4+6PCPsEfZmfe8E X3wVamnobosqiD1RsWdgzU3KwETn+ayOPEio/Os+m7P7Bn2RdhI6f0+V22nEGvj+NZXc UEm8pmTTNUCXFg3YvKZ3FHb+6J04sewy/Rn8NJAsg9YTdPUAi2PeVkcao7E6QfBf35DI ftORK+oBfXVir5nHotnfyyAYXMe9shqQvtmpb404gTjW6+630t7orzTIzB3qUXPxjhLi 4RgMkqgOQ2I7e6SqzUUK4KlByWI1BOewsxi5UQG6GWQ0ZQJgtxNcnjLLe/5ooPkI3YmX 4sKA== X-Forwarded-Encrypted: i=1; AJvYcCUFi1DdX7geKVt2giu8JIu/g4D6oyqUxKNSXrqPWJG60TOf4Q++JVDuZcmAeiwe3GuhylJl0h1O3A==@kvack.org X-Gm-Message-State: AOJu0Yys699pNJxeUC6iG3VF73BHYrKFPZVqeKBf5TVxV7NqwLr/oBOl 4y64hIZMkFCCyr0pmLSWeMzPViK/IRjZQRHSqcmhy6ZpWixZpJ5LE4h/M/KzA1ljlkBm3hTaXTy +VU8NkuugF5G31EMJAw2BF0xbxrrxqpI= X-Gm-Gg: ASbGncu3WPfP7j3fw0CjghJKUn5QOXgkhw7fju2f8+4B2B/gcNslUdG/3AZ0eAYiKud lsHADmyLXSBh+mov82eOqF2MgQPaholHVEQxluFnRZDUklVg27mnWr3MuaWeOdiFh3FPnKF+/Qo hkwrCV293MlLJxcVkZE3XLljqP1k33l9qp4CEBJqX3w8SeKY96/E6/uX3qG/rLEB8+f7DD+/+8c cCaXlO1ditWIVv4a4DiGnkGyItjXTzjqscmL9gDMDcK9RqwuYthPH3Tj49BNvhmWHUHkJG8boE3 HP1aeHj/Jt0oyJsxY+nAKK6XW/i7 X-Google-Smtp-Source: AGHT+IF8HoLxCsbxFn0Q05QHNEFaH5LN/KgcQUuwi/NFCX+hm+nzFT1ZjELINl1AgyfVOFTyiPf1ZTpt2LmAPKbOJ38= X-Received: by 2002:a5d:5f55:0:b0:427:5ed:296d with SMTP id ffacd0b85a97d-42990712615mr3163617f8f.28.1761350249591; Fri, 24 Oct 2025 16:57:29 -0700 (PDT) MIME-Version: 1.0 References: <20251023-sheaves-for-all-v1-0-6ffa2c9941c0@suse.cz> In-Reply-To: <20251023-sheaves-for-all-v1-0-6ffa2c9941c0@suse.cz> From: Alexei Starovoitov Date: Fri, 24 Oct 2025 16:57:18 -0700 X-Gm-Features: AWmQ_bltQWl9Zt65mlT3O0wfqqWroGd-22lI3adDJdCXk0hQ4ymeHmC7hV8Eb1Q Message-ID: Subject: Re: [PATCH RFC 00/19] slab: replace cpu (partial) slabs with sheaves To: Vlastimil Babka Cc: Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , Uladzislau Rezki , "Liam R. Howlett" , Suren Baghdasaryan , Sebastian Andrzej Siewior , Alexei Starovoitov , linux-mm , LKML , linux-rt-devel@lists.linux.dev, bpf , kasan-dev , Alexander Potapenko , Marco Elver , Dmitry Vyukov Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 4E61BA000D X-Stat-Signature: 8157kuipdt7kfakihc7miwucw5ky6b8x X-HE-Tag: 1761350251-517007 X-HE-Meta: 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 +eeFyzV3 FPyd8z96X49+VFoy23cVYKB4n9MIEohRuHnn/ssyTxuxE5HZcTJIDJlHXFVN0/EIBBpOluQhpQVl+tUXC+enBoFIL+E29s5+NVV62wAUAUpW1d5Qkck6ZUz0reBODcEkFiNWWGK1NHOmp+Nwdi19wY/JspiAnazYyRGmtKqbOUz5IeXlMHenSRGK9/5WNLA3XXjx0o9aQ1Zj5tqqyZzMIZ6WG0n3K/qMrhPVjqtkSfXrPCWH90xk7j6Nc0vy02pKj4onqYML3R5d99hk0wxR+gUAP+Nq+JxZ7a9cMWFqC3KMn0LNK8RDx17oH0zU2B4jF6hruPaldd45itpO/gXaMIKi05oRGtQcONYkHhzGG7bu5WlEONOpMz0PZa5vp+ETYdfc9RLiiNhz27uc= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Oct 23, 2025 at 6:53=E2=80=AFAM Vlastimil Babka wr= ote: > > Percpu sheaves caching was introduced as opt-in but the goal was to > eventually move all caches to them. This is the next step, enabling > sheaves for all caches (except the two bootstrap ones) and then removing > the per cpu (partial) slabs and lots of associated code. > > Besides (hopefully) improved performance, this removes the rather > complicated code related to the lockless fastpaths (using > this_cpu_try_cmpxchg128/64) and its complications with PREEMPT_RT or > kmalloc_nolock(). > > The lockless slab freelist+counters update operation using > try_cmpxchg128/64 remains and is crucial for freeing remote NUMA objects > without repeating the "alien" array flushing of SLUB, and to allow > flushing objects from sheaves to slabs mostly without the node > list_lock. > > This is the first RFC to get feedback. Biggest TODOs are: > > - cleanup of stat counters to fit the new scheme > - integration of rcu sheaves handling with kfree_rcu batching The whole thing looks good, and imo these two are lower priority. > - performance evaluation The performance results will be the key. What kind of benchmarks do you have in mind?