From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E23C9606A325 for ; Fri, 30 Oct 2026 14:37:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bF6R9279 Received: by kanga.kvack.org (Postfix) id 1528C6B00EF; Fri, 30 Oct 2026 10:37:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 105D16B05B3; Fri, 30 Oct 2026 10:37:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F34886B05B4; Fri, 30 Oct 2026 10:37:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id C662F6B00EF for ; Fri, 30 Oct 2026 10:37:52 -0400 (EDT) Received: from smtpin20.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 588521A06CF for ; Fri, 30 Oct 2026 14:37:52 +0000 (UTC) X-FDA: 85379546784.20.9DC91F9 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf19.hostedemail.com (Postfix) with ESMTP id 89E431A0007 for ; Fri, 30 Oct 2026 14:37:50 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=bF6R9279; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf19.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793371070; 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=uOYO1vBz1WqzK+TimXJTNpBfLu8OouAosUkHyHS7j4s=; b=2bZ8SxoKYz5bmyt1gwm5DRbwmwA6F4/kDZd4sc6yzAvmsF3E8P8cawLIVvNX/xpyxYm6rN bY1zco+DI2ebsV8iLk5MKaTz+ntJy/TCrFX54sh0mVmwlhpW2iG8XMtfPyPqy2aStEEFC9 EKaU3DRc9ep2vJOSSgS4QTxhk9hZrKg= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=bF6R9279; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf19.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793371070; b=3yG6jqk/MuOd451JvvgGG4mK/ebroNmRqOtrgUKK5qrysaClhSI9bloF90Y8KfvrJSoL+i PrJZNLP9v6MthmORiKf/BRzbNal0NRW8mpyqerHlKuTDH7Lb5BDVTxzN2h8qAN9JbQU+d0 CnkVnWpZCy4s5s1QBAMJJMhJT3AANDs= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id B297F439E5; Fri, 30 Oct 2026 14:37:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D2651F000C1; Fri, 30 Oct 2026 14:37:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793371069; bh=uOYO1vBz1WqzK+TimXJTNpBfLu8OouAosUkHyHS7j4s=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=bF6R9279b9c55sZunVufqLbJNHVpGKBm16I1N1EhD57KVbpTTV97cgxt+5quNJxhU AcBv2r5idRTx7z1d4FGqoqjMWGKBamCpKhDD815Qf7MjJH/RyQMi6wtbUEjI+Fsxfq 3UPWRaoTnrvjcppPpHLTtmK6MyDUEJGw7p1LycATDtjCtqj00PRuPJe0iUvWnJfNPO 4g8WVSEbre0QpmAQvYNAoIamCH34o/q4qyIKgFfupjeNVbxFYvnpmk8SydELkXK1Ad sH7yssGm1jBtjQi2I9rF/OMf/8/uxLDf3DBU8L+pn4Pd+PaTpTSitw09zSvNi70Mtb +e+8QcJWIXVYg== Message-ID: <9af1202f-9fae-4cca-904a-0ba00d7e726d@kernel.org> Date: Fri, 30 Oct 2026 15:37:29 +0100 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 00/47] mm: various (urgent?) fixes To: Chris Mason , Muhammad Usama Anjum , Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , "Lorenzo Stoakes (ARM)" , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , Matthew Wilcox , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Josef Bacik , stable@vger.kernel.org, Thadeu Lima de Souza Cascardo , Mani Tofigh , Samiullah Khawaja References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> <2f23dafc-43a5-47c9-a819-e696cda6fd44@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 89E431A0007 X-Stat-Signature: 1bsed8hyf8i88zi63jq4uo6eqcybjoxa X-Spam-Status: No, score=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1793371070-621349 X-HE-Meta: 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 VX0ciSzU /m/ClePBLmn/PUZaXQTfyhV7k5IfoPjVM4is906Eg5W3xsTzxs/IYkPBu+L/rnwrVbZX4dydmYgHMcY4yxxEyZ/Hn4YqtdGtKaY36UtmvG8iIUNipGAsZNIKlQH+UyWaFEKveVfWH2FNtXu9Qf8gOVjt3LRpfn/qj4j9sZFKeyiG6gZWdjbHnozLrP+Tvs0S8jnAYg8QjHY/JAGlYaiYL4rL7JQ8DsqxMJ1ioRAk9slugQPoHY85GsehY0EBNLDgcUHkfoqw3n1PlVXUvVhmv7kyjL81nMrwWb7f4lxBEFr1dbatFnSUr+1L9n4jMTlXO/Bh96Q1ckxFlzHpJ56JekSHQoxqtFQcMVg06pWuoJaWLCAlaSFCVthUjNocZmmh0oXPL Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/30/26 14:10, Chris Mason wrote: > > > On Fri, Oct 30, 2026, at 8:12 AM, Muhammad Usama Anjum wrote: >> On 30/10/2026 11:35 am, David Hildenbrand (Arm) wrote: >>> >>> >>> Thanks for the results. IIUC it's schbench that shows a possible regression. >>> >>> I would expect that no changes here really affect performance at all (neither >>> positively nor negatively). >>> >>> "mm/huge_memory: fix list corruption when deferred_split_scan() races with >>> deferred_split_folio()" fixes locking, but I wouldn't assume that this matters >>> at all for this benchmark. >>> >>> "fork: take mmap_lock before copying mm_struct" changes locking, but I also fail >>> to see how that would affect the benchmark. >>> >>> Maybe some code layout changes just affect some benchmark on some machines? >>> Because already seeing 10 improvements makes me wonder how that could possibly be. >>> >>> So I'll move forward with these fixes for now and see if we get more reports and >>> could identify actual problematic commits. >> >> Yes, these improvements/regression might be because of code movement and how it >> has affected the run time performance. Most importantly, these results show that >> there isn't any drastic affect on performance. These fixes are good to go. > > This schbench configuration is going to be really sensitive to process placement, and it > should be doing all of its memory allocations up front. I haven't done many schbench > runs on this type of hardware, but I'd agree this result shouldn't indicate a bigger lurking > regression anywhere. Thanks Chris and Usama! I'll respin a v3 shortly and get it into -next tomorrow (unless something really odd sticks out). -- Cheers, David