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]) by smtp.lore.kernel.org (Postfix) with ESMTP id A38C6C2D0CD for ; Wed, 21 May 2025 15:40:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 474ED6B0085; Wed, 21 May 2025 11:40:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 426D16B0089; Wed, 21 May 2025 11:40:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2EE236B008A; Wed, 21 May 2025 11:40:17 -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 0FC6B6B0085 for ; Wed, 21 May 2025 11:40:17 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 76A3F140929 for ; Wed, 21 May 2025 15:40:16 +0000 (UTC) X-FDA: 83467326432.06.68BE401 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf17.hostedemail.com (Postfix) with ESMTP id D7E5940008 for ; Wed, 21 May 2025 15:40:13 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=aYhJeEYd; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf17.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1747842014; a=rsa-sha256; cv=none; b=QPId6qyamGL7sQCuLyEe5IubjWD24OXD6UAMo7EGLyhLKtISBe1O5AIE+iNu7p1ZSNW1wH voDhCY4Cj7zyPFKJotlta9kY4rgO2x/wCSc05Bp05CkL+HLwrltXYSHRW4z2IaxYZXkb6W T1Q653h7mPmWZCDNTtcbRt75r0Mh1WE= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=aYhJeEYd; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf17.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1747842014; 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=xsLGMafl9TLli4x/0rHFhu7b0Rej2k1hBcUbVvG/iQ8=; b=KyGJj9u0LK4z2sZa/8zyxVmw67d6KSKJJ0kg4deCjiuRp6zUlG5a5KWNtW5W80UV9W4yHT LjOPb6VgHx7bovrmoFfmkzo4ZJQM1QDH8eqgkVux7gRzrRQR/SYxrJ7kzaSkFEB2CF590B LRCU9ZBs7CdA2ythFTIKj+S/zINRdco= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1747842012; h=from:from: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:autocrypt:autocrypt; bh=xsLGMafl9TLli4x/0rHFhu7b0Rej2k1hBcUbVvG/iQ8=; b=aYhJeEYdZCzdBOebNlOt4NHD+fqu/HCogHPMUI1zKhButRGljfFskGdQEWx1hy3OVuHRKo fF1tYfuBQ34KqHbtMSIMQH8bXoFjkvfxq4bbB9n4c0ZPWlKKmrvfGGwjtmvNQZpkMhU3c3 2EagaBeiOjTqwjO78QyE53QHpWiLqbw= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-360-hE2HJLZPML2pIdx0t1b9XQ-1; Wed, 21 May 2025 11:40:10 -0400 X-MC-Unique: hE2HJLZPML2pIdx0t1b9XQ-1 X-Mimecast-MFC-AGG-ID: hE2HJLZPML2pIdx0t1b9XQ_1747842009 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-442dc6f0138so38639365e9.0 for ; Wed, 21 May 2025 08:40:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747842009; x=1748446809; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=xsLGMafl9TLli4x/0rHFhu7b0Rej2k1hBcUbVvG/iQ8=; b=AyKIZy/Q9DhkKqApSFy9ZPLGFrhComPggFoDssu1aZLlMQe53GBA3Wa3K62nGyCXxo JCYuEfxgZu/PbvjTpzF0Ua/qChSfQEP7E5OVfCbCZbnFVFWqIRpBBT0qIpKPHuSuaBqY YP70h/fCHnxzus1FLYBwS+A8NG4tjgolq2CDG+1H9rWGM/fB40g1ThWUh0mqdHiSbIbB gOEmANh1uPAZCZ/W2Z8AXRqanfQKkY29SMmKh+ygvsgVlwpaFUcqdhn0Y/tffHq+GXrY 9TrYDLRIqkMqKYMgwK6xq6evH51n1H0183VF8s8FPY9/KZXUCQYN3L+TZZamgtjX2kgI khcg== X-Forwarded-Encrypted: i=1; AJvYcCUnfioiu5bkER2RZU2WmYB1zD7iKHHw112wGyhqdKuZDJUng/0COPRrk+vo062QttZ2oz++FkoeLA==@kvack.org X-Gm-Message-State: AOJu0YxNrL7X6XBSt6+WW6B1KU34MmPJVI7xchVyK/8JO1wRh4BCoNB7 uMHzTXdeVRdcf9TuHyU64OtFL/Ix71JoPbx0SG2bzES8i6fNg3+61ZW6hXeVQCbqizUeesDFY5y 6gVUFUeBX+PfZOgtbFy7/5veib7xzaNha2gGkSGan/78uxiwLWTsV X-Gm-Gg: ASbGncu4L968485H11lbZrm+wTEC9OacMfeCutaXhvArp08Rn3x3Ch3/WagrKz23HxX 2D6bPXQ/lsjaFPCFsVKJ6smKApbMqFfSbsJ5wb6uUocokV1tg1f6OWb3wTHq1MNc6V1kGpoLZk7 8XRWjZQ09jY5hMhuKJisE1zk3aJt5XB5VKHOuPtmeixRc2pSVU45K9f5LsOoAgiBxVycAFithmB rzDW+Ch/TedYuTn4x4LpU8ERkDG+1YYgpdslkFzUjhxej++L73WZQvf2CguzERpJtOq4woUCHox jKZIz7r3E33wRTvc8OFh+mtYini1Wt5MimDF26p1amDCYdxxVNcTOEIeUvO74Q9I8tFynYWLnRa Cj+qENr4KwFTPoMfl68pHx44ua6kCFbJRFds0RN8= X-Received: by 2002:a05:600c:c8c:b0:43c:e467:d6ce with SMTP id 5b1f17b1804b1-442fd60cec5mr219804395e9.4.1747842009431; Wed, 21 May 2025 08:40:09 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFjNCF1eahpfitaO56mKWVDM5rQSqaa00w9A/gPv7i6POEGrYQiFRmtGHL69TaRQ3/tEaQ2Xw== X-Received: by 2002:a05:600c:c8c:b0:43c:e467:d6ce with SMTP id 5b1f17b1804b1-442fd60cec5mr219803925e9.4.1747842008993; Wed, 21 May 2025 08:40:08 -0700 (PDT) Received: from ?IPV6:2003:d8:2f25:9c00:e2c7:6eb5:8a51:1c60? (p200300d82f259c00e2c76eb58a511c60.dip0.t-ipconnect.de. [2003:d8:2f25:9c00:e2c7:6eb5:8a51:1c60]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-447f6f05581sm73492495e9.13.2025.05.21.08.40.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 May 2025 08:40:08 -0700 (PDT) Message-ID: <6ce8f663-2bcc-43a0-bbd8-71fc36005e86@redhat.com> Date: Wed, 21 May 2025 17:40:07 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9] mm/mempolicy: Weighted Interleave Auto-tuning To: Joshua Hahn Cc: gourry@gourry.net, akpm@linux-foundation.org, harry.yoo@oracle.com, ying.huang@linux.alibaba.com, honggyu.kim@sk.com, yunjeong.mun@sk.com, gregkh@linuxfoundation.org, rakie.kim@sk.com, rafael@kernel.org, lenb@kernel.org, dan.j.williams@intel.com, Jonathan.Cameron@huawei.com, dave.jiang@intel.com, horen.chuang@linux.dev, hannes@cmpxchg.org, osalvador@suse.de, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, kernel-team@meta.com References: <20250521153730.2196701-1-joshua.hahnjy@gmail.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20250521153730.2196701-1-joshua.hahnjy@gmail.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: K5PffpTx6BOvj29WVWBLiJVaLWdxtg6LnlVyXcWTUZA_1747842009 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: D7E5940008 X-Rspam-User: X-Stat-Signature: qbdtxy7fndireg9jn9hwjn447cz9fg8z X-HE-Tag: 1747842013-845162 X-HE-Meta: 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 3HUxuyHK 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 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 21.05.25 17:37, Joshua Hahn wrote: > On Wed, 21 May 2025 15:04:00 +0200 David Hildenbrand wrote: > >> On 20.05.25 16:12, Joshua Hahn wrote: > > [...snip...] > >> [...] >> >>> -static void iw_table_free(void) >>> +static void wi_state_free(void) >>> { >>> - u8 *old; >>> + struct weighted_interleave_state *old_wi_state; >>> >>> - mutex_lock(&iw_table_lock); >>> - old = rcu_dereference_protected(iw_table, >>> - lockdep_is_held(&iw_table_lock)); >>> - rcu_assign_pointer(iw_table, NULL); >>> - mutex_unlock(&iw_table_lock); >>> + mutex_lock(&wi_state_lock); >>> + >>> + old_wi_state = rcu_dereference_protected(wi_state, >>> + lockdep_is_held(&wi_state_lock)); >>> + if (!old_wi_state) { >>> + mutex_unlock(&wi_state_lock); >>> + goto out; >>> + } >>> >>> + rcu_assign_pointer(wi_state, NULL); >>> + mutex_unlock(&wi_state_lock); >> >> Just one nit: if written as: >> >> ... >> rcu_assign_pointer(wi_state, NULL); >> mutex_unlock(&wi_state_lock); >> >> old_wi_state = ... >> if (old_wi_state) { >> synchronize_rcu(); >> kfree(old_wi_state); >> } >> kfree(&wi_group->wi_kobj); >> >> You can easily avoid the goto. > > Ah I see, thank you for the suggestion! > I think we would have to move the "old_wi_state = ..." to be inside > the lock and before the rcu_assign_pointer since wi_state will be > NULL at that point if we do not, but other than that, I think this > is a great optimization over the version I have : -) > > I will send in a fix patch for this later as a cleanup patch, if > that sounds good with you! Sure, you can do a cleanup on top. -- Cheers, David / dhildenb