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 CBE4AC021B1 for ; Thu, 20 Feb 2025 11:52:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 60D13280225; Thu, 20 Feb 2025 06:52:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5BD2D280220; Thu, 20 Feb 2025 06:52:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 43692280225; Thu, 20 Feb 2025 06:52:07 -0500 (EST) 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 2621B280220 for ; Thu, 20 Feb 2025 06:52:07 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 42F5250EBB for ; Thu, 20 Feb 2025 11:51:51 +0000 (UTC) X-FDA: 83140158822.08.6E34C74 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf08.hostedemail.com (Postfix) with ESMTP id A880D16000A for ; Thu, 20 Feb 2025 11:51:48 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=MtMJjsbR; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf08.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=1740052308; a=rsa-sha256; cv=none; b=SeRZnUDTed6pmUllfTS46tgKItgcU7gKoZZQly4R1+bELabj3XsqYWEFzstIgipDO/paJ4 H7ZGlsyVdBnpaklgS2zPafehqRs2ujq/Fs3ytOx6C1z4WQ+5g8OK/AJ6uARUDwZF6X2RfH 53f84s83Nq4aWHJtljfbmK4GrSHIGgU= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=MtMJjsbR; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf08.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=1740052308; 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=mBr0SgtnHCYiFsBcWQ6weYZTbRdO1rbmjW4f7Sy3Ft8=; b=xNnmNsCVaNufm9iHKb88DifHCQszX7XOBjXo+TK894IS8m1zC3BThlLPJ+OL4cpWDnZLSF t4yIBLC5omrr8Ej6nak+htTQS7u8WdgU0CDFGFzz8UCB+SRzwOKIjMP2vFVumxi7a6sFkD j4d1GSjHh/hrbdS52PJeoeOUtT2f7ns= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740052308; 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=mBr0SgtnHCYiFsBcWQ6weYZTbRdO1rbmjW4f7Sy3Ft8=; b=MtMJjsbR+7BXWiKOTkmZUGQTloXLahl3hMbMtY/PiWoCaYAhjP941s4EOpdwLV72tOs8uq zJElksTDb8AK+ulhnp6z4d2EMYj0LjVKQGkKFNcfIexktjFnahVMAmVeijVQq8T1tixlgb g5/eWmIvsx24QEBLtVQWLwNt6R3AsOg= 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-616-Kj4Jhvx2Nk2J9XW-QYuEhw-1; Thu, 20 Feb 2025 06:51:47 -0500 X-MC-Unique: Kj4Jhvx2Nk2J9XW-QYuEhw-1 X-Mimecast-MFC-AGG-ID: Kj4Jhvx2Nk2J9XW-QYuEhw_1740052306 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-43998ec3733so4105075e9.2 for ; Thu, 20 Feb 2025 03:51:46 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740052306; x=1740657106; 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=mBr0SgtnHCYiFsBcWQ6weYZTbRdO1rbmjW4f7Sy3Ft8=; b=wsuiHYPPNgIN4+HwikMKGBIqbbBEN9cv7JzD4WdHozy7XO0JWsWQirD1oqHW6fmg2r yEnDKXnCqVO36Yr9fzCBsB/Ex7MK12jkuRqcGVSONxptd8TW8iT+g/V1VE3q+UxtXBdX VCnY3FGEQMHHzaa3k5H+HaVebgCi7QnanOXb5icfBzaGVw2vOPct1VIy0dXfepUo/C5I ZnyPWZ++5hxnHUabNR56+atNLkTmPaXNGWdAbUvN6xPHKumL1oDJaK7HqVskRFnsWuzi TsPUjUUMYf+KC5D+dHkSnxlPuQocokaRTEIHbVx8d+Esiahxmc+eqzgO4K/4XFQuMP15 UC8w== X-Forwarded-Encrypted: i=1; AJvYcCVw7nAxt7gxQGv2GUaJ4FR5A+S61hDMxKesOB+64gjEvqu6I+EWRYWvlRHY17Rr/vhthsWZyAtpEQ==@kvack.org X-Gm-Message-State: AOJu0YxNgtzJXOBd1QIpi95mni/18HpzKGSBnXumem95e4f3p5EG8fHe yWokZ4pDP4IVHeuHmOrI2C93SIm3C7zqB+KMh5OeNPgcVA9HOQkQhDeUYnbUFc68bElHqjKE5rN LUzVX9ON3HVT9VtjLQ3pp4gKyatF5jjPBDOEpA3R+Wr5LkRCm+1ps462tFZM= X-Gm-Gg: ASbGncuFTgM2NxdUdED1XC9jq/jNQe6RtSVcJ5zr2yYBuVZgiH4/0lmqAi2bZ+BOMMj /QMiu2FgFVaTgduUhIZrV/DgblkLHv3IbJd0F3hZhdq/STAWHI+80xxNX12wn8aCAr1DrFrcupy ADyKyyRiX6PtstSGcKHwuLQNISIMMWh1xvCDow+hV33n/XKw1BW9ptcAh1VqDXq/naJxkUl14uk FiyLozJ4vTJ8fZUwfNrTerI8/uCQCHNH3VbqmMtr4OX6khEtPnzs9EBVE4kVUSXL2XbVe05+q80 7K+v+ZeRLxCVWqbPjVr/xzJ620mzmDnUmD5+nx7+ZBph9WcFuAwgrISXosSwwraWReypiNw60cW Ar61HA/iHb30ilw8VYP6DhvrIrQdrHg== X-Received: by 2002:a05:600c:548b:b0:439:9a40:a9ff with SMTP id 5b1f17b1804b1-4399a40ac3cmr57546505e9.1.1740052305587; Thu, 20 Feb 2025 03:51:45 -0800 (PST) X-Google-Smtp-Source: AGHT+IE3Q1vBWLy8jITcTBIhMHZsv8pvY8WalvXMgoplaUinz3S7uxyqUT+2Vn++NdI0bj3eRlaAoQ== X-Received: by 2002:a05:600c:548b:b0:439:9a40:a9ff with SMTP id 5b1f17b1804b1-4399a40ac3cmr57546305e9.1.1740052305138; Thu, 20 Feb 2025 03:51:45 -0800 (PST) Received: from ?IPV6:2003:cb:c706:2000:e44c:bc46:d8d3:be5? (p200300cbc7062000e44cbc46d8d30be5.dip0.t-ipconnect.de. [2003:cb:c706:2000:e44c:bc46:d8d3:be5]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-43985c50397sm113532355e9.0.2025.02.20.03.51.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 20 Feb 2025 03:51:43 -0800 (PST) Message-ID: Date: Thu, 20 Feb 2025 12:51:41 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 19/20] fs/dax: Properly refcount fs dax pages To: Alistair Popple Cc: akpm@linux-foundation.org, dan.j.williams@intel.com, linux-mm@kvack.org, Alison Schofield , lina@asahilina.net, zhang.lyra@gmail.com, gerald.schaefer@linux.ibm.com, vishal.l.verma@intel.com, dave.jiang@intel.com, logang@deltatee.com, bhelgaas@google.com, jack@suse.cz, jgg@ziepe.ca, catalin.marinas@arm.com, will@kernel.org, mpe@ellerman.id.au, npiggin@gmail.com, dave.hansen@linux.intel.com, ira.weiny@intel.com, willy@infradead.org, djwong@kernel.org, tytso@mit.edu, linmiaohe@huawei.com, peterx@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, jhubbard@nvidia.com, hch@lst.de, david@fromorbit.com, chenhuacai@kernel.org, kernel@xen0n.name, loongarch@lists.linux.dev References: 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: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: AGSBlqefAp3vgzQPR9QVXF4PmLkpGDKVVaGZovmC6Vw_1740052306 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: A880D16000A X-Rspamd-Server: rspam12 X-Stat-Signature: 7ggzpp46bm4df1t95wocodakf47saebp X-HE-Tag: 1740052308-638657 X-HE-Meta: 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 18TtYc4E 7blKvLHrSXCY6XXYjsruPqi6PF4+tufw0ogCmfDrKiraCQ0YgwBlpH4bcPuzic3W+F/XzHIk16jsGJ5oaPBno26I9y1gqwQ4Aj+LPWq1s9xZUe8wDgnpa0uf+CKaq+ympHdkcu0u/NvuDQZwaLWzbTuGUGFytdEc9Ky8F7OXkoBHOMxlE8a9gJ6iDmhbLa7aXT0lvYKjrsVjJY6ExsdnRIMQUaaKDSyiiKiSu3hbFRngwRRtjF/HXKspgIOle+WyKrh8wBLnJ5G7i2gwn/Bd2G1pCj1KY8x26ioTqULPKFa5D0DULGaY3bzQKd7ZeTTbpNDC8S53D2EDPxrMAj5/nfMZ6sUH+z63yk7MWqXktc3/4jFHuGs0o96yDKvwEAIwFubV4qrl5dFPGVnPyLP3oQflmlQ9tbJ/aUKCtvIjXatUe28qFflrlsd74wh4viIYF24Du8ygvbM5lyTKW39vrUaACUg== 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: >>> -static inline unsigned long dax_folio_share_put(struct folio *folio) >>> +static inline unsigned long dax_folio_put(struct folio *folio) >>> { >>> - return --folio->page.share; >>> + unsigned long ref; >>> + int order, i; >>> + >>> + if (!dax_folio_is_shared(folio)) >>> + ref = 0; >>> + else >>> + ref = --folio->share; >>> + >> >> out of interest, what synchronizes access to folio->share? > > Actually that's an excellent question as I hadn't looked too closely at this > given I wasn't changing the overall flow with regards to synchronization, merely > representation of the "shared" state. So I don't have a good answer for you off > the top of my head - Dan maybe you can shed some light here? Not that I understand what that dax-shared thing is or does, but the non-atomic update on a folio_put path looked "surprising". >>> diff --git a/include/linux/dax.h b/include/linux/dax.h >>> index 2333c30..dcc9fcd 100644 >>> --- a/include/linux/dax.h >>> +++ b/include/linux/dax.h >>> @@ -209,7 +209,7 @@ int dax_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, >> >> [...] >> >>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >>> index d189826..1a0d6a8 100644 >>> --- a/mm/huge_memory.c >>> +++ b/mm/huge_memory.c >>> @@ -2225,7 +2225,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, >>> tlb->fullmm); >>> arch_check_zapped_pmd(vma, orig_pmd); >>> tlb_remove_pmd_tlb_entry(tlb, pmd, addr); >>> - if (vma_is_special_huge(vma)) { >>> + if (!vma_is_dax(vma) && vma_is_special_huge(vma)) { >> >> I wonder if we actually want to remove the vma_is_dax() check from >> vma_is_special_huge(), and instead add it to the remaining callers of >> vma_is_special_huge() that still need it -- if any need it. >> >> Did we sanity-check which callers of vma_is_special_huge() still need it? Is >> there still reason to have that DAX check in vma_is_special_huge()? > > If by "we" you mean "me" then yes :) There are still a few callers of it, mainly > for page splitting. Heh, "you or any of the reviewers" :) So IIUC, the existing users still need the DAX check I assume (until that part is cleaned up, below). > >> But vma_is_special_huge() is rather confusing from me ... the whole >> vma_is_special_huge() thing should probably be removed. That's a cleanup for >> another day, though. > > But after double checking I have come to the same conclusion as you - it should > be removed. I will add that to my ever growing clean-up series that can go on > top of this one. Nice! -- Cheers, David / dhildenb