From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f49.google.com (mail-ej1-f49.google.com [209.85.218.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A93B83128C9 for ; Tue, 14 Oct 2025 12:23:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760444621; cv=none; b=n9y+iQBLp5Rfs7ys5sPysmtF2qFKHY5D4GG51Oqzb2PlcBfRve7JXvh+jPqK9ZDnohBzi0C2Kb+RSin/fPbvsVWgQd68iEygLH02yxz6BGPpvOHO94X1jZP5AuQIrGz7oOnrIurD3r1mA51+1X8MSzFfmrs8KsLsSU8Rm76x6C0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760444621; c=relaxed/simple; bh=trw3erKcBrmCOtT2DE5wAFGrqWHQObe9Vw1+YmbQxYY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Y8JjLniBbX2Cbx9CC82oCVwO0Z94Rfp98+MGl9F8cPVDWiir+aTJG6H+f1Sqe+/FsY0YZrtNB13LZHxOSI+wwGd2GMFOMWBXTyHBUg7IpK+2geNeAauFwAkCJsleMJI4qaYdoAbg6cvOMHsO7d/1s/Z2sLph+gOZfHdUcqqYQQo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Jc8MMyJ/; arc=none smtp.client-ip=209.85.218.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Jc8MMyJ/" Received: by mail-ej1-f49.google.com with SMTP id a640c23a62f3a-b3f5e0e2bf7so987279466b.3 for ; Tue, 14 Oct 2025 05:23:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1760444617; x=1761049417; darn=vger.kernel.org; h=user-agent:in-reply-to:content-disposition:mime-version:references :reply-to:message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=G4zpYT42/pWjG2wOiPoPN8UFfIlZHUseBg40P2GM6ks=; b=Jc8MMyJ/UeRfPsHTc2O/vVOKfChumvUkphUUc0Yt29Oc4uNhLrkKroREHOW007AgsF LQs8rB55fCRWUTPBk8goujK5NS4RW+tmYd8M9TjHH6J3iSPfVW3WFQuXGjSBfnYdxB97 SrivieCmlJgJ9YPSDxhUxGqZn+YFRE809SXXk4Azw2i7L9FDnCnFtdOuMLnLMCX9uqV4 oH/byr3DHo4EAjrCdVmzWFTvART0VChXazqVj3bjWtQzRb3V19NPhY42NcAmOU5MhtTb s/Ko0LDMTkhQWPW6lke8YNwYIRCHou14iZ7uq9BPw8OQ+Fc9eriOLY6D4gGnfDRePPSp HhrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760444617; x=1761049417; h=user-agent:in-reply-to:content-disposition:mime-version:references :reply-to:message-id:subject:cc:to:from:date:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=G4zpYT42/pWjG2wOiPoPN8UFfIlZHUseBg40P2GM6ks=; b=XMLAccbVXaVusNswYPn6X9A8qOXdrWlTKmrQeBayQ4p0I9Y8UfsjHPe6skKVsOM6f3 +DQKRTrWYe0lO21EbzwKB/Oecxzw9NaircV8A+ROR6HnibVwrfyOL8daYWK5JyHg5SOH OkHhcpt6r1rOH8eLxcnAld6SEhNuXQRo/HsPhPmLxAQj31sjFJVtvkQ9f6N8+o8/1OWk 37ekipOibn3COS/un8fYZEQ9EahyZvEiPcQObjV7iF2hOIrjdNeb5C0Bl9Wtef1mu0O1 nPIJYX+neYTDMh9EgvXF26nfqVjbxhkpJkIGH9fByOmdZSWRnRLUmcWvRzc2TUHgR4DV z8ng== X-Forwarded-Encrypted: i=1; AJvYcCUdSj/T8PKfgaC59sD0QqKaS9Mkoq3LQLYfJ/ZMb4ZX+pMbMprwSOxx6BzrUrMohUwwarq+eRvV@vger.kernel.org X-Gm-Message-State: AOJu0YxuHWC8XpSH0Bh6GZ0tqqyptZCLz1G0pAqtbUAlAmnPD7ewuCI7 6nWp3xH3xy9YYhk447ACol6rIJjJewXRRxT7M3jsJ3q+SAnEjK6TFVSTE9en5Q== X-Gm-Gg: ASbGnctVC56zW3pKnIjrLeFHqcUBuiDppR58LEAXWqcmDp53XMmmckXvY0XvX/DnazJ /Lxxp6ULxk98ehg19Ue0ZhqvFuKLvGK2V5CZ8n1JqnHFby941zTl5j9l8tsdk8mb5hOccvD3Akg DPggjStM0a0QhilmyWSEGOyRizJPy1hcwCgCW2GgCB5lYKUNNhdkOfbRfR7fzTq1E1AUXc7tWfn FEQp6BrEdAfVl4FSrV3Vr/2ELwA3suclCX9Q8GxzTxS2gMdwFJHKHu0nGpdcnTjwxa/+NhpDAta umggw5oLGE+7xkKQ9nRmiEPKfZZSJ6y0xMj4QcQj85L8RfyG043w2Orv1q+iGQ8tYTB6PNc+0K0 X70jnOMLAm3IuOCujhN2wFZ9C1n8Qil4wAUbxoiKnJd6Rwo/es0E= X-Google-Smtp-Source: AGHT+IHDOAfe4JNqhFSA9gUX7LcGwhfmUpTtqm0hZRNoZ9LOkkInOSpqZhVqzK5eUfW8u4Wf52cxuA== X-Received: by 2002:a17:906:730a:b0:b0b:20e5:89f6 with SMTP id a640c23a62f3a-b50ac5d07b5mr2495753366b.60.1760444616765; Tue, 14 Oct 2025 05:23:36 -0700 (PDT) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-63a52b715ffsm11262090a12.22.2025.10.14.05.23.35 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 14 Oct 2025 05:23:36 -0700 (PDT) Date: Tue, 14 Oct 2025 12:23:35 +0000 From: Wei Yang To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, Andrew Morton , "Matthew Wilcox (Oracle)" , Tejun Heo , Zefan Li , Johannes Weiner , Michal =?iso-8859-1?Q?Koutn=FD?= , Jonathan Corbet , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Muchun Song , "Liam R. Howlett" , Lorenzo Stoakes , Vlastimil Babka , Jann Horn Subject: Re: [PATCH v3 20/20] mm: stop maintaining the per-page mapcount of large folios (CONFIG_NO_PAGE_MAPCOUNT) Message-ID: <20251014122335.dpyk5advbkioojnm@master> Reply-To: Wei Yang References: <20250303163014.1128035-1-david@redhat.com> <20250303163014.1128035-21-david@redhat.com> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250303163014.1128035-21-david@redhat.com> User-Agent: NeoMutt/20170113 (1.7.2) On Mon, Mar 03, 2025 at 05:30:13PM +0100, David Hildenbrand wrote: [...] >@@ -1678,6 +1726,22 @@ static __always_inline void __folio_remove_rmap(struct folio *folio, > break; > case RMAP_LEVEL_PMD: > case RMAP_LEVEL_PUD: >+ if (IS_ENABLED(CONFIG_NO_PAGE_MAPCOUNT)) { >+ last = atomic_add_negative(-1, &folio->_entire_mapcount); >+ if (level == RMAP_LEVEL_PMD && last) >+ nr_pmdmapped = folio_large_nr_pages(folio); >+ nr = folio_dec_return_large_mapcount(folio, vma); >+ if (!nr) { >+ /* Now completely unmapped. */ >+ nr = folio_large_nr_pages(folio); >+ } else { >+ partially_mapped = last && >+ nr < folio_large_nr_pages(folio); Hi, David Do you think this is better to be? partially_mapped = last && nr < nr_pmdmapped; As commit 349994cf61e6 mentioned, we don't support partially mapped PUD-sized folio yet. Not sure what I missed here. >+ nr = 0; >+ } >+ break; >+ } >+ > folio_dec_large_mapcount(folio, vma); > last = atomic_add_negative(-1, &folio->_entire_mapcount); > if (last) { >-- >2.48.1 > -- Wei Yang Help you, Help me