From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794226548; b=U8j8uzAbP/CJr8+VFmnGSmM5mcmlp+QA12C9t9oiLyicM15O8cQYencKjwPXfr7k2Ruy 6YMyWyKg2QPf5YE1svhLnbmer50YPi6toE8ICZ8HefElBxsG7C45dFwx7VYC5n+e9feFB eks2e3RfrogNGVAyfWLB29l0TGESUjN6e9QVFUvbRaIrd24xNHf/lhZYcMT/KV1uXXywQ WzZG29S9bNsglEEEqLIUFDYeqk7OaYmOuMZkE/F0zZn9UtXdfRPkeobY368DImFre6COI o+ZyYZT4BtsWs+fIoRNZUi+5N8cB88pvFeqfhRTQrZwCDoQyxBdjPoqtE9r5StQyRhQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794226548; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=EIhCSwebmDFcQc0LqZVR/7j2ncT1asAZ058Iwo/cnck=; b=ihyaP8G5OaGXe2NrtNt3WoukpWYC/5rPjdpU/Ruw8EISj32Q5H5AAlKxINJY+Tgtpqcb aeTdrCpHL56R90o4PnFOvzZ+eP0ehw3fxDazcOoY5U8OR9yBnM+PeEtPHEe58YuPtlheP OhHWnL0NxbeqDDkc7zzVW31K4UBKruAOLb7SOI1QvYN1DO8/3vDHwx5YcqSyVg9P0J0VI ZW8lqatbUqFhxOtbcuSWoueRuDZXMYVQl6O7ZgNOCLCax3o3sxddT5y5qIMHl2dkwuJMw 7S3XIOtQGrxdqq3dYPbBHvEeMngHt8e00yk+rf3XFx5SUA+ePCjG9rVqpYITNUEQ/SQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=FDx8aCcn; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 090D3606A325 for ; Mon, 9 Nov 2026 12:15:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=FDx8aCcn Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D5EF1F0089F; Mon, 9 Nov 2026 12:15:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794226547; bh=EIhCSwebmDFcQc0LqZVR/7j2ncT1asAZ058Iwo/cnck=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=FDx8aCcnP7gO/3MZ60mWa5FLcJdXxpLlf+ls+Ut66aE2mMZLswYpyfeP8pGvudqQV YBeGFMET/TshJW9EVjuZktAHfO+SI2cMHLK6OfjqdERbJoCIo6dW+2w7aH2AAiPMUJ mJZu+CQDePB1Elwxsx4BRcXI7r3ozgyPqBr6CTsJRZ5+NvF1NQ/RbW9Q5ZVdNz+K05 YIoDwOAz7CiHduy/oN+MwU/DBTEKUlYcsFYSOGynHd9Bx38Zq5bYIryS77cZSKzupw +AM1UEQIpwGS8etGtiXGJ4Lz+nxpNnvcld6Xf3hReMbdlHL61ZsH+Wao2Mi9IH1Tzt hhRorpD6u/sQA== Message-ID: <22e06030-92b8-43f7-96e2-ac3b168bf6fd@kernel.org> Date: Mon, 9 Nov 2026 13:15:39 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm/memory: drop PROCESS_PAGES_NON_PREEMPT_BATCH To: "Garg, Shivank" , "pfalcato@suse.de" Cc: "Rao, Bharata Bhasker" , "rppt@kernel.org" , "ankur.a.arora@oracle.com" , "vbabka@kernel.org" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "surenb@google.com" , "linux-mm@kvack.org" , "Salunke, Hrushikesh" , "liam@infradead.org" , "peterz@infradead.org" , "mhocko@suse.com" , "bp@alien8.de" , "ljs@kernel.org" , "Nayak, K Prateek" , "x86@kernel.org" References: <20261109-clear-pages-batch-v2-1-2e62c4f84f94@amd.com> <490893fe6ead90740ccd1fc1011004d03e49a27f.camel@amd.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 On 11/9/26 11:28, Garg, Shivank wrote: > On Mon, 2026-11-09 at 10:12 +0000, Pedro Falcato wrote: >>> >>> No functional change intended. >>> >>> Suggested-by: David Hildenbrand >>> Signed-off-by: Shivank Garg >> >> Reviewed-by: Pedro Falcato >> >> with a question below. >> >>> --- >>> This came up in review of the copy_mc_highpages() series [1]. Pedro >>> pointed out that most architecture run with full or lazy preempt, so mm >>> does not need to check the preemption model at runtime or batch the copy >>> > > >>> - >>> - might_sleep(); >>> + if (IS_ENABLED(CONFIG_PREEMPTION)) { >>> + clear_user_highpages(page, addr, nr_pages); >>> + return; >>> + } >>> >>> - for (i = 0; i < nr_pages; i += count) { >>> + for (i = 0; i < nr_pages; i++) { >>> cond_resched(); >>> - >>> - count = min(unit, nr_pages - i); >>> - clear_user_highpages(page + i, addr + i * PAGE_SIZE, count); >>> + clear_user_highpages(page + i, addr + i * PAGE_SIZE, 1); >> >> I think we can use clear_user_highpage() here. I don't know if that's >> necessarily desirable, but it would make this a little simpler. >> > > Sure, this makes sense. Will do this in next version. Makes sense. So I'll wait for the v3 :) -- Cheers, David