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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A8CD0CCD199 for ; Thu, 16 Oct 2025 21:10:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0C8718E0029; Thu, 16 Oct 2025 17:10:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 078BE8E0002; Thu, 16 Oct 2025 17:10:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ED0738E0029; Thu, 16 Oct 2025 17:10:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id D83C18E0002 for ; Thu, 16 Oct 2025 17:10:55 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id E4A5213AD9C for ; Thu, 16 Oct 2025 21:10:54 +0000 (UTC) X-FDA: 84005222028.27.62C4C51 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf21.hostedemail.com (Postfix) with ESMTP id 2AE991C000C for ; Thu, 16 Oct 2025 21:10:53 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=tMIsdnEG; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1760649053; 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=y4jFRnAOr0dg4XHLgf1Bmfn1kqWTnjJWnkTccVUl28U=; b=t7e0KSZDFxpV5U3ne28j4IUcyzBtv+OUKhysfXgVY216ewqGja6FvjuwJeADR0rJi5A5pQ SZBZVTOh/nvpE1jzNbWtErBg+vwUBdyBzpDuyTv68+c3csuaXFqm5txNa1B/Q2NLGkwV6z MNNMLwn/X+JSaBreCPh8aUK4dBx65BQ= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=tMIsdnEG; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1760649053; a=rsa-sha256; cv=none; b=HLrrWBRBxIod84yr/FGOGtkJujB8NaAz/gOARQpAbbUZY4Ju3eACnaKXcMPgmXNv5Z4If2 oOYN/1MpfTFn7oge1chm1rS1V5CmUW0RxNdmUmAFq826y0xIFsh6G0Ki4ro4tWOFmNY2Po olD5L0mI5WsZDSz3YJYnpups1Pxe2co= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 5DA00601A3; Thu, 16 Oct 2025 21:10:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6CB2C4CEF9; Thu, 16 Oct 2025 21:10:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1760649052; bh=udbT2Uw9/9LSBWgicmhF40FOD8d0WVUT4E1G6lBM7D8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=tMIsdnEGRjraIxkLmDAKIaWmx+XjAhRBRaST6evWWblC4vMC0GWML50Vu7nv0BUAe U9OfHdAjpPOxm+sI/F59U7Ri4Z11dPBS8P0KCfIDu1AqULQQ8iuyJCDym0s0kHY3Qw DZukSIZQ/RIEDjWUxnrlBS5TCp/At1ZtLaoJeefw= Date: Thu, 16 Oct 2025 14:10:51 -0700 From: Andrew Morton To: Kefeng Wang Cc: Lorenzo Stoakes , David Hildenbrand , , Zi Yan , Baolin Wang , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , , Sidhartha Kumar Subject: Re: [PATCH v3 1/3] mm: mprotect: always skip dma pinned folio in prot_numa_skip() Message-Id: <20251016141051.27e9ce8b47aa242724ae97a4@linux-foundation.org> In-Reply-To: <0d26ce96-2c59-47bd-a034-d7810ce6aa5f@huawei.com> References: <20251015123516.2703660-1-wangkefeng.wang@huawei.com> <20251015123516.2703660-2-wangkefeng.wang@huawei.com> <47f69b78-8141-42a6-b04a-f67ba0b90ee9@lucifer.local> <0d26ce96-2c59-47bd-a034-d7810ce6aa5f@huawei.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 2AE991C000C X-Stat-Signature: mpjcsmraqb7iemxtnu9e7sah4hwqqfnc X-Rspam-User: X-HE-Tag: 1760649053-809410 X-HE-Meta: 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 +En59OV3 uZSfvtB3cyUZAtKVu6e63HscjJMT0z0hM7jOzjnNuqwxoAAMwYiykqdoaEQo+knbmOSgmyhEBwvTSKFC2JQykXyayUDNto7S95tLAiFpnqatQglaXZCpgRXGpoAMEiJnSroRe5tgDd121w7UPNWP3f7zcNs9dAOBLF8Vi67R1Y+n/mOfjOyw6Mmc8vd17P5rWNXeERP71vHZErxZD7XA2PdzHZruppWASmG5P5YJPq3o6iHw+ZzVyq46+pTDsdLhnguBQYLV8TrgYdheq4JuJeidlvFKEGNBTPB+LHxX30bWtNxT2QiMMPXYwfFXudHx8vHgURV+2akn97iIKgJkHQLw2hg== 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 Thu, 16 Oct 2025 09:00:34 +0800 Kefeng Wang wrote: > On 2025/10/15 23:32, Lorenzo Stoakes wrote: > > On Wed, Oct 15, 2025 at 08:35:14PM +0800, Kefeng Wang wrote: > >> If the folio(even not CoW folio) is dma pinned, it can't be > >> migrated, so always skip pinned folio to avoid a waste of cycles > >> when folios migration. > > > > NIT: 'when folios migration' -> 'when folios are migrated'. > > > > Maybe worth saying 'due to elevated reference count?' > > > > Hope Andrew could help to update the changelog. > I changed it to this: : If the folio (even not CoW folio) is dma pinned, it can't be migrated : due to the elevated reference count. So always skip a pinned folio to : avoid wasting cycles when folios are migrated.