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 E024BCD98ED for ; Thu, 18 Jun 2026 09:34:45 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1966B6B00D2; Thu, 18 Jun 2026 05:34:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 16DFF6B00D3; Thu, 18 Jun 2026 05:34:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 085A26B00D4; Thu, 18 Jun 2026 05:34:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 7E30C6B00D2 for ; Thu, 18 Jun 2026 05:34:37 -0400 (EDT) Received: from smtpin29.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 2F64414043B for ; Thu, 18 Jun 2026 09:09:50 +0000 (UTC) X-FDA: 84892460940.29.B50F73A Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) by imf12.hostedemail.com (Postfix) with ESMTP id CF5614000B for ; Thu, 18 Jun 2026 09:09:46 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=iaVcoVSi; spf=pass (imf12.hostedemail.com: domain of lance.yang@linux.dev designates 91.218.175.172 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1781773788; 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=WKrBJr5QmN+p5FbcRlDp75b6qG882022YARGfpuKY7s=; b=oK1O1ntGHo/y9958/tO+ZN0Q1F75L24ELxY1zLsBQ106odK8Elo2wQf7SkNiupFvVHpcJs FlGX6GsoFIPfgH0gn+VJS068+Ii0pfdEhXzlGkoZhaBkJlv0nhP6g8RR3PeX73InsMyz9I iD/gvs7Ja+/Wp8/X1ahZiJPQO6ypKaU= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=iaVcoVSi; spf=pass (imf12.hostedemail.com: domain of lance.yang@linux.dev designates 91.218.175.172 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1781773788; b=M/imSCbbj5HfqWBY4nt5FpbyR5qjkyDHcWKMCwjMUeT5iDC06Q96BdEwEih+d7Qnomdpyo r0npfAhIH/JhGyRd0emD8KuWiEZjOCBntroQ1oWWBzvrUFsNteueATOGotclA52Xr0gXHX BOvR+NefTX7+9k6ITRkC9hnMAZErx6c= Message-ID: <0fe2a584-c633-4f82-8c47-d204e3b39a57@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1781773784; 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; bh=WKrBJr5QmN+p5FbcRlDp75b6qG882022YARGfpuKY7s=; b=iaVcoVSiDIAOGWJUuJNAp8Ahx07xCPBuz/Rn6y8sE6PY32pmlFgooAFFRZJLl1HreGsUMs NHy+Pf3tnl0QlBrwxn7rDoaiYpKoqBh6B6eag51TlKEAddnPbcx/CZr/YSR/arQESvRcdp TertYgNDaOYeIzia/R60F4s2Jttch0U= Date: Thu, 18 Jun 2026 17:09:28 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v4 02/12] mm/rmap: Add try_to_unmap_hugetlb_one Content-Language: en-US To: "David Hildenbrand (Arm)" , dev.jain@arm.com Cc: akpm@linux-foundation.org, ljs@kernel.org, chrisl@kernel.org, kasong@tencent.com, hughd@google.com, liam@infradead.org, riel@surriel.com, vbabka@kernel.org, harry@kernel.org, jannh@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, qi.zheng@linux.dev, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, youngjun.park@lge.com, baolin.wang@linux.alibaba.com, pfalcato@suse.de, ryan.roberts@arm.com, anshuman.khandual@arm.com References: <20260618074449.24974-1-lance.yang@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: CF5614000B X-Stat-Signature: fcgh7n4zpc99zmret58fdm798x9ipsib X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1781773786-506568 X-HE-Meta: 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 y3khOYV4 ne2DjvmG38Y86h1tjdh7eO9AaaCUrAJ0O1cWg/WpHdOLStf1qhNvWpQXpVAO1/eK4O+8nIYcKqotjY8e+iu+OJiF3j1uiejFCBLafkEB0UnMl4aEWNnyvXTpAnHEj/pV9Cf0Dpjg3tv6423+LSCIwuhsfOkUoFcntE5auMwv3g2uxe3O0ugTX1/NZItqQR2rPqCeAhmFoC146YKKvbIicZxUZZHPFzaWwjZfbCLooZqePNQdNrxm351MfYyIwxCUj0tUK Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2026/6/18 15:55, David Hildenbrand (Arm) wrote: >> return __rste_to_pte(pte_val(*ptep)); >> } >> >>>> + VM_WARN_ON(!pte_present(pteval)); >>>> + subpage = folio_page(folio, pte_pfn(pteval) - folio_pfn(folio)); >>> >>> No need for subpages. >> >> So plain ptep_get() can feed raw huge-entry bits into pte_pfn(), and the >> derived subpage can be wrong. > > Good question which impact that might have in practice? The subpage check can warn, but we still pass that subpage to make_hwpoison_entry(). So the hwpoison marker can end up with the wrong PFN? + subpage = folio_page(folio, pte_pfn(pteval) - folio_pfn(folio)); + VM_WARN_ON(folio_page(folio, 0) != subpage); [...] + pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));