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 59287C54FDF for ; Thu, 30 Jul 2026 09:46:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 340056B00A1; Thu, 30 Jul 2026 05:46:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2F0A16B00A5; Thu, 30 Jul 2026 05:46:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 16A6B6B00A6; Thu, 30 Jul 2026 05:46:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id DC4876B00A1 for ; Thu, 30 Jul 2026 05:46:24 -0400 (EDT) Received: from smtpin11.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 303D8A091E for ; Thu, 30 Jul 2026 09:46:24 +0000 (UTC) X-FDA: 85044962688.11.B52A2A0 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf09.hostedemail.com (Postfix) with ESMTP id 6CD58140002 for ; Thu, 30 Jul 2026 09:46:22 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=a8rlygMd; spf=pass (imf09.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1785404782; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=EDHJMwsw4RV+E0nCHPsR8cYc7dWvqN92OxTAgjiIye8=; b=PZNOE2cWh+onZ4la6mg7vOFeF6PoV7ktYqToZ5OHEXPDMwZvwgXxrGm2+E8n6JgZsTUZtO Yqynxt81ewhUpgBVGFfc0hGaAjimuaQ2K73cjDSTHYQ0geYp8/8ATTkI1Ozv+uwHGY3yXr H2FdMqsEoKFUrhHLmFoxXyC5J15Sdm0= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1785404782; b=tl+Mw7SAOHvighIwYdx5DskMAZJu0qlwpILtbFORP2mA5C0L0TSdVXOoyFaB71EKUEqWC9 N+MXRXIhG7oTVCjjFiPjtrHnOaeZIL+/0y5cRdjlsq+ud2D/ddibFnXe0OX+RG/c4Tqeds HcDclX5m9XJDatV4avwqMUzIdjNIhOU= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=a8rlygMd; spf=pass (imf09.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com; dmarc=pass (policy=none) header.from=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7C3241688; Thu, 30 Jul 2026 02:46:17 -0700 (PDT) Received: from cesw-amp-gbt-1s-m12830-01.blr.arm.com (cesw-amp-gbt-1s-m12830-01.blr.arm.com [10.164.195.33]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 4C0113F763; Thu, 30 Jul 2026 02:46:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785404781; bh=uvhE/tFT7Ldq689DpjcwVfkSIZmSWyixS8rBTZRMflU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a8rlygMdOo1mh6AIf2sT1e2i0T/CI+npPbtTQfKJyNeJatDW9LJB4vHRocMvy2+16 dKHdjeGuxDsBoJywpsA0aEnmZ1VdbVSAimGdHd25OpiYfJU+KcsgFAuLfQomAPYrAZ D0/yq0ujGZVHTvArQ8YtZNtoWf5dr2x5SRKxrMB0= From: Dev Jain To: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, muchun.song@linux.dev, osalvador@suse.de Cc: Dev Jain , riel@surriel.com, liam@infradead.org, vbabka@kernel.org, harry@kernel.org, jannh@google.com, lance.yang@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com Subject: [PATCH v4 1/5] mm/rmap: convert page -> folio for hwpoison checks Date: Thu, 30 Jul 2026 09:45:52 +0000 Message-ID: <20260730094559.418003-2-dev.jain@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260730094559.418003-1-dev.jain@arm.com> References: <20260730094559.418003-1-dev.jain@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 6CD58140002 X-Stat-Signature: 3jckudzzhwub11bby5gg96azc8u187rp X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1785404782-120390 X-HE-Meta: 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 7L3RvJAo F23E9tMePdG/jU6byPiT2XOMe1/b3cXGPYamptg7c8yMwhutzBb/9lYy6jQrD4jhCiJp0Dqy+ehv/DX9TsFg5GVfv/ag3vMrbMrfOiPFGoMTRs4mXIXL8B/ZB5WkvMeOoNjE0soXga2HEEYaOFwt+acIO6PfWjSBF/uwvg13wvb77K5xVYus6ojPrXBfvjbFG+6InmZ9L2VUWapwq4lCrjoPAxkAwIx45bOPtVXNlQJsmWcc4DFB6ATVxyhEB1h1yx0indpDvSKs1S0w= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: try_to_unmap() receives hugetlb folios only from the hwpoison path. hugetlb_update_hwpoison() sets the hugetlb folio's head-page hwpoison bit, and page_vma_mapped_walk() reports the hugetlb mapping at the head PFN, so the previous PageHWPoison(subpage) check happened to work for hugetlb. For non-hugetlb folios, unmap_poisoned_folio() currently rejects large folios before calling try_to_unmap(). Hence it is always the case that if try_to_unmap_one() handles an hwpoisoned folio, then the head page is marked with the poison bit. Therefore, convert the poisoned subpage checks to folio_test_hwpoison(). No functional change intended, except that, while at it, convert VM_BUG_* to VM_WARN_*. Reviewed-by: Lorenzo Stoakes (ARM) Acked-by: David Hildenbrand (Arm) Signed-off-by: Dev Jain --- mm/rmap.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index e854679553b9..77be9fcffa99 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -2122,10 +2122,11 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, bool anon = folio_test_anon(folio); /* - * The try_to_unmap() is only passed a hugetlb page - * in the case where the hugetlb page is poisoned. + * The try_to_unmap() is only passed a hugetlb folio + * in the case where the hugetlb folio contains a + * poisoned page. */ - VM_BUG_ON_PAGE(!PageHWPoison(subpage), subpage); + VM_WARN_ON_FOLIO(!folio_test_hwpoison(folio), folio); /* * huge_pmd_unshare may unmap an entire PMD page. * There is no way of knowing exactly which PMDs may @@ -2204,7 +2205,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, /* Update high watermark before we lower rss */ update_hiwater_rss(mm); - if (PageHWPoison(subpage) && (flags & TTU_HWPOISON)) { + /* unmap_poisoned_folio() only refs order-0 or hugetlb folios */ + if (folio_test_hwpoison(folio) && (flags & TTU_HWPOISON)) { pteval = swp_entry_to_pte(make_hwpoison_entry(subpage)); if (folio_test_hugetlb(folio)) { hugetlb_count_sub(folio_nr_pages(folio), mm); -- 2.43.0