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 83F16CA5FC4 for ; Fri, 2 Oct 2026 09:57:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E38A26B00BC; Fri, 2 Oct 2026 05:57:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DEA2F6B00BD; Fri, 2 Oct 2026 05:57:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C64006B00BE; Fri, 2 Oct 2026 05:57:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 9DEF66B00BC for ; Fri, 2 Oct 2026 05:57:14 -0400 (EDT) Received: from smtpin26.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 2D5A81206E1 for ; Fri, 2 Oct 2026 09:57:14 +0000 (UTC) X-FDA: 85277233188.26.0BD76C4 Received: from mta0.migadu.com (out-165.mta0.migadu.com [91.218.175.165]) by imf27.hostedemail.com (Postfix) with ESMTP id 50A9B40006 for ; Fri, 2 Oct 2026 09:57:12 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="Yt3V/HcN"; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf27.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.165 as permitted sender) smtp.mailfrom=usama.arif@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1790935032; 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=cIyJpw1Wh9dOciT+jL3z38Hzg3YRBSVm2MwjdHgkrQg=; b=o4Yze1hYYX25uFPgsm0UL5vcM2PxewzskjLMQ9E7GX2agKG1L2ekdrNviGSIr2hXodsgwm mmLEXbfgX5zlKWj1it9ezkRiKhy8PNGda0TkEeBtbbEFO8bViPmCyalPtecqRm9AFRjlKj EZ55+oFyHd53wl9rQ5LqsEDJRg5xVA8= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="Yt3V/HcN"; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf27.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.165 as permitted sender) smtp.mailfrom=usama.arif@linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790935032; b=FLayzG2Gwuw6MEV5jgyQdNUn/CcJL0rJJeN3Oaby+10UanlSxuKGYX6po7l9PD/6jVsIgk nzV1YnrprGaipgGxc3ocsz+3CiKKwjY1mljUthcxvtYxwXtQclxARTKsSvDE1vVTgMTy+m DkVnkECTD0QY1sBLRdxTkg0rtoVQtc0= X-Envelope-To: linux-mm@kvack.org DKIM-Signature: a=rsa-sha256; bh=O3Mn4KnTxiYaTlhEiHGB+/12dl1tDr6TCxd6G0YbQtw=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790935031; v=1; x=1791539831; b=Yt3V/HcNbmcUwemCHOSvedDAbZZPykz2HBT8iGsDw6wpQkgc76n4u5oeY9f34TWwL6LIi4iy fTV5+hX1goo+Dp1QnOoM7lqLcccilIBDdA5zTR378xVaNZfh1qSdkVEV9XDG85Ky/IyvypGJPia dlZOHJ/w3+a/V50IANYe814g= X-Envelope-To: linux-mm@kvack.org Received: by mta10.migadu.com with ESMTPS id 32c8d113bd9f3403; Fri, 02 Oct 2026 09:57:10 +0000 X-Mizu-Trace-ID: 32c8d113bd9f3403 X-Migadu-Flow: FLOW_OUT From: Usama Arif To: Andrew Morton , david@kernel.org, chrisl@kernel.org, kasong@tencent.com, ljs@kernel.org, ziy@nvidia.com, linux-mm@kvack.org Cc: ying.huang@linux.alibaba.com, Baoquan He , willy@infradead.org, youngjun.park@lge.com, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, alex@ghiti.fr, kas@kernel.org, baohua@kernel.org, dev.jain@arm.com, baolin.wang@linux.alibaba.com, Nico Pache , Liam R. Howlett , ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com, yosry@kernel.org, qi.zheng@linux.dev, luizcap@redhat.com, kernel-team@meta.com, Usama Arif Subject: [PATCH v8 21/30] mm/madvise: skip PMD swap entries for MADV_COLD and MADV_PAGEOUT Date: Fri, 2 Oct 2026 02:52:35 -0700 Message-ID: <20261002095503.3585565-22-usama.arif@linux.dev> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261002095503.3585565-1-usama.arif@linux.dev> References: <20261002095503.3585565-1-usama.arif@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: obgmeokm88ikaoukdqro4wdoq4orgw43 X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 50A9B40006 X-HE-Tag: 1790935032-399687 X-HE-Meta: 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 suWfbhNF p+UiizqgLeAo4Z/KDuRsR7nYeyQGfuf8XfFBc7C1WGjNipONye30sGHzLnQIYpjC7B/Z4YIwM+xDhT483njNg9LC6wWhnHMd6HcJMfeaoqvapVdvIGrE50UJAmGEhE2X5yDJHRV7+lEK3Pd7S+tLSrBwDjslToLvwz27sO7vRjhRlOfjMTWofSFaOqsTqRzlxDTsa4EvwAAEYZIcIX0AXtbB3YEwwGjc/3OkZnHYSrAnqOlSfNRh6Mo8I4JS3QjicdG7Qk0zLgrLjAz/DEx7ObD5dxg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: A swapped-out THP has no resident folio to deactivate or reclaim, which is also the conclusion the PTE path reaches when it walks the swap entries and skips every one. madvise_cold_or_pageout_pte_range() gets there the long way round: pmd_trans_huge() is false for a PMD swap entry, so it falls out of the huge branch and tries to map a PTE table that a non-present PMD does not have. The entry can also appear after that first, lockless test, so re-check under the PMD lock; otherwise a PMD that turned into a swap entry while pmd_trans_huge_lock() was being taken trips the VM_WARN_ON_ONCE() that expects a migration or device-private entry. Signed-off-by: Usama Arif --- mm/madvise.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/mm/madvise.c b/mm/madvise.c index 70acb39b8b3dd..d3b5ed7e3cffb 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -385,6 +385,15 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, !can_do_file_pageout(vma); #ifdef CONFIG_TRANSPARENT_HUGEPAGE + /* + * Swapped-out THPs have no resident folio to deactivate or reclaim. + * Avoid descending into or splitting a PMD swap entry. + */ + if (pmd_is_swap_entry(*pmd)) { + walk->action = ACTION_CONTINUE; + return 0; + } + if (pmd_trans_huge(*pmd)) { pmd_t orig_pmd; unsigned long next = pmd_addr_end(addr, end); @@ -395,6 +404,9 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, return 0; orig_pmd = *pmd; + if (pmd_is_swap_entry(orig_pmd)) + goto huge_unlock; + if (unlikely(!pmd_present(orig_pmd))) { VM_WARN_ON_ONCE(!pmd_is_migration_entry(orig_pmd) && !pmd_is_device_private_entry(orig_pmd)); -- 2.53.0-Meta