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 A2803C43458 for ; Wed, 8 Jul 2026 12:21:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 89F726B0095; Wed, 8 Jul 2026 08:21:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 876866B0098; Wed, 8 Jul 2026 08:21:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 765AD6B0099; Wed, 8 Jul 2026 08:21:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 4A8FE6B0095 for ; Wed, 8 Jul 2026 08:21:02 -0400 (EDT) Received: from smtpin29.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id BE99A166158 for ; Wed, 8 Jul 2026 12:21:01 +0000 (UTC) X-FDA: 84965518722.29.E8AD471 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) by imf14.hostedemail.com (Postfix) with ESMTP id 1F9D610000C for ; Wed, 8 Jul 2026 12:20:59 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=CtaObjrd; spf=pass (imf14.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.186 as permitted sender) smtp.mailfrom=usama.arif@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=1783513260; 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=2Fn1VOZHGCiDZaYCm98LuGj7iddLxiK8xDaGMUh3nqA=; b=KCwxhrzZSmgk8b0ixMnUulvEMAotBkcihm7g0nYwOH3zfF1GU4k71SCKSpxz1GF0nB82oD oGxyCgi937/NnkdGtwaF8C21o7zW22De0L3jJhqugs+2gZz+baga6PupqBOvo08pZoLT5x UiH+XaGob0n5259xqk5CsetIlaGvyig= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=CtaObjrd; spf=pass (imf14.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.186 as permitted sender) smtp.mailfrom=usama.arif@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=1783513260; b=wVtU75DsgScoLsD8WUinFDuKRWrlprcd4R5kt3CX+Y56tJ7VwC1xJudvOcf8gsDl40hJya VEcHVYC1vQ0k+YehqXxHF1higEAm93VH/2J5ZrQJNrj2ElXJA2vN4Bg5I3YwTTaF03CHz1 ni5LRJLRS8j0LAd0uL0hZyAi4SVdeHs= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1783513257; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2Fn1VOZHGCiDZaYCm98LuGj7iddLxiK8xDaGMUh3nqA=; b=CtaObjrdR977XBk5Te7aEsP20O9ZZ1icNmNajWdyd2wpUY/OdU9o0CqFpIc2L3g1OKXtBF o5Vy+Rv/QkfN+NdURZyX6kVlf1nGAIIzF4AmBh24KQVSICX6gerC569Cb0Etg4f3HmitjY +rF24lBH4avmkC6JF2hd2DODvXvECAc= From: Usama Arif To: Andrew Morton , apopple@nvidia.com, balbirs@nvidia.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, byungchul@sk.com, david@kernel.org, dev.jain@arm.com, gourry@gourry.net, jannh@google.com, joshua.hahnjy@gmail.com, lance.yang@linux.dev, liam@infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, matthew.brost@intel.com, npache@redhat.com, rakie.kim@sk.com, ryan.roberts@arm.com, usama.arif@linux.dev, vbabka@kernel.org, ying.huang@linux.alibaba.com, ziy@nvidia.com, shakeel.butt@linux.dev, hannes@cmpxchg.org Cc: sashiko-bot , stable@vger.kernel.org Subject: [PATCH v2 2/3] mm/madvise: skip device-private PMDs in cold and pageout walks Date: Wed, 8 Jul 2026 05:20:08 -0700 Message-ID: <20260708122040.861335-3-usama.arif@linux.dev> In-Reply-To: <20260708122040.861335-1-usama.arif@linux.dev> References: <20260708122040.861335-1-usama.arif@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 1F9D610000C X-Stat-Signature: up3jfxjjbrwmc81seo9gsp8ptfb3jacy X-HE-Tag: 1783513259-651116 X-HE-Meta: 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 d0It1vO5 C7p7Zjcmx1cKaPsTw29nTeTS5138ICyCtaVEnAHjX45V1LeLmGKvNfZ8OZO5VTmGNSxZze++uOF2tx4cuVYGNxX41lQeCNeGtqbfE/rf1fOWQXwhtMIqmwXl4jO4OYdjc8vj+ZsBm0uWF9aNzqfNxI+c8Hc65cmIV3NeOsGsw5II9twvgCXZbDvPCL2IzG4FN2gCn0QhY5x0Jb4+sdZ2Q138Bs0fzBDTS8J0ZFVfUQN00dDEOkyY/MtZ/n0nc4p1aKoOUL9f8TEnU4VEF9mr+c1EtHMUo3IelVODgbPWtVFwp/miz8KcBfDGNs3j3ufJmEq4lYn3sOLzKgn1n0id6uU+P/wyKz5588wTllFTXhPLbqMhsX2RWUUCfhTgGnFlCb88l9QvX74IvjmJ3xZGK2TOpjQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: madvise_cold_or_pageout_pte_range() takes pmd_trans_huge_lock(), whose pmd_is_huge() check returns true for a device-private PMD. The subsequent !pmd_present() branch has a VM_BUG_ON() asserting migration is the only allowed non-present case; a device-private PMD trips it. Allow device-private PMDs in that non-present assertion and continue to huge_unlock before calling pmd_folio(). This keeps the assertion for unexpected PMD softleafs while skipping device-private PMDs like other non-present PMDs in this path. Potential trigger: an HMM-based GPU driver races with madvise(MADV_COLD)/MADV_PAGEOUT: pmd_trans_huge(*pmd) reads true, then migrate_vma_pages() flips the PMD to a device-private entry before the PMD lock is acquired. Reported-by: sashiko-bot Link: https://sashiko.dev/#/patchset/20260703173903.3789516-1-usama.arif%40linux.dev?part=6 Fixes: 368076f52ebe ("mm/huge_memory: add device-private THP support to PMD operations") Cc: Reviewed-by: Joshua Hahn Reviewed-by: Zi Yan Reviewed-by: Balbir Singh Signed-off-by: Usama Arif --- mm/madvise.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/madvise.c b/mm/madvise.c index 9292f60b19aa..1065b5a84ea7 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -389,7 +389,8 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, if (unlikely(!pmd_present(orig_pmd))) { VM_BUG_ON(thp_migration_supported() && - !pmd_is_migration_entry(orig_pmd)); + !pmd_is_migration_entry(orig_pmd) && + !pmd_is_device_private_entry(orig_pmd)); goto huge_unlock; } -- 2.53.0-Meta