From nobody Sun Jun 7 03:02:02 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 30BD83C09E7; Thu, 4 Jun 2026 05:53:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780552414; cv=none; b=DyadF10S4i5aU637RBMeBtxmgl0r2CxR3S/xoI9IIvdvchi7v3EMK9BOuIgM65FbSxsuVtLySBlUdKuRpAxZW1UkwbQpHu601tEAHIm17y86aOqyFPl03Ybs4mnE1xeimvM4RFjUpay/i1Pc94BEix08U3iSiAGao9ymkY0UBxc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780552414; c=relaxed/simple; bh=fr1ZIAKStZBd1psxptXiTd8a10xNZESCVeJoWx72PSo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XkbevvxICrzGKH1pjx4C+yMbxOIQWZuo4yMN8DG4qllyxa4G8R4Vt4icX3hy5rqujSGQEZ9MVWvw7v3RhcobGV9r4GLP6SIO9O0XwoAn7/6efPCVTtrOFCnn4+sj6vw5/TAEu7dEHk0ZgYFssriehtFvSFeSE43WwwEd0mgDPO8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=MSn4AOul; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="MSn4AOul" 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 8B4C53161; Wed, 3 Jun 2026 22:53:26 -0700 (PDT) Received: from cesw-amp-gbt-1s-m12830-01.blr.arm.com (cesw-amp-gbt-1s-m12830-01.blr.arm.com [10.164.195.31]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 690073F632; Wed, 3 Jun 2026 22:53:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780552411; bh=fr1ZIAKStZBd1psxptXiTd8a10xNZESCVeJoWx72PSo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MSn4AOuln+fZ2CVLJ6oX5bcQMRbDlPvZYZoMQ4eHlTUvTMK5Np1lmbcTk7jobKzHN 8ZftqXvWi5eO40qEL1SBCbcQqQZp8q8oAIv94LeQHM8Tev4qI9i3B0EsWM57JtrJmA QKoxqVtIl2Z5nGJo+44H7uVSc+cVItHrU+DAlwn0= From: Dev Jain To: akpm@linux-foundation.org, liam@infradead.org, ljs@kernel.org, jgg@ziepe.ca, leon@kernel.org, david@kernel.org, shuah@kernel.org Cc: Dev Jain , vbabka@kernel.org, jannh@google.com, pfalcato@suse.de, balbirs@nvidia.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-kselftest@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com, usama.arif@linux.dev, stable@vger.kernel.org, Oscar Salvador Subject: [PATCH v3 1/2] fs/proc/task_mmu: do not warn on seeing non-migration pmd entry Date: Thu, 4 Jun 2026 05:53:05 +0000 Message-ID: <20260604055308.1947679-2-dev.jain@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260604055308.1947679-1-dev.jain@arm.com> References: <20260604055308.1947679-1-dev.jain@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" pagemap_pmd_range_thp() warns if a non-present PMD is not a migration entry. This became false once device-private entries at the PMD level were added. Therefore, remove the stale migration-only assertion. Fixes: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone de= vice pages") Cc: stable@vger.kernel.org Reviewed-by: Balbir Singh Reviewed-by: Lorenzo Stoakes Tested-by: Lorenzo Stoakes Acked-by: David Hildenbrand (Arm) Reviewed-by: Oscar Salvador (SUSE) Signed-off-by: Dev Jain --- fs/proc/task_mmu.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 1e3a15bf46f4e..58938e62154d9 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -2129,7 +2129,6 @@ static int pagemap_pmd_range_thp(pmd_t *pmdp, unsigne= d long addr, flags |=3D PM_SOFT_DIRTY; if (pmd_swp_uffd_wp(pmd)) flags |=3D PM_UFFD_WP; - VM_WARN_ON_ONCE(!pmd_is_migration_entry(pmd)); page =3D softleaf_to_page(entry); } =20 --=20 2.43.0 From nobody Sun Jun 7 03:02:02 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3F103372EFF; Thu, 4 Jun 2026 05:53:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780552420; cv=none; b=mLCzlOjsTFrDWoVA2X7cICAn91OJGCg8NYZZvvKqWrYWthGLJvPFFpx0bWumvFc6c4aLUo9DgPWUSQkktFTqdWDuS32XOsNuenOHTVrsr4b+1QQ8sVRSWJS9UrcQKwr1503RR/uUfQ0UOTMAitnlUjG+UvHwOkBrb0KiScwY6hg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780552420; c=relaxed/simple; bh=4rGQj+ttPYrbAPiFOCuG9APk6p34IFP1qYSW6A86tnM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ovIjLrLtVwa5l3NjshuLiA59bceALgdq5QqahEE91mWTGKzUyIMmS0SS7WsmbjN99QOXTm8atxAqW5V02Q8CBQCTfKkMq9WsotJAxn20wE7LwcUgPWtda4k8pitA4IECd10h6ASX6lXcywDENpGtyWM7f6oznN5uOxexECPq2mI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=m8xTLEBX; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="m8xTLEBX" 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 A7BD1302F; Wed, 3 Jun 2026 22:53:33 -0700 (PDT) Received: from cesw-amp-gbt-1s-m12830-01.blr.arm.com (cesw-amp-gbt-1s-m12830-01.blr.arm.com [10.164.195.31]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1FA273F632; Wed, 3 Jun 2026 22:53:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780552418; bh=4rGQj+ttPYrbAPiFOCuG9APk6p34IFP1qYSW6A86tnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m8xTLEBXa3wzGDuPDeF6Vj8jVWgoOeLm71olZ/hYv2RKOQF8UTzE2+9HroqAVpxCQ y6XTey5VXwD85ArnHU+jKrOAYxECB1XedJLrOhNjCVxOTmqEi2RiXl/uBdoIUg/4GS JQLc5dxE2LZVeA1B+E0awCz+y4P4OtFVX5WCvfN4= From: Dev Jain To: akpm@linux-foundation.org, liam@infradead.org, ljs@kernel.org, jgg@ziepe.ca, leon@kernel.org, david@kernel.org, shuah@kernel.org Cc: Dev Jain , vbabka@kernel.org, jannh@google.com, pfalcato@suse.de, balbirs@nvidia.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-kselftest@vger.kernel.org, ryan.roberts@arm.com, anshuman.khandual@arm.com, usama.arif@linux.dev Subject: [PATCH v3 2/2] selftests/mm/hmm-tests: test pagemap reads of PMD device-private entries Date: Thu, 4 Jun 2026 05:53:06 +0000 Message-ID: <20260604055308.1947679-3-dev.jain@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260604055308.1947679-1-dev.jain@arm.com> References: <20260604055308.1947679-1-dev.jain@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" To cover pagemap paths scanning PMD entries, add assertions to check whether a device-private PMD entry has the correct pagemap information - the PM_SWAP bit must be on in the pagemap entry. Before that, we must assert through HMM_DMIRROR_SNAPSHOT snapshot that the leaf entry is at PMD level and not PTE level. Signed-off-by: Dev Jain Reviewed-by: Lorenzo Stoakes --- tools/testing/selftests/mm/hmm-tests.c | 34 ++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftes= ts/mm/hmm-tests.c index e1c8a679a4cf3..46e0c8c921c3d 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/tools/testing/selftests/mm/hmm-tests.c @@ -2276,8 +2276,11 @@ TEST_F(hmm, migrate_anon_huge_fault) unsigned long npages; unsigned long size; unsigned long i; + unsigned char *m; + uint64_t entry; void *old_ptr; void *map; + int pagemap_fd; int *ptr; int ret; =20 @@ -2300,8 +2303,6 @@ TEST_F(hmm, migrate_anon_huge_fault) =20 npages =3D size >> self->page_shift; map =3D (void *)ALIGN((uintptr_t)buffer->ptr, size); - ret =3D madvise(map, size, MADV_HUGEPAGE); - ASSERT_EQ(ret, 0); old_ptr =3D buffer->ptr; buffer->ptr =3D map; =20 @@ -2309,6 +2310,9 @@ TEST_F(hmm, migrate_anon_huge_fault) for (i =3D 0, ptr =3D buffer->ptr; i < size / sizeof(*ptr); ++i) ptr[i] =3D i; =20 + ret =3D madvise(map, size, MADV_COLLAPSE); + ASSERT_EQ(ret, 0); + /* Migrate memory to device. */ ret =3D hmm_migrate_sys_to_dev(self->fd, buffer, npages); ASSERT_EQ(ret, 0); @@ -2318,6 +2322,32 @@ TEST_F(hmm, migrate_anon_huge_fault) for (i =3D 0, ptr =3D buffer->mirror; i < size / sizeof(*ptr); ++i) ASSERT_EQ(ptr[i], i); =20 + if (!hmm_is_coherent_type(variant->device_number)) { + ret =3D hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, + buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + m =3D buffer->mirror; + for (i =3D 0; i < npages; ++i) + ASSERT_EQ(m[i], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL | + HMM_DMIRROR_PROT_WRITE | + HMM_DMIRROR_PROT_PMD); + + pagemap_fd =3D open("/proc/self/pagemap", O_RDONLY); + ASSERT_GE(pagemap_fd, 0); + + for (i =3D 0; i < npages; ++i) { + entry =3D pagemap_get_entry(pagemap_fd, + (char *)buffer->ptr + i * self->page_size); + + ASSERT_NE(entry & PM_SWAP, 0); + ASSERT_FALSE(PAGEMAP_PRESENT(entry)); + } + + close(pagemap_fd); + } + /* Fault pages back to system memory and check them. */ for (i =3D 0, ptr =3D buffer->ptr; i < size / sizeof(*ptr); ++i) ASSERT_EQ(ptr[i], i); --=20 2.43.0