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 592C2D26D60 for ; Fri, 9 Jan 2026 15:08:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BFFD96B008C; Fri, 9 Jan 2026 10:08:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BD76E6B0092; Fri, 9 Jan 2026 10:08:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD9CB6B0093; Fri, 9 Jan 2026 10:08:13 -0500 (EST) 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 9AAF56B008C for ; Fri, 9 Jan 2026 10:08:13 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 6F23F1A9ABB for ; Fri, 9 Jan 2026 15:08:13 +0000 (UTC) X-FDA: 84312756066.19.92B9FEF Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf05.hostedemail.com (Postfix) with ESMTP id 93799100014 for ; Fri, 9 Jan 2026 15:08:11 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=D5A49i8X; spf=pass (imf05.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1767971291; 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=2O5PgS3h7rUMfW8zetc6lr+7DUQ51Nxsxl6VimhpPuw=; b=cRuCo96UmV7aKrnydAYu7QG8T797cffMTdJEP3vd+vCeSPR1p+7YMsfvXd3AsvEZw0MHYG 3AqsPevoRJUF2G/GrkoRFisaH7YlE85v2XW8K+FSmzLBuyq1toCd7XPDzvPjwe1bTqPDep KFVoql3XryGzQBqhG3ZvofgJAyG7NEE= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=D5A49i8X; spf=pass (imf05.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1767971291; a=rsa-sha256; cv=none; b=p+yxMM34HY8W8hmBRI3yLUc6bIDIE4+iqTfe5vNJoWfpxL57ltZhQci9RDDRPe+lCguWoh Wctos/OvrylDxRUTp6UVsb8BBf/7RzmC1UL3g7bSwqWzGLXoaTpohx5wPN/OjyE2VHgdho 8QrYuOWC/Q3d9tqxD9VkLkC131zKKgA= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 7CEBC42AC6; Fri, 9 Jan 2026 15:08:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1067FC4CEF1; Fri, 9 Jan 2026 15:07:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767971290; bh=3Z8L26dcTskZ3ZdCQN0iSI+dIODX6q9MdBtGUwgu/Fc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=D5A49i8XZ+WWgc3yo8WpoToMpiFiiYIORsD5kdhtfLHgOWLJ+teHa3YKmPfqvZQto EOjbH06xY/Y2D1tuKVkl4Bn9mfBj2pRUINZJHsmiBlwwDKMfmgPNBdydHY/WcoODaP hXTbfv9bYAipERXqMFeW7thazUf0MBtEe10dcKDUEhB49l5TpS6DuQJGLnLWIPw35L /A7EpMCyhB3OpiWJ4xcCGJauiqHLzHAPYo90gEXDJEGp6mJ/mQ/yOKD0hyaBuAIhmW 2g9u3gE5rzMBGVklkmAIGwRJV3u8nzhfd1IwpNssclwPUhgU0okSyNsciYIOrvSviH Q73z6sh0NFzwA== Message-ID: <1e123306-0efe-457f-953b-d4a27ce6bc60@kernel.org> Date: Fri, 9 Jan 2026 16:07:57 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 14/14] mm: Add basic tests for lazy_mmu To: Kevin Brodsky , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Alexander Gordeev , Andreas Larsson , Andrew Morton , Anshuman Khandual , Boris Ostrovsky , Borislav Petkov , Catalin Marinas , Christophe Leroy , Dave Hansen , "David S. Miller" , David Woodhouse , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Juergen Gross , "Liam R. Howlett" , Lorenzo Stoakes , Madhavan Srinivasan , Michael Ellerman , Michal Hocko , Mike Rapoport , Nicholas Piggin , Peter Zijlstra , "Ritesh Harjani (IBM)" , Ryan Roberts , Suren Baghdasaryan , Thomas Gleixner , Venkat Rao Bagalkote , Vlastimil Babka , Will Deacon , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org References: <20251215150323.2218608-1-kevin.brodsky@arm.com> <20251215150323.2218608-15-kevin.brodsky@arm.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAa2VybmVsLm9yZz7CwY0EEwEIADcWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCaKYhwAIbAwUJJlgIpAILCQQVCgkIAhYCAh4FAheAAAoJEE3eEPcA/4Naa5EP/3a1 9sgS9m7oiR0uenlj+C6kkIKlpWKRfGH/WvtFaHr/y06TKnWn6cMOZzJQ+8S39GOteyCCGADh 6ceBx1KPf6/AvMktnGETDTqZ0N9roR4/aEPSMt8kHu/GKR3gtPwzfosX2NgqXNmA7ErU4puf zica1DAmTvx44LOYjvBV24JQG99bZ5Bm2gTDjGXV15/X159CpS6Tc2e3KvYfnfRvezD+alhF XIym8OvvGMeo97BCHpX88pHVIfBg2g2JogR6f0PAJtHGYz6M/9YMxyUShJfo0Df1SOMAbU1Q Op0Ij4PlFCC64rovjH38ly0xfRZH37DZs6kP0jOj4QdExdaXcTILKJFIB3wWXWsqLbtJVgjR YhOrPokd6mDA3gAque7481KkpKM4JraOEELg8pF6eRb3KcAwPRekvf/nYVIbOVyT9lXD5mJn IZUY0LwZsFN0YhGhQJ8xronZy0A59faGBMuVnVb3oy2S0fO1y/r53IeUDTF1wCYF+fM5zo14 5L8mE1GsDJ7FNLj5eSDu/qdZIKqzfY0/l0SAUAAt5yYYejKuii4kfTyLDF/j4LyYZD1QzxLC MjQl36IEcmDTMznLf0/JvCHlxTYZsF0OjWWj1ATRMk41/Q+PX07XQlRCRcE13a8neEz3F6we 08oWh2DnC4AXKbP+kuD9ZP6+5+x1H1zEzsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCgh Cj/CA/lc/LMthqQ773gauB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseB fDXHA6m4B3mUTWo13nid0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts 6TZ+IrPOwT1hfB4WNC+X2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiu Qmt3yqrmN63V9wzaPhC+xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKB Tccu2AXJXWAE1Xjh6GOC8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvF FFyAS0Nk1q/7EChPcbRbhJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh 2YmnmLRTro6eZ/qYwWkCu8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRk F3TwgucpyPtcpmQtTkWSgDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0L LH63+BrrHasfJzxKXzqgrW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4v q7oFCPsOgwARAQABwsF8BBgBCAAmAhsMFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAmic2qsF CSZYCKEACgkQTd4Q9wD/g1oq0xAAsAnw/OmsERdtdwRfAMpC74/++2wh9RvVQ0x8xXvoGJwZ rk0Jmck1ABIM//5sWDo7eDHk1uEcc95pbP9XGU6ZgeiQeh06+0vRYILwDk8Q/y06TrTb1n4n 7FRwyskKU1UWnNW86lvWUJuGPABXjrkfL41RJttSJHF3M1C0u2BnM5VnDuPFQKzhRRktBMK4 GkWBvXlsHFhn8Ev0xvPE/G99RAg9ufNAxyq2lSzbUIwrY918KHlziBKwNyLoPn9kgHD3hRBa Yakz87WKUZd17ZnPMZiXriCWZxwPx7zs6cSAqcfcVucmdPiIlyG1K/HIk2LX63T6oO2Libzz 7/0i4+oIpvpK2X6zZ2cu0k2uNcEYm2xAb+xGmqwnPnHX/ac8lJEyzH3lh+pt2slI4VcPNnz+ vzYeBAS1S+VJc1pcJr3l7PRSQ4bv5sObZvezRdqEFB4tUIfSbDdEBCCvvEMBgoisDB8ceYxO cFAM8nBWrEmNU2vvIGJzjJ/NVYYIY0TgOc5bS9wh6jKHL2+chrfDW5neLJjY2x3snF8q7U9G EIbBfNHDlOV8SyhEjtX0DyKxQKioTYPOHcW9gdV5fhSz5tEv+ipqt4kIgWqBgzK8ePtDTqRM qZq457g1/SXSoSQi4jN+gsneqvlTJdzaEu1bJP0iv6ViVf15+qHuY5iojCz8fa0= In-Reply-To: <20251215150323.2218608-15-kevin.brodsky@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: pkj1etg5rydqtj49731bktr41p5pqm7x X-Rspam-User: X-Rspamd-Queue-Id: 93799100014 X-Rspamd-Server: rspam08 X-HE-Tag: 1767971291-294875 X-HE-Meta: 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 Sji85KFJ kAruY0vryi6BLXhhQBNsZ8G2kpfcNK1sIqSSivUvkGuRnvNl3+uD9V2sKHr5so1pYlDp8Ciozq3tbk6fAEeOHOVGXw1jZEUT0WWHRO8/mV0AOHA7+9+LEtyhGU2vzEaapc/Jq4q+GAJLpSNwLY/hAXFKxG/keIH8tAWi2n2Ak2gt3xVYzqmvj/RsKl1XuShxQhG30WG/h+B9y+MqZHVIluPDuYqOCKCAcI1WBs+Duf9spD/IGH1ylGta/KbWF7cKUeaJ2K7/5O4XBdcBz0tDbbLQnm8IVBByA3HxEThCbpx6QsRtlb8aC0P0E/DY5elZGCHjxQBsHarZDb/kWG2LJ9LsJZH21eunIl+ZiFf/lvxPsjcyYliZ0aDEImXs5enhRZ1Ns0ByxOTJV3X4A/P0soIdJ9Ls5w9S9byddfdeQFjo81E6uIfok30xoqs/HyUGVMkVQyoPPJWfy+dE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 12/15/25 16:03, Kevin Brodsky wrote: > Add basic KUnit tests for the generic aspects of the lazy MMU mode: > ensure that it appears active when it should, depending on how > enable/disable and pause/resume pairs are nested. > > Signed-off-by: Kevin Brodsky > --- > mm/Kconfig | 12 ++++++ > mm/Makefile | 1 + > mm/tests/lazy_mmu_mode_kunit.c | 71 ++++++++++++++++++++++++++++++++++ > 3 files changed, 84 insertions(+) > create mode 100644 mm/tests/lazy_mmu_mode_kunit.c > > diff --git a/mm/Kconfig b/mm/Kconfig > index 62073bd61544..ac48deb44884 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -1471,6 +1471,18 @@ config ARCH_HAS_LAZY_MMU_MODE > MMU-related architectural state to be deferred until the mode is > exited. See for details. > > +config LAZY_MMU_MODE_KUNIT_TEST > + tristate "KUnit tests for the lazy MMU mode" if !KUNIT_ALL_TESTS > + depends on ARCH_HAS_LAZY_MMU_MODE > + depends on KUNIT > + default KUNIT_ALL_TESTS > + help > + Enable this option to check that the lazy MMU mode interface behaves > + as expected. Only tests for the generic interface are included (not > + architecture-specific behaviours). > + > + If unsure, say N. > + > source "mm/damon/Kconfig" > > endmenu > diff --git a/mm/Makefile b/mm/Makefile > index 2d0570a16e5b..9175f8cc6565 100644 > --- a/mm/Makefile > +++ b/mm/Makefile > @@ -147,3 +147,4 @@ obj-$(CONFIG_SHRINKER_DEBUG) += shrinker_debug.o > obj-$(CONFIG_EXECMEM) += execmem.o > obj-$(CONFIG_TMPFS_QUOTA) += shmem_quota.o > obj-$(CONFIG_PT_RECLAIM) += pt_reclaim.o > +obj-$(CONFIG_LAZY_MMU_MODE_KUNIT_TEST) += tests/lazy_mmu_mode_kunit.o > diff --git a/mm/tests/lazy_mmu_mode_kunit.c b/mm/tests/lazy_mmu_mode_kunit.c > new file mode 100644 > index 000000000000..2720eb995714 > --- /dev/null > +++ b/mm/tests/lazy_mmu_mode_kunit.c > @@ -0,0 +1,71 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +#include > +#include > + > +static void expect_not_active(struct kunit *test) > +{ > + KUNIT_EXPECT_FALSE(test, is_lazy_mmu_mode_active()); > +} > + > +static void expect_active(struct kunit *test) > +{ > + KUNIT_EXPECT_TRUE(test, is_lazy_mmu_mode_active()); > +} > + > +static void lazy_mmu_mode_active(struct kunit *test) > +{ > + expect_not_active(test); > + > + lazy_mmu_mode_enable(); > + expect_active(test); > + > + { > + /* Nested section */ > + lazy_mmu_mode_enable(); > + expect_active(test); > + > + lazy_mmu_mode_disable(); > + expect_active(test); > + } > + > + { > + /* Paused section */ > + lazy_mmu_mode_pause(); > + expect_not_active(test); > + > + { > + /* No effect (paused) */ > + lazy_mmu_mode_enable(); > + expect_not_active(test); > + > + lazy_mmu_mode_disable(); > + expect_not_active(test); > + > + lazy_mmu_mode_pause(); > + expect_not_active(test); > + > + lazy_mmu_mode_resume(); > + expect_not_active(test); > + } > + > + lazy_mmu_mode_resume(); > + expect_active(test); > + } > + > + lazy_mmu_mode_disable(); > + expect_not_active(test); > +} > + > +static struct kunit_case lazy_mmu_mode_test_cases[] = { > + KUNIT_CASE(lazy_mmu_mode_active), > + {} > +}; > + > +static struct kunit_suite lazy_mmu_mode_test_suite = { > + .name = "lazy_mmu_mode", > + .test_cases = lazy_mmu_mode_test_cases, > +}; > +kunit_test_suite(lazy_mmu_mode_test_suite); > + > +MODULE_DESCRIPTION("Tests for the lazy MMU mode"); > +MODULE_LICENSE("GPL"); Very nice test :) I think I prefer the EXPORT_SYMBOL_IF_KUNIT over disabling the test for PPC and over making lazy_mmu_mode_enable() non-inlined functions with an exported symbol. With the EXPORT_SYMBOL_IF_KUNIT stuff added Acked-by: David Hildenbrand (Red Hat) -- Cheers David