From patchwork Wed Nov 15 13:27:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13456693 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 28DC5C531B2 for ; Wed, 15 Nov 2023 13:29:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=PH8EX3AR4F3dPly0vk9wP880Tvu+A8sFb6YAW7LkZCY=; b=aqdrrGTbixqpV8 O36prWBIn+iklARleN6cYbLcgy8B6TbbgJVA05JgiXF7wXBfgXqrAWlqAo3U5JlwdIciGhLWlI7Ni e1udgxTBdI+o7UtGOls3qDum8dgdevOVOs+wc9+/JfNA2Pe2xo8mLPLdiS4YqjIcmWogvG219fHlr xJ1Z7vzjpTRG10OaL1l7XankBkc93Uv4Y2EG8fAlQSGCqAyRg5RtLovfklwBoR8eQukAWN3BhvNjU V55jIDJY2yRU3DLSI7LcKVIVX9siaFbB6lneVDbUcFfkdivR/moal7UrBvanKLPcdvKr1bd+v1iN7 7SEogVb8uugNaiZs4zqA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r3FwV-000sBz-1V; Wed, 15 Nov 2023 13:28:31 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r3FwM-000s3N-2c for linux-arm-kernel@lists.infradead.org; Wed, 15 Nov 2023 13:28:25 +0000 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 E9C04DA7; Wed, 15 Nov 2023 05:29:07 -0800 (PST) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7A2383F7B4; Wed, 15 Nov 2023 05:28:19 -0800 (PST) From: Ryan Roberts To: Andrew Morton , Matthew Wilcox , Yin Fengwei , David Hildenbrand , Yu Zhao , Catalin Marinas , Anshuman Khandual , Yang Shi , "Huang, Ying" , Zi Yan , Luis Chamberlain , Itaru Kitayama , "Kirill A. Shutemov" , John Hubbard , David Rientjes , Vlastimil Babka , Hugh Dickins , Kefeng Wang Cc: Ryan Roberts , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v7 08/10] selftests/mm/khugepaged: Enlighten for small-sized THP Date: Wed, 15 Nov 2023 13:27:32 +0000 Message-Id: <20231115132734.931023-9-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231115132734.931023-1-ryan.roberts@arm.com> References: <20231115132734.931023-1-ryan.roberts@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231115_052822_986443_067AC6F9 X-CRM114-Status: GOOD ( 19.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The `collapse_max_ptes_none` test was previously failing when small-sized THP had enabled="always". The root cause is because the test faults in 1 page less than the threshold it set for collapsing. But when using small-sized THP we "over allocate" and therefore the threshold is passed, and collapse unexpectedly succeeds. Solve this by enlightening khugepaged selftest. Add a command line option to pass in the desired small-sized THP that should be used for all anonymous allocations. The harness will then explicitly configure small-sized THP as requested and modify the `collapse_max_ptes_none` test so that it faults in the threshold minus the number of pages in the configured small-sized THP. If no command line option is provided, default to order 0, as per previous behaviour. I chose to use an order in the command line interface, since this makes the interface agnostic of base page size, making it easier to invoke from run_vmtests.sh. Signed-off-by: Ryan Roberts --- tools/testing/selftests/mm/khugepaged.c | 48 +++++++++++++++++------ tools/testing/selftests/mm/run_vmtests.sh | 2 + 2 files changed, 39 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index 473ba095cffd..4d24f2eb158e 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -28,6 +28,7 @@ static unsigned long hpage_pmd_size; static unsigned long page_size; static int hpage_pmd_nr; +static int anon_order; #define PID_SMAPS "/proc/self/smaps" #define TEST_FILE "collapse_test_file" @@ -607,6 +608,11 @@ static bool is_tmpfs(struct mem_ops *ops) return ops == &__file_ops && finfo.type == VMA_SHMEM; } +static bool is_anon(struct mem_ops *ops) +{ + return ops == &__anon_ops; +} + static void alloc_at_fault(void) { struct thp_settings settings = *thp_current_settings(); @@ -673,6 +679,7 @@ static void collapse_max_ptes_none(struct collapse_context *c, struct mem_ops *o int max_ptes_none = hpage_pmd_nr / 2; struct thp_settings settings = *thp_current_settings(); void *p; + int fault_nr_pages = is_anon(ops) ? 1 << anon_order : 1; settings.khugepaged.max_ptes_none = max_ptes_none; thp_push_settings(&settings); @@ -686,10 +693,10 @@ static void collapse_max_ptes_none(struct collapse_context *c, struct mem_ops *o goto skip; } - ops->fault(p, 0, (hpage_pmd_nr - max_ptes_none - 1) * page_size); + ops->fault(p, 0, (hpage_pmd_nr - max_ptes_none - fault_nr_pages) * page_size); c->collapse("Maybe collapse with max_ptes_none exceeded", p, 1, ops, !c->enforce_pte_scan_limits); - validate_memory(p, 0, (hpage_pmd_nr - max_ptes_none - 1) * page_size); + validate_memory(p, 0, (hpage_pmd_nr - max_ptes_none - fault_nr_pages) * page_size); if (c->enforce_pte_scan_limits) { ops->fault(p, 0, (hpage_pmd_nr - max_ptes_none) * page_size); @@ -1076,7 +1083,7 @@ static void madvise_retracted_page_tables(struct collapse_context *c, static void usage(void) { - fprintf(stderr, "\nUsage: ./khugepaged [dir]\n\n"); + fprintf(stderr, "\nUsage: ./khugepaged [OPTIONS] [dir]\n\n"); fprintf(stderr, "\t\t: :\n"); fprintf(stderr, "\t\t: [all|khugepaged|madvise]\n"); fprintf(stderr, "\t\t: [all|anon|file|shmem]\n"); @@ -1085,15 +1092,34 @@ static void usage(void) fprintf(stderr, "\tCONFIG_READ_ONLY_THP_FOR_FS=y\n"); fprintf(stderr, "\n\tif [dir] is a (sub)directory of a tmpfs mount, tmpfs must be\n"); fprintf(stderr, "\tmounted with huge=madvise option for khugepaged tests to work\n"); + fprintf(stderr, "\n\tSupported Options:\n"); + fprintf(stderr, "\t\t-h: This help message.\n"); + fprintf(stderr, "\t\t-s: Small-sized THP size, expressed as page order.\n"); + fprintf(stderr, "\t\t Defaults to 0. Use this size for anon allocations.\n"); exit(1); } -static void parse_test_type(int argc, const char **argv) +static void parse_test_type(int argc, char **argv) { + int opt; char *buf; const char *token; - if (argc == 1) { + while ((opt = getopt(argc, argv, "s:h")) != -1) { + switch (opt) { + case 's': + anon_order = atoi(optarg); + break; + case 'h': + default: + usage(); + } + } + + argv += optind; + argc -= optind; + + if (argc == 0) { /* Backwards compatibility */ khugepaged_context = &__khugepaged_context; madvise_context = &__madvise_context; @@ -1101,7 +1127,7 @@ static void parse_test_type(int argc, const char **argv) return; } - buf = strdup(argv[1]); + buf = strdup(argv[0]); token = strsep(&buf, ":"); if (!strcmp(token, "all")) { @@ -1135,11 +1161,13 @@ static void parse_test_type(int argc, const char **argv) if (!file_ops) return; - if (argc != 3) + if (argc != 2) usage(); + + get_finfo(argv[1]); } -int main(int argc, const char **argv) +int main(int argc, char **argv) { int hpage_pmd_order; struct thp_settings default_settings = { @@ -1164,9 +1192,6 @@ int main(int argc, const char **argv) parse_test_type(argc, argv); - if (file_ops) - get_finfo(argv[2]); - setbuf(stdout, NULL); page_size = getpagesize(); @@ -1183,6 +1208,7 @@ int main(int argc, const char **argv) default_settings.khugepaged.max_ptes_shared = hpage_pmd_nr / 2; default_settings.khugepaged.pages_to_scan = hpage_pmd_nr * 8; default_settings.hugepages[hpage_pmd_order].enabled = THP_GLOBAL; + default_settings.hugepages[anon_order].enabled = THP_ALWAYS; save_settings(); thp_push_settings(&default_settings); diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 00757445278e..f3fa2238daef 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -359,6 +359,8 @@ CATEGORY="cow" run_test ./cow CATEGORY="thp" run_test ./khugepaged +CATEGORY="thp" run_test ./khugepaged -s 2 + CATEGORY="thp" run_test ./transhuge-stress -d 20 CATEGORY="thp" run_test ./split_huge_page_test