From patchwork Tue Jul 19 19:56:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Axel Rasmussen X-Patchwork-Id: 12922974 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]) by smtp.lore.kernel.org (Postfix) with ESMTP id C865BC43334 for ; Tue, 19 Jul 2022 19:56:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 64AA88E0002; Tue, 19 Jul 2022 15:56:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5FA048E0001; Tue, 19 Jul 2022 15:56:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4E8B88E0002; Tue, 19 Jul 2022 15:56:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 4019D8E0001 for ; Tue, 19 Jul 2022 15:56:41 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 17C77A037A for ; Tue, 19 Jul 2022 19:56:41 +0000 (UTC) X-FDA: 79704907002.11.E709272 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) by imf21.hostedemail.com (Postfix) with ESMTP id ADC3F1C0014 for ; Tue, 19 Jul 2022 19:56:40 +0000 (UTC) Received: by mail-yb1-f202.google.com with SMTP id a8-20020a25a188000000b0066839c45fe8so11636463ybi.17 for ; Tue, 19 Jul 2022 12:56:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=kfHTJgvI1xhbc2HV5Dg5HLOm6jC5g70kHqbkIkuEdDY=; b=eATFJJjY0r2Ckp5HyJYF7nbsKpNr/n+bnVWTBX/qKJPuAEJFHTGGCBZXyp9cXnxBjg Ca1+y0xLR0qoBqtrlrNHYULBzMXCsc8caFlMWYdtEt52PUQhmCcZQT9ESXfI1teZEuWa IWUlbVDzn15ayl5FiIOdT8aMilcfI1uMjS5UpC1ymoVTyAuboD3MgfK8/r3RKHzKZmKP 8m5pTgYtqjZZkBSc+eWfj3+JIt1hCkNiSZnJ7k/w+No27VJ2bcyRAaOz1ogd6Mrde2Rr +tyNsenOxNV9jPukEvgPal2QfI5GQaafFY21IscEco8k3Vd5LNcprxRmuTztwvxV115+ 2EZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=kfHTJgvI1xhbc2HV5Dg5HLOm6jC5g70kHqbkIkuEdDY=; b=ohkLYW0qeWdBTnM22E0BpTaQ15PLZOmSiEKl5OM99yGBroPEyQJcS8kWS/NvnU5Dz0 ekk/WW6I5k/LNB1VmrkKEYShMjrntcu6pln5aHwrvzI0fReNj5LVHavllF+uJ+rlSl6z jGnE+0XUsoUtlKPhJyHHEa99IWDTAbwCzyXajQT/hj1j7bGAt65iN9GFkT98hKOHbNNF Ww/RkXkunAOlITouDBqVCEbxbuNvamKZlGnl0fNXibuclF2i+SdnRwiPqQ8+S65pmdO3 ogY7yZrKP8gOmxoJLyt6H+ZWsFQFrS2Q+dzSJUof1HPd5wQ0ohLxoBHgF7xABtnAQVAg RfhQ== X-Gm-Message-State: AJIora/h10nQUVQop1+0HhcgEwF6IWGRgDbfGjVuS+9t3dBLJfEdpcct R2J2LyvDj+7ePDnlQDtTh9yBDHMkZstGoHtlS8G4 X-Google-Smtp-Source: AGRyM1vh6EyxVuVXbs2vKNFncUeOGmAA4GIWCwxEtu04z5gOe8ex1hyo5UKRpWnlw9uhvTBE62Bd9M97+L2VvA7rWmqs X-Received: from ajr0.svl.corp.google.com ([2620:15c:2d4:203:a065:9221:e40d:4fbe]) (user=axelrasmussen job=sendgmr) by 2002:a25:3b11:0:b0:66e:ccf2:76dc with SMTP id i17-20020a253b11000000b0066eccf276dcmr33549674yba.247.1658260600090; Tue, 19 Jul 2022 12:56:40 -0700 (PDT) Date: Tue, 19 Jul 2022 12:56:26 -0700 In-Reply-To: <20220719195628.3415852-1-axelrasmussen@google.com> Message-Id: <20220719195628.3415852-4-axelrasmussen@google.com> Mime-Version: 1.0 References: <20220719195628.3415852-1-axelrasmussen@google.com> X-Mailer: git-send-email 2.37.0.170.g444d1eabd0-goog Subject: [PATCH v4 3/5] userfaultfd: selftests: modify selftest to use /dev/userfaultfd From: Axel Rasmussen To: Alexander Viro , Andrew Morton , Dave Hansen , "Dmitry V . Levin" , Gleb Fotengauer-Malinovskiy , Hugh Dickins , Jan Kara , Jonathan Corbet , Mel Gorman , Mike Kravetz , Mike Rapoport , Nadav Amit , Peter Xu , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , zhangyi Cc: Axel Rasmussen , linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=eATFJJjY; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf21.hostedemail.com: domain of 3eAzXYg0KCAsl8pw2l3x533pyrzzrwp.nzxwty58-xxv6lnv.z2r@flex--axelrasmussen.bounces.google.com designates 209.85.219.202 as permitted sender) smtp.mailfrom=3eAzXYg0KCAsl8pw2l3x533pyrzzrwp.nzxwty58-xxv6lnv.z2r@flex--axelrasmussen.bounces.google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658260600; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=kfHTJgvI1xhbc2HV5Dg5HLOm6jC5g70kHqbkIkuEdDY=; b=WaCFF3leNDUlL40hWpgJ70zzDAUVyvObIUsykvq4DCwUvlsSxzB7Ts3NWDBpzt4tshFN0E mUT75Q4nbD/1vZ3fHcGPwYEzV8hobnC4ICl/D1nqXQcYa4Hq+KsBq0SHIAWvY37OykR/1X CKVvUzZm2lmFVWIS5DYLA3MTRmaEwV0= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658260600; a=rsa-sha256; cv=none; b=OfPS5Otlz9huII47b+4uZjy04gMMB0c9Sh2f7IHrwhPQZSYBnC8tn2pfkNWsgaUZJubzgv CLLZltjOgVDsezYpBxZXO1WkwOT34i4jZPuk2v+BDQidwc83qXZQ2Zc2MiUpZnqnFb34YM THOJl9PZXySTQwZV7R7+nC9azTuVe7I= X-Rspamd-Queue-Id: ADC3F1C0014 Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=eATFJJjY; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf21.hostedemail.com: domain of 3eAzXYg0KCAsl8pw2l3x533pyrzzrwp.nzxwty58-xxv6lnv.z2r@flex--axelrasmussen.bounces.google.com designates 209.85.219.202 as permitted sender) smtp.mailfrom=3eAzXYg0KCAsl8pw2l3x533pyrzzrwp.nzxwty58-xxv6lnv.z2r@flex--axelrasmussen.bounces.google.com X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: o8fsxyhsrbhug9737qyyj6ozn6hby95p X-HE-Tag: 1658260600-701820 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: We clearly want to ensure both userfaultfd(2) and /dev/userfaultfd keep working into the future, so just run the test twice, using each interface. Instead of always testing both userfaultfd(2) and /dev/userfaultfd, let the user choose which to test. As with other test features, change the behavior based on a new command line flag. Introduce the idea of "test mods", which are generic (not specific to a test type) modifications to the behavior of the test. This is sort of borrowed from this RFC patch series [1], but simplified a bit. The benefit is, in "typical" configurations this test is somewhat slow (say, 30sec or something). Testing both clearly doubles it, so it may not always be desirable, as users are likely to use one or the other, but never both, in the "real world". [1]: https://patchwork.kernel.org/project/linux-mm/patch/20201129004548.1619714-14-namit@vmware.com/ Signed-off-by: Axel Rasmussen Acked-by: Peter Xu --- tools/testing/selftests/vm/userfaultfd.c | 69 ++++++++++++++++++++---- 1 file changed, 60 insertions(+), 9 deletions(-) diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index 0bdfc1955229..0a126c620bc0 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -77,6 +77,11 @@ static int bounces; #define TEST_SHMEM 3 static int test_type; +#define UFFD_FLAGS (O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY) + +/* test using /dev/userfaultfd, instead of userfaultfd(2) */ +static bool test_dev_userfaultfd; + /* exercise the test_uffdio_*_eexist every ALARM_INTERVAL_SECS */ #define ALARM_INTERVAL_SECS 10 static volatile bool test_uffdio_copy_eexist = true; @@ -125,6 +130,8 @@ struct uffd_stats { const char *examples = "# Run anonymous memory test on 100MiB region with 99999 bounces:\n" "./userfaultfd anon 100 99999\n\n" + "# Run the same anonymous memory test, but using /dev/userfaultfd:\n" + "./userfaultfd anon:dev 100 99999\n\n" "# Run share memory test on 1GiB region with 99 bounces:\n" "./userfaultfd shmem 1000 99\n\n" "# Run hugetlb memory test on 256MiB region with 50 bounces:\n" @@ -141,6 +148,14 @@ static void usage(void) "[hugetlbfs_file]\n\n"); fprintf(stderr, "Supported : anon, hugetlb, " "hugetlb_shared, shmem\n\n"); + fprintf(stderr, "'Test mods' can be joined to the test type string with a ':'. " + "Supported mods:\n"); + fprintf(stderr, "\tsyscall - Use userfaultfd(2) (default)\n"); + fprintf(stderr, "\tdev - Use /dev/userfaultfd instead of userfaultfd(2)\n"); + fprintf(stderr, "\nExample test mod usage:\n"); + fprintf(stderr, "# Run anonymous memory test with /dev/userfaultfd:\n"); + fprintf(stderr, "./userfaultfd anon:dev 100 99999\n\n"); + fprintf(stderr, "Examples:\n\n"); fprintf(stderr, "%s", examples); exit(1); @@ -154,12 +169,14 @@ static void usage(void) ret, __LINE__); \ } while (0) -#define err(fmt, ...) \ +#define errexit(exitcode, fmt, ...) \ do { \ _err(fmt, ##__VA_ARGS__); \ - exit(1); \ + exit(exitcode); \ } while (0) +#define err(fmt, ...) errexit(1, fmt, ##__VA_ARGS__) + static void uffd_stats_reset(struct uffd_stats *uffd_stats, unsigned long n_cpus) { @@ -383,13 +400,29 @@ static void assert_expected_ioctls_present(uint64_t mode, uint64_t ioctls) } } +static int __userfaultfd_open_dev(void) +{ + int fd, _uffd = -1; + + fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC); + if (fd < 0) + return -1; + + _uffd = ioctl(fd, USERFAULTFD_IOC_NEW, UFFD_FLAGS); + close(fd); + return _uffd; +} + static void userfaultfd_open(uint64_t *features) { struct uffdio_api uffdio_api; - uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY); + if (test_dev_userfaultfd) + uffd = __userfaultfd_open_dev(); + else + uffd = syscall(__NR_userfaultfd, UFFD_FLAGS); if (uffd < 0) - err("userfaultfd syscall not available in this kernel"); + errexit(KSFT_SKIP, "creating userfaultfd failed"); uffd_flags = fcntl(uffd, F_GETFD, NULL); uffdio_api.api = UFFD_API; @@ -1584,8 +1617,6 @@ unsigned long default_huge_page_size(void) static void set_test_type(const char *type) { - uint64_t features = UFFD_API_FEATURES; - if (!strcmp(type, "anon")) { test_type = TEST_ANON; uffd_test_ops = &anon_uffd_test_ops; @@ -1603,9 +1634,29 @@ static void set_test_type(const char *type) test_type = TEST_SHMEM; uffd_test_ops = &shmem_uffd_test_ops; test_uffdio_minor = true; - } else { - err("Unknown test type: %s", type); } +} + +static void parse_test_type_arg(const char *raw_type) +{ + char *buf = strdup(raw_type); + uint64_t features = UFFD_API_FEATURES; + + while (buf) { + const char *token = strsep(&buf, ":"); + + if (!test_type) + set_test_type(token); + else if (!strcmp(token, "dev")) + test_dev_userfaultfd = true; + else if (!strcmp(token, "syscall")) + test_dev_userfaultfd = false; + else + err("unrecognized test mod '%s'", token); + } + + if (!test_type) + err("failed to parse test type argument: '%s'", raw_type); if (test_type == TEST_HUGETLB) page_size = default_huge_page_size(); @@ -1653,7 +1704,7 @@ int main(int argc, char **argv) err("failed to arm SIGALRM"); alarm(ALARM_INTERVAL_SECS); - set_test_type(argv[1]); + parse_test_type_arg(argv[1]); nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); nr_pages_per_cpu = atol(argv[2]) * 1024*1024 / page_size /