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]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5E17C433FE for ; Thu, 19 May 2022 19:13:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C5F836B0073; Thu, 19 May 2022 15:13:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C0FBC6B0075; Thu, 19 May 2022 15:13:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AB0418D0001; Thu, 19 May 2022 15:13:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 9BEE96B0073 for ; Thu, 19 May 2022 15:13:55 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 6A51421106 for ; Thu, 19 May 2022 19:13:55 +0000 (UTC) X-FDA: 79483442430.14.4EBC9E0 Received: from mail-io1-f50.google.com (mail-io1-f50.google.com [209.85.166.50]) by imf17.hostedemail.com (Postfix) with ESMTP id A5174400DC for ; Thu, 19 May 2022 19:13:29 +0000 (UTC) Received: by mail-io1-f50.google.com with SMTP id e194so6720853iof.11 for ; Thu, 19 May 2022 12:13:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6/y06+DLzN/eyg4fXfBHtcLRTnFYxYLYCPqBTJsbH6s=; b=Hr7YTVx/XDlLAKxrqvGt3HM8lkbQ7yU2d3o62RUBreCJgrHoA8OSdL53fbQ3KLFiO2 /1vHpfewwHUWgXcLIj3wMgTZ5sGELoRatnJpC5h8N64AtjuyzTrKNDDMAgk+T9w7cCeF Wg4EpROQ9lznY84WpbrXLJWghT/JB4bwz2w3PVWYuRB3zMZAcBIpkH5LdEYGfnVJpdOt BfSvIidMaMzxVrCEapVPuz5jtfaWcxAdLMsxpucS1Nk1ppff19DluwXMBAn4FJlGa24U mln4eXx0GXrxxAde1IcxQBsW5gzB/5zTgmkb5K81Vk8Gua1sTGxvoARNWc84yLIwalG9 /3sg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6/y06+DLzN/eyg4fXfBHtcLRTnFYxYLYCPqBTJsbH6s=; b=GIalZpqXnXg+0uZFWsC3cViGRIkadn4D/9wk1jE6OLiChBRCd5NjDRftUyFblpVZtS sZkqi+FjfQIMbnIs8L6p0mTw48EGU2AZMt14/RCu73XEPx1Qt1MsdKbG0ov1KQOJdPi9 WfhcSrEwjKztanayZ6NDaVOtJQFeeUUaAqDX4mYA0JyPVLKcIlfZ+yZZDuX3xoJHiSWz I3Tv8z163UF/qCWDk5C3s86TDKANAV1y2rLKhpTMeRRRBNXZ+Yai4G7sBBnBDt3YTOPy hhae6XNyV3HnBuqtN6YqPsrUTQLHWwmWMycQQT4i2elBHvDqYWsRgq+XIW4rAyhkdrgC CY9w== X-Gm-Message-State: AOAM532Af9HUWBexncOyBVTJK6U9IIstzUAXwLaxaPMHH1VizX7QcMSU OVr/7c672tXouMrqyCRNaz6SYDMilVS871xYtutzKg== X-Google-Smtp-Source: ABdhPJy0GdftMdljZ/DggUvp858hbLHvZ0ZTwbMCuqHX0TPJ3QqmV+8xMprTqaPj1WirWbD9+n0Ce98OwaQRgHhTvhY= X-Received: by 2002:a05:6638:1693:b0:32b:96d6:5fc0 with SMTP id f19-20020a056638169300b0032b96d65fc0mr3499533jat.167.1652987633996; Thu, 19 May 2022 12:13:53 -0700 (PDT) MIME-Version: 1.0 References: <20220422212945.2227722-1-axelrasmussen@google.com> <20220422212945.2227722-6-axelrasmussen@google.com> In-Reply-To: From: Axel Rasmussen Date: Thu, 19 May 2022 12:13:18 -0700 Message-ID: Subject: Re: [PATCH v2 5/6] userfaultfd: selftests: make /dev/userfaultfd testing configurable To: Shuah Khan Cc: Alexander Viro , Andrew Morton , Charan Teja Reddy , 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 , linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, LKML , Linux MM , Linuxkselftest Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: A5174400DC X-Stat-Signature: pfquhrfra93ex5s5prygfct3cxada8wx Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="Hr7YTVx/"; spf=pass (imf17.hostedemail.com: domain of axelrasmussen@google.com designates 209.85.166.50 as permitted sender) smtp.mailfrom=axelrasmussen@google.com; dmarc=pass (policy=reject) header.from=google.com X-HE-Tag: 1652987609-847777 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: On Tue, Apr 26, 2022 at 9:56 AM Shuah Khan wrote: > > On 4/22/22 3:29 PM, Axel Rasmussen wrote: > > 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 > > --- > > tools/testing/selftests/vm/userfaultfd.c | 41 +++++++++++++++++------- > > 1 file changed, 30 insertions(+), 11 deletions(-) > > > > diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c > > index 12ae742a9981..274522704e40 100644 > > --- a/tools/testing/selftests/vm/userfaultfd.c > > +++ b/tools/testing/selftests/vm/userfaultfd.c > > @@ -142,8 +142,17 @@ static void usage(void) > > { > > fprintf(stderr, "\nUsage: ./userfaultfd " > > "[hugetlbfs_file]\n\n"); > > + > > Remove the extra blank line here. > > > fprintf(stderr, "Supported : anon, hugetlb, " > > "hugetlb_shared, shmem\n\n"); > > + > > Remove the extra blank line here. > > > + fprintf(stderr, "'Test mods' can be joined to the test type string with a ':'. " > > + "Supported mods:\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); > > Update examples above with new test cases if any. Will fix the above comments in v3. > > > exit(1); > > @@ -1610,8 +1619,6 @@ 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; > > @@ -1631,10 +1638,28 @@ 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); > > + } > > At this point, it might make it so much easier and maintainable if > we were to use getopt instead of parsing options. Agreed, I'd like that as well. But, since it's a bigger refactor that affects all test types, I think it may be cleaner to leave it for a follow-up series. > > > +} > > + > > +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 > > + 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(); > > else > > @@ -1681,7 +1706,7 @@ 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 / > > @@ -1719,12 +1744,6 @@ int main(int argc, char **argv) > > } > > printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n", > > nr_pages, nr_pages_per_cpu); > > - > > - test_dev_userfaultfd = false; > > - if (userfaultfd_stress()) > > - return 1; > > - > > - test_dev_userfaultfd = true; > > return userfaultfd_stress(); > > } > > > > > > Same comments as before on fail vs. skip conditions to watch out > for and report them correctly. I think in v3 things will be correct. Basically, in the skip cases we just exit(KSFT_SKIP) directly, instead of relying on the return value here. I'll take a pass and double check though before sending v3. > > thanks, > -- Shuah >