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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A923DEB64DC for ; Mon, 17 Jul 2023 17:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231262AbjGQRlC (ORCPT ); Mon, 17 Jul 2023 13:41:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229701AbjGQRlC (ORCPT ); Mon, 17 Jul 2023 13:41:02 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4D1511C for ; Mon, 17 Jul 2023 10:40:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1689615613; h=from:from: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; bh=F4zjgn0cYB98ujXpFEQtfUyI4X2KQIDCSEQefL4BBIc=; b=R7F/xu9Mc8h0fWEtL3oiEqmD1P3ORkVylDqRcBhg1GAVQizQVVQgbf2jQPn/6EL2Y4l+Z8 89/7jf4XXrRGtgfukhbw+C6/NOwF+sP5p/euXsmpI0h7sOAZsKfhBXV+yalvGIgUiVxTOF p5fkBFz7z6F931H62q9C4LIvub9BbAI= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-549-f0zjSi9zMfajXB3HMCz9RA-1; Mon, 17 Jul 2023 13:40:12 -0400 X-MC-Unique: f0zjSi9zMfajXB3HMCz9RA-1 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-315a03cae87so2259217f8f.0 for ; Mon, 17 Jul 2023 10:40:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689615611; x=1692207611; h=content-transfer-encoding:in-reply-to:subject:organization:from :references:cc:to:content-language:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=F4zjgn0cYB98ujXpFEQtfUyI4X2KQIDCSEQefL4BBIc=; b=iMYDFLBRlTMH9cMLJ+0nVZCLAWX9/I0SWvkvBjhZALrsIN3iFon6OQ7SZQNMdGO65L D2g3w/XYXa+u4uw0SXo2fAq0xxmN+bTNbtNqAvj3tK6ApKnL0zIKRwJ3GSLBs5nfI9dA +MWtgB83B0ZZEBX60pJuMppbFnRGklfBYQsvowdiWKq94rejJy3TygMaWP5k5TL1eQ2x POD99mXGX3pV+TTgZtF6GNqOQ4pErb/MRDtx4jp59sQgzjcCxcvwC6feoXq7ru4e1VdR MrXhBwSjYCpBQJYpKT2nrHMgkvJK4GT6MM+zL1fAPLL8QJGhiYfeK0W+OgdAdOU67yG6 FMOg== X-Gm-Message-State: ABy/qLYC5LiIwwyhR2chTyx0uUYf1w7aW2lEXpb8Qnf/910sVnFg1IwD n8TNB08/JbruPwsj4cYe5Dqaey3nv+AqBiM7t8aeMAIJu8g5EyaQHG/FdV26/4Dr8RptMrp2Imx yxhVnyMbUV8w3S8r+ZDwEm07n02db X-Received: by 2002:a5d:6a4b:0:b0:314:2d59:c6d5 with SMTP id t11-20020a5d6a4b000000b003142d59c6d5mr8812528wrw.15.1689615611229; Mon, 17 Jul 2023 10:40:11 -0700 (PDT) X-Google-Smtp-Source: APBJJlHEPgjdDbvTWro3bKwzreEOmxLeSINhxQaDSvP7WJA9cGucuWmHNwMsfnwVewA5GsbLTJHKRQ== X-Received: by 2002:a5d:6a4b:0:b0:314:2d59:c6d5 with SMTP id t11-20020a5d6a4b000000b003142d59c6d5mr8812516wrw.15.1689615610882; Mon, 17 Jul 2023 10:40:10 -0700 (PDT) Received: from [192.168.3.108] (p5b0c62d6.dip0.t-ipconnect.de. [91.12.98.214]) by smtp.gmail.com with ESMTPSA id m3-20020a5d56c3000000b0030ae3a6be4asm42184wrw.72.2023.07.17.10.40.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 Jul 2023 10:40:10 -0700 (PDT) Message-ID: <20501a7c-19f6-4154-aebc-49df04c9b043@redhat.com> Date: Mon, 17 Jul 2023 19:40:09 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Content-Language: en-US To: Ryan Roberts , Andrew Morton , Shuah Khan , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Mark Brown , John Hubbard , Florent Revest , Peter Xu Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org References: <20230717103152.202078-1-ryan.roberts@arm.com> <20230717103152.202078-7-ryan.roberts@arm.com> From: David Hildenbrand Organization: Red Hat Subject: Re: [PATCH v2 6/8] selftests/mm: Make migration test robust to failure In-Reply-To: <20230717103152.202078-7-ryan.roberts@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On 17.07.23 12:31, Ryan Roberts wrote: > The `migration` test currently has a number of robustness problems that > cause it to hang and leak resources. > > Timeout: There are 3 tests, which each previously ran for 60 seconds. > However, the timeout in mm/settings for a single test binary was set to > 45 seconds. So when run using run_kselftest.sh, the top level timeout > would trigger before the test binary was finished. Solve this by meeting > in the middle; each of the 3 tests now runs for 20 seconds (for a total > of 60), and the top level timeout is set to 90 seconds. > > Leaking child processes: the `shared_anon` test fork()s some children > but then an ASSERT() fires before the test kills those children. The > assert causes immediate exit of the parent and leaking of the children. > Furthermore, if run using the run_kselftest.sh wrapper, the wrapper > would get stuck waiting for those children to exit, which never happens. > Solve this by deferring any asserts until after the children are killed. > The same pattern is used for the threaded tests for uniformity. > > With these changes, the test binary now runs to completion on arm64, > with 2 tests passing and the `shared_anon` test failing. > > Signed-off-by: Ryan Roberts > --- > tools/testing/selftests/mm/migration.c | 14 ++++++++++---- > tools/testing/selftests/mm/settings | 2 +- > 2 files changed, 11 insertions(+), 5 deletions(-) > > diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c > index 379581567f27..189d7d9070e8 100644 > --- a/tools/testing/selftests/mm/migration.c > +++ b/tools/testing/selftests/mm/migration.c > @@ -15,7 +15,7 @@ > #include > > #define TWOMEG (2<<20) > -#define RUNTIME (60) > +#define RUNTIME (20) > > #define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1))) > > @@ -118,6 +118,7 @@ TEST_F_TIMEOUT(migration, private_anon, 2*RUNTIME) > { > uint64_t *ptr; > int i; > + int ret; > > if (self->nthreads < 2 || self->n1 < 0 || self->n2 < 0) > SKIP(return, "Not enough threads or NUMA nodes available"); > @@ -131,9 +132,10 @@ TEST_F_TIMEOUT(migration, private_anon, 2*RUNTIME) > if (pthread_create(&self->threads[i], NULL, access_mem, ptr)) > perror("Couldn't create thread"); > > - ASSERT_EQ(migrate(ptr, self->n1, self->n2), 0); > + ret = migrate(ptr, self->n1, self->n2); > for (i = 0; i < self->nthreads - 1; i++) > ASSERT_EQ(pthread_cancel(self->threads[i]), 0); > + ASSERT_EQ(ret, 0); Why is that required? This does not involve fork. > } > > /* > @@ -144,6 +146,7 @@ TEST_F_TIMEOUT(migration, shared_anon, 2*RUNTIME) > pid_t pid; > uint64_t *ptr; > int i; > + int ret; > > if (self->nthreads < 2 || self->n1 < 0 || self->n2 < 0) > SKIP(return, "Not enough threads or NUMA nodes available"); > @@ -161,9 +164,10 @@ TEST_F_TIMEOUT(migration, shared_anon, 2*RUNTIME) > self->pids[i] = pid; > } > > - ASSERT_EQ(migrate(ptr, self->n1, self->n2), 0); > + ret = migrate(ptr, self->n1, self->n2); > for (i = 0; i < self->nthreads - 1; i++) > ASSERT_EQ(kill(self->pids[i], SIGTERM), 0); > + ASSERT_EQ(ret, 0); Might be cleaner to also: diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c index 379581567f27..b3f12b9847ec 100644 --- a/tools/testing/selftests/mm/migration.c +++ b/tools/testing/selftests/mm/migration.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -155,10 +156,12 @@ TEST_F_TIMEOUT(migration, shared_anon, 2*RUNTIME) memset(ptr, 0xde, TWOMEG); for (i = 0; i < self->nthreads - 1; i++) { pid = fork(); - if (!pid) + if (!pid) { + prctl(PR_SET_PDEATHSIG, SIGHUP); access_mem(ptr); - else + } else { self->pids[i] = pid; + } } ASSERT_EQ(migrate(ptr, self->n1, self->n2), 0); Then, whenever the parent dies, all child processes get zapped. -- Cheers, David / dhildenb