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 242EAC27C54 for ; Thu, 6 Jun 2024 15:56:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B1E176B009C; Thu, 6 Jun 2024 11:56:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ACFAD6B00A9; Thu, 6 Jun 2024 11:56:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 948286B00B1; Thu, 6 Jun 2024 11:56:53 -0400 (EDT) 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 750E56B009C for ; Thu, 6 Jun 2024 11:56:53 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 2522D1204D5 for ; Thu, 6 Jun 2024 15:56:53 +0000 (UTC) X-FDA: 82200917106.09.4C3C5FC Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf06.hostedemail.com (Postfix) with ESMTP id C1A41180004 for ; Thu, 6 Jun 2024 15:56:50 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=AN4pGfMk; spf=pass (imf06.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1717689410; 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=rICVcq7FiKIUG7u7jIEiVO2tUcrUM6iWDXfWLjwwGZ4=; b=JEsuiqnqrMholBCLqM1i1mOcvXDVuFyi0ojnNegcRpn4rVJ/fZhGMADkXvMqIwHvaJItUX vVRcZCIvW1LLT0Tb0EG8JSAfpL8DTOKn/c5Nl+rJ5bHXN9UfsLtufOb5cMqqQMwpw4tA/U VSQeeiWA4ToTmglZ2IS4VxQBLZdDRpY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1717689410; a=rsa-sha256; cv=none; b=XyT4Yqmbh1PhNRJnw56B5iybsWu1oTdS1gmv2zM88c1/MByBW8VIGwoC3N9W+tOJjn2wYX 8qD5omdkEkLenRqBGMtTzlXGX/KgC+lXuuWtGZaXHCVedQaOfURDaQedxld5WJudA8o0M3 w8AGnHe4pFYObJOrqqBhPeDQ2rbrFso= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=AN4pGfMk; spf=pass (imf06.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1717689410; 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:autocrypt:autocrypt; bh=rICVcq7FiKIUG7u7jIEiVO2tUcrUM6iWDXfWLjwwGZ4=; b=AN4pGfMkLZ6wamEhK/Iokg/g7L1L0JW97dYbjHPLygOueqEmooKopW3hlwINICnTBpNkED PiL45DGsseFzXTF6MeKDQIu/38Q9Nkoh9EtrFI/ZJtZLkCpaJYfX8F2sta5UYJxcCwoSZS J2knxeWkX8303DRd2hkbx2f3BROv+Jo= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-496-XEfOUxRhPxSy3c-JssRaIw-1; Thu, 06 Jun 2024 11:56:46 -0400 X-MC-Unique: XEfOUxRhPxSy3c-JssRaIw-1 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-4215a04220eso11233585e9.3 for ; Thu, 06 Jun 2024 08:56:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717689405; x=1718294205; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=rICVcq7FiKIUG7u7jIEiVO2tUcrUM6iWDXfWLjwwGZ4=; b=nrMUuN3p7b/t2EeoJ8wHCgWlt+QgfBmy+36MKGk/tqmLJLxAnpEhfawXcynMRX5Fd4 4MfFfxldEWV9DJC2mA5LkuBELU6kbgu05uY2dCYgHjAZP5RfG7IJU/kXRpm1hiUav23p H9gH8DJcQOxVbDdyLnaOhik6ce8y/rKWdWwHpE836lopyc/1tzSgvITFL6x6TQV60+Kb 7+eMMXSYdDlTg87flAmzsfcfnN2zHTcttS0D/vyC3Dyhtwh5uLFsBes5OAuUsixIHUXh wzFJ2Q2eXTwHw+fMjpbF4G+eK/JmqvfWMuwu47kK9tG6BOxTcCSIX+6DfstQKCIp7dXO oLWQ== X-Forwarded-Encrypted: i=1; AJvYcCV0NHDQNjAlQmvfyGuaA6XBWpNUBQvH2Z7jnEQ1so85q5BUXtgyKX/XQNDjRvgySCKQno+rwNX95EDTRMmjey0VUas= X-Gm-Message-State: AOJu0YxuKxqEFesJ7ZsREk49xRH6hBl2VTxG4gdLgJCr+Ujaa8G2ATNU qfopb5hJOgDy9xQAWQ1/xwpRfVzofD2uGe1oAs00anbvPLm7jGwOSfjNDSJpEgnwOfy2l7aEkbq e6LoQLPYwmOUAzi2ym9JsUwItQT9FsVcjDd1/n+QiwLTPzzMu X-Received: by 2002:a05:600c:19c7:b0:419:f911:680a with SMTP id 5b1f17b1804b1-421649ec4f1mr1464635e9.1.1717689405107; Thu, 06 Jun 2024 08:56:45 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFICeY1PkRTCZuslnCo8zVl10rT73fNAObHJppOV3wt8/nIAR3iHGtkV3plGrDo/QKT1YfJ2Q== X-Received: by 2002:a05:600c:19c7:b0:419:f911:680a with SMTP id 5b1f17b1804b1-421649ec4f1mr1464195e9.1.1717689404416; Thu, 06 Jun 2024 08:56:44 -0700 (PDT) Received: from ?IPV6:2003:cb:c710:8800:a73c:ec5b:c02c:5e0b? (p200300cbc7108800a73cec5bc02c5e0b.dip0.t-ipconnect.de. [2003:cb:c710:8800:a73c:ec5b:c02c:5e0b]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-421580fe371sm60070155e9.1.2024.06.06.08.56.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 Jun 2024 08:56:44 -0700 (PDT) Message-ID: <5b4e7ef2-3ced-4d4a-989c-e99b06598d32@redhat.com> Date: Thu, 6 Jun 2024 17:56:43 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/mm: use volatile keyword to not optimize mmap read variable To: "Pankaj Raghav (Samsung)" , Shuah Khan , Andrew Morton Cc: willy@infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, gost.dev@samsung.com, mcgrof@kernel.org, linux-kselftest@vger.kernel.org, Zi Yan , Pankaj Raghav References: <20240606135835.600022-1-kernel@pankajraghav.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20240606135835.600022-1-kernel@pankajraghav.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: C1A41180004 X-Rspam-User: X-Stat-Signature: 76cwmwfas7u84oie9j5rig7wmdhkum9f X-HE-Tag: 1717689410-442188 X-HE-Meta: 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 GxACuBP0 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 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 06.06.24 15:58, Pankaj Raghav (Samsung) wrote: > From: Pankaj Raghav > > create_pagecache_thp_and_fd() in split_huge_page_test.c used the > variable dummy to perform mmap read. > > However, this test was skipped even on XFS which has large folio > support. The issue was compiler (gcc 13.2.0) was optimizing out the > dummy variable, therefore, not creating huge page in the page cache. > > Add volatile keyword to force compiler not to optimize out the loop > where we read from the mmaped addr. > > Signed-off-by: Pankaj Raghav > --- > tools/testing/selftests/mm/split_huge_page_test.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c > index d3c7f5fb3e7b..c573a58f80ab 100644 > --- a/tools/testing/selftests/mm/split_huge_page_test.c > +++ b/tools/testing/selftests/mm/split_huge_page_test.c > @@ -300,7 +300,7 @@ int create_pagecache_thp_and_fd(const char *testfile, size_t fd_size, int *fd, > char **addr) > { > size_t i; > - int __attribute__((unused)) dummy = 0; > + volatile int __attribute__((unused)) dummy = 0; > > srand(time(NULL)); > > > base-commit: d97496ca23a2d4ee80b7302849404859d9058bcd The rick we do in some other tests is: char *tmp; tmp = *whatever; asm volatile("" : "+r" (tmp)); -- Cheers, David / dhildenb