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 C8BDDC7EE2A for ; Mon, 22 May 2023 20:34:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229802AbjEVUen (ORCPT ); Mon, 22 May 2023 16:34:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234802AbjEVUeg (ORCPT ); Mon, 22 May 2023 16:34:36 -0400 Received: from mail-wm1-x32f.google.com (mail-wm1-x32f.google.com [IPv6:2a00:1450:4864:20::32f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44F00103 for ; Mon, 22 May 2023 13:34:35 -0700 (PDT) Received: by mail-wm1-x32f.google.com with SMTP id 5b1f17b1804b1-3f475366514so44954095e9.2 for ; Mon, 22 May 2023 13:34:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1684787673; x=1687379673; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=d1k/J8wtFm5kDn20aklLt0C/fMQkAC0oAe25hCJGf0Q=; b=lBeW+EHJMxul6+5/7kn6rk9lSsCsk82kmOlwBbUowAS1ltePVbyFf7dcIqTvQJdxGi XaR4E3msp2L79vV5+9HDT4OvFHK6PuAALlOtAL3m0k8tUKqnViT3s53wH8Qe6UE9snxs DTbCKVUH7CrqcT44TBncHGmKJJUsdGM3r9lz+zl7JWr5tR6W1XLIIfBrL6G1o5Bz3+RN lfUXD+oo8Jg/97lKiTl+Y5/8P8kxbXCltRxzHh1fOJ4wROuqnB6CWwFsC4pTqBHMtSa1 UGwWTRQYOLsuxX49WlGpyBeadV4E760vAdK3hZcvb1+AmIhpXP/XJYPxk5hA9MepJa1/ StmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684787673; x=1687379673; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=d1k/J8wtFm5kDn20aklLt0C/fMQkAC0oAe25hCJGf0Q=; b=NEsi0xpJnCRf9w4LyWhTBU6lNzYSzUtXKoJka0hxy1v1psbOcc62sI0o6ugYdH8N7/ sSrt2daRhmsY9Z62By8+5EflQ7JovBHZg+b69zPuqmitTWN4p7D5QXjmiKSn56fW4HIf BWYb+EWfyescoVZZlgWjT22eR5U/6mz8z5zqtGbiWPiXEb1kdVVvU1yXlko4+3yCo3vH s3eSnGC2XDWn/Oqp517pNuGKBeKulvlGrwWf0Ie4bduAjMa0qEueAlmXVqK6GmAmeD97 QBSVY3Kh0Xk8Df7L2LVMoMNGjenZwUT+TqaLJ0A999Oz+RXFhXvL+5ED1mpdPV2bFqBw aTJg== X-Gm-Message-State: AC+VfDyYHCl2R39PwEe94iBUAxsjj8LtmggR6hAsiXoGCSiS5mwLoYT0 RaLa3Nlv3cOst+WZSt610rk/+heNyJo= X-Google-Smtp-Source: ACHHUZ7laiEhM3jTpA8y0JkDQEEWh3yB9M8uLoT70L3vrTPn8GfHIb9iH2cn6xSwpud4LrkRul0sNw== X-Received: by 2002:a1c:cc02:0:b0:3f4:fc5e:fbf2 with SMTP id h2-20020a1ccc02000000b003f4fc5efbf2mr8715097wmb.8.1684787673287; Mon, 22 May 2023 13:34:33 -0700 (PDT) Received: from localhost (host81-154-179-160.range81-154.btcentralplus.com. [81.154.179.160]) by smtp.gmail.com with ESMTPSA id l20-20020a7bc454000000b003f42e008c8dsm12664696wmi.44.2023.05.22.13.34.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 May 2023 13:34:32 -0700 (PDT) Date: Mon, 22 May 2023 21:34:31 +0100 From: Lorenzo Stoakes To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mike Rapoport , "Liam R . Howlett" , Vlastimil Babka Subject: Re: [PATCH] mm/mmap: refactor mlock_future_check() Message-ID: References: <20230522082412.56685-1-lstoakes@gmail.com> <20230522132851.ccc9fafac91d7eb9ba922e94@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230522132851.ccc9fafac91d7eb9ba922e94@linux-foundation.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 22, 2023 at 01:28:51PM -0700, Andrew Morton wrote: > On Mon, 22 May 2023 09:24:12 +0100 Lorenzo Stoakes wrote: > > > In all but one instance, mlock_future_check() is treated as a boolean > > function despite returning an error code. In one instance, this error code > > is ignored and replaced with -ENOMEM. > > > > This is confusing, and the inversion of true -> failure, false -> success > > is not warranted. Convert the function to a bool, lightly refactor and > > return true if the check passes, false if not. > > Yup. > > I don't think the name does a good job of conveying the > function's use. > > > - if (mlock_future_check(mm, vm_flags, len)) > > + if (!mlock_future_check(mm, vm_flags, len)) > > return -EAGAIN; > > if (!may_mlock_future(...)) > > or > > if (!mlock_future_ok(...)) > > ? > > Yeah I struggled with this, because the check only triggers if VM_LOCKED. I was originally toying with can_mlock_future() but of course, it also returns true if !VM_LOCKED... I think your suggestion of mlock_future_ok() works well, could you change it to that? Thanks!