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 X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 039EFC2BB1D for ; Fri, 13 Mar 2020 12:22:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF37120724 for ; Fri, 13 Mar 2020 12:22:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="aB7dTDeW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726715AbgCMMWM (ORCPT ); Fri, 13 Mar 2020 08:22:12 -0400 Received: from mail-qk1-f195.google.com ([209.85.222.195]:44274 "EHLO mail-qk1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726216AbgCMMWM (ORCPT ); Fri, 13 Mar 2020 08:22:12 -0400 Received: by mail-qk1-f195.google.com with SMTP id f198so12014112qke.11 for ; Fri, 13 Mar 2020 05:22:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=M68LOzWrZXFkDlXwdy0ZNT0fx/04UzLIGSmzsrY5jic=; b=aB7dTDeWRO4el1VBMvTJwNIIBoz2Wjnhxho0HYufVMJEfjmBfOpuXLwrcL7DLYTSVL iXSb0m0D+aT/tYpWBsL2bNpvPSJWkIZjs2CfdAUan/l98zTxRdtTma6YYvzo8IsdjmeC XjpTXwss/3scxmXZ1vucQUgiPyTk1Jlr3ieck4Dq0IQzCKdB9GNugPvvl2PU66GQC0ba r3+0UJMv2E+3dxC1Pp2bQ1aBHqUttR8DiIv7dEy+02WZk7GEVLrH8xgIr8IkFraOVMwa fvZKJh6aF9YuCjcvg3hbWNErJpk7l5MvrGncuH2L2y+/HWZyoRfI4t6qe0Y3hOR0A85C 4iLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=M68LOzWrZXFkDlXwdy0ZNT0fx/04UzLIGSmzsrY5jic=; b=E42cl9QuE4I3QdzZqklXNO2oBrsm0lOoJc2/xJyGg1wq3rtsqZCdEr85wCoxYjcDm1 +sL9Zkn1H/Ll9ZOVyP8oOQ7SNp49AYwh/uMEuKfjSXDR4JuBSeqpphuzFIlV3dUhSbJ5 fESZMQgZsThULcvbTu9J7fRhZ6TmG9DxoA/h9Li9PpDXvw7FsAms9bNUTOpXxZAUR3mQ qC+Vy0+NzC1GO6hBzb/Wu8PUOmuSRLKOiVjZ81zK9L0rwzAD1zvdNXITPYh3s1z1yETu xOTBcWAPXMHIEUfB5ys0nqrVG3kkC3l1JnFn6lwl1KcD6q7LRg0zArNQn77ZaV5Nf0T4 SvzQ== X-Gm-Message-State: ANhLgQ1HJhrkbUBNrXnjJD+seQjhNKeU5R4yRFdyM59mK4MSpefFvNPv WUv5HUgt2SY/itG7KpThI1pY8w== X-Google-Smtp-Source: ADFU+vu2uTBKtOSnaTFVMBpQbNxa0sfETj3EWskkZER6lw6bscuPlfohRdlH9YY8sBRl2pVyOlrNHA== X-Received: by 2002:a37:648:: with SMTP id 69mr13005055qkg.353.1584102131258; Fri, 13 Mar 2020 05:22:11 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-142-68-57-212.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.68.57.212]) by smtp.gmail.com with ESMTPSA id t55sm30553520qte.24.2020.03.13.05.22.10 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 13 Mar 2020 05:22:10 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1jCjKM-0001tj-5O; Fri, 13 Mar 2020 09:22:10 -0300 Date: Fri, 13 Mar 2020 09:22:10 -0300 From: Jason Gunthorpe To: Souptick Joarder Cc: jglisse@redhat.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/hmm.c : Remove additional check for lockdep_assert_held() Message-ID: <20200313122210.GB31668@ziepe.ca> References: <1584065460-22205-1-git-send-email-jrdr.linux@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1584065460-22205-1-git-send-email-jrdr.linux@gmail.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 13, 2020 at 07:41:00AM +0530, Souptick Joarder wrote: > walk_page_range() already has a check for lockdep_assert_held(). > So additional check for lockdep_assert_held() can be removed from > hmm_range_fault(). Is there a reason why you think this redundancy is bad? IMHO it makes it easier to understand the API contract if key top level APIs have their assumptions coded in lockdep. Jason