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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 C05C7C433E0 for ; Fri, 10 Jul 2020 09:05:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 939A42077D for ; Fri, 10 Jul 2020 09:05:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=rasmusvillemoes.dk header.i=@rasmusvillemoes.dk header.b="fAutD3cY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726955AbgGJJFR (ORCPT ); Fri, 10 Jul 2020 05:05:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726496AbgGJJFQ (ORCPT ); Fri, 10 Jul 2020 05:05:16 -0400 Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A153C08C5DC for ; Fri, 10 Jul 2020 02:05:16 -0700 (PDT) Received: by mail-lj1-x243.google.com with SMTP id 9so5589691ljv.5 for ; Fri, 10 Jul 2020 02:05:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rasmusvillemoes.dk; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=VUmFAc962e5K337BfXwFy3uOoKxsKlxWlo6RdFjoWeU=; b=fAutD3cY5ow4YDV5uFTnEihRtuC7Y68t5bQaAcEGwzsqiN3yEk3pVzn5mMwLm0lOmL VSSvAUFBBhFsy6dQskJH1YPZX9Lx3irhJqVRTFkBdnN8OkHOoKmubOCN0Qrt+lsu2KfL 63RF42ZenfvJ1bMQEXzT4IVxvDFOA2BE2kLwo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=VUmFAc962e5K337BfXwFy3uOoKxsKlxWlo6RdFjoWeU=; b=cJdC3t0NYKG3BMFV1Lr5Dy8OPHHeqLVc3yF8msaS5eLR06VEPyVbnkYPb/eO7UqjGF 9HoyrqGDoVOUL8GV9PD8RLbskkcmXEepoNEPa95U13ZDObTe00Jz4hRL05LihKrrDXK6 KHD3ZP1oTQj1d/sKtK7z1fpeZUUtDDqOQmOEvBgG6CKzbd0Dz9ibVXgUhSqwhFhIEz+L YuxiqmZutFJDbD5TR1YkNVO7WdJHcL1nGjqmcl2dVvtIWJc9o9z346Sq1Sh++KHTkCGd 9kPTe34K7l0ov07EKsphsgtpyitW0dJPncZ/8KEr5ZwcEp7g/NTNYQQ1DyRVBBFEuJQD yltg== X-Gm-Message-State: AOAM532F24AIz/Ka8UKH6Y9YA3s1yhKa3cJc+dEoRhSokM4Pa/ha26aA 8CGZg6oc9kL6kLQqre6ZtuRy3Gob45UbzQfV X-Google-Smtp-Source: ABdhPJyfIcP/PQ2s2693hklug7eNZqe5piHixI/UWoYEV5w5FplqjvG+6fc9SV7PjhrnOvGJY/ELSw== X-Received: by 2002:a2e:8e8a:: with SMTP id z10mr30448109ljk.351.1594371914312; Fri, 10 Jul 2020 02:05:14 -0700 (PDT) Received: from [172.16.11.153] ([81.216.59.226]) by smtp.gmail.com with ESMTPSA id q1sm1687890lji.71.2020.07.10.02.05.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 10 Jul 2020 02:05:13 -0700 (PDT) Subject: Re: [PATCH] kcmp: add separate Kconfig symbol for kcmp syscall To: Cyrill Gorcunov Cc: Andrew Morton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200710075632.14661-1-linux@rasmusvillemoes.dk> <20200710083025.GD1999@grain> From: Rasmus Villemoes Message-ID: <14b4a1f0-3caf-75e4-600a-3de877a92950@rasmusvillemoes.dk> Date: Fri, 10 Jul 2020 11:05:11 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200710083025.GD1999@grain> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/07/2020 10.30, Cyrill Gorcunov wrote: > On Fri, Jul 10, 2020 at 09:56:31AM +0200, Rasmus Villemoes wrote: >> The ability to check open file descriptions for equality (without >> resorting to unreliable fstat() and fcntl(F_GETFL) comparisons) can be >> useful outside of the checkpoint/restore use case - for example, >> systemd uses kcmp() to deduplicate the per-service file descriptor >> store. >> >> Make it possible to have the kcmp() syscall without the full >> CONFIG_CHECKPOINT_RESTORE. >> >> Signed-off-by: Rasmus Villemoes >> --- >> I deliberately drop the ifdef in the eventpoll.h header rather than >> replace with KCMP_SYSCALL; it's harmless to declare a function that >> isn't defined anywhere. > > Could you please point why setting #fidef KCMP_SYSCALL in eventpoll.h > is not suitable? It's just from a general "avoid ifdef clutter if possible" POV. The conditional declaration of the function doesn't really serve any purpose. > Still the overall idea is fine for me, thanks!> > Reviewed-by: Cyrill Gorcunov Thank you. Rasmus