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=ham 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 9A80ECA9ECF for ; Fri, 1 Nov 2019 10:59:03 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 597832086D for ; Fri, 1 Nov 2019 10:59:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chrisdown.name header.i=@chrisdown.name header.b="VwZmEH6B" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 597832086D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chrisdown.name Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E33F16B0005; Fri, 1 Nov 2019 06:59:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DE47B6B0006; Fri, 1 Nov 2019 06:59:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CD55B6B0007; Fri, 1 Nov 2019 06:59:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0096.hostedemail.com [216.40.44.96]) by kanga.kvack.org (Postfix) with ESMTP id AD1C26B0005 for ; Fri, 1 Nov 2019 06:59:02 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id E98238249980 for ; Fri, 1 Nov 2019 10:59:01 +0000 (UTC) X-FDA: 76107411282.20.spoon14_89036cbac1f33 X-HE-Tag: spoon14_89036cbac1f33 X-Filterd-Recvd-Size: 3208 Received: from mail-wm1-f65.google.com (mail-wm1-f65.google.com [209.85.128.65]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Fri, 1 Nov 2019 10:59:01 +0000 (UTC) Received: by mail-wm1-f65.google.com with SMTP id 11so8946138wmk.0 for ; Fri, 01 Nov 2019 03:59:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=LtFp0F0HrsUYyNBlzjAg/7imere0s3lC3VUOl+c6wWo=; b=VwZmEH6BFuBX/lEfDq2gTf28+aE6bseQhEvwyXhZetLJ4XDt/sc7VtvJm2m6W3fQmY no1u3HUstUiMEtr5X1fKOoazXhc1ODwZ45XAWZVFgdDjaDzy9pJD1gt4iGfDW/vbiDzh pY0rw1SBF/npTDRTKj0yNA99/wWXgRn1wAMXc= 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=LtFp0F0HrsUYyNBlzjAg/7imere0s3lC3VUOl+c6wWo=; b=oV+PGU7YOEt0W1JTuAra79W8kMNXwFWc7rsPq2tp6wsV6zByDxdSafHVTLlRUWfwAz HSjYkTx+3vuunJMoaFiMisbTm0ihxfM5opkyhS3kd6jlvEaj5dGz6WY1VPFGw7CB8b7T PXirt6nMgauEWCugrj+P1UfSsY0+GcLAgzXEFG9GHIoNB9OaXZXw5sIfj4CS2d6ytQFi ZHGrakkqXC2cH09oEYDji7G5ztqX6gQ2cirh9vyx9dFmeP7QsR4uDWkrlvnFe4aAqnVS Qs4XBhZU0WLy9umyTGMtf91A+UhJsSE3fg3iATu5cysT6vCl362jhfw/tPVkajHg6rYc ukJA== X-Gm-Message-State: APjAAAVWamqHwWfJhu6syUFguO3dR1Nst9/K5A8bQWXHevcIbWflrLku RXR2s9ewJO8TzqpBUjN3RDHoPg== X-Google-Smtp-Source: APXvYqw+3+Gejtx1dbHSz1D4wdx8qwJDsgqG3o9gN8mxHqhJ5uVwTa8a/3Zk4qq+GGthKlyftuHaWw== X-Received: by 2002:a1c:7704:: with SMTP id t4mr8981357wmi.4.1572605940145; Fri, 01 Nov 2019 03:59:00 -0700 (PDT) Received: from localhost ([2620:10d:c092:180::1:f970]) by smtp.gmail.com with ESMTPSA id n13sm1507441wmi.25.2019.11.01.03.58.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Nov 2019 03:58:59 -0700 (PDT) Date: Fri, 1 Nov 2019 10:58:58 +0000 From: Chris Down To: Johannes Weiner Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH] kernel: sysctl: make drop_caches write-only Message-ID: <20191101105858.GA690103@chrisdown.name> References: <20191031221602.9375-1-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20191031221602.9375-1-hannes@cmpxchg.org> User-Agent: Mutt/1.12.2 (2019-09-21) 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: Johannes Weiner writes: >Currently, the drop_caches proc file and sysctl read back the last >value written, suggesting this is somehow a stateful setting instead >of a one-time command. Make it write-only, like e.g. compact_memory. > >Signed-off-by: Johannes Weiner Since we already have the kmsg notifier when it's used, this seems reasonable to me. Acked-by: Chris Down