From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 0F8947D00B for ; Tue, 28 Aug 2018 22:54:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727501AbeH2Csh (ORCPT ); Tue, 28 Aug 2018 22:48:37 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:52236 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727366AbeH2Csh (ORCPT ); Tue, 28 Aug 2018 22:48:37 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3446F40201C3; Tue, 28 Aug 2018 22:54:46 +0000 (UTC) Received: from llong.remote.csb (ovpn-123-12.rdu2.redhat.com [10.10.123.12]) by smtp.corp.redhat.com (Postfix) with ESMTP id DC50F2166B41; Tue, 28 Aug 2018 22:54:44 +0000 (UTC) Subject: Re: [PATCH 0/2] fs/dcache: Track # of negative dentries To: Andrew Morton Cc: Alexander Viro , Jonathan Corbet , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, "Luis R. Rodriguez" , Kees Cook , Linus Torvalds , Jan Kara , "Paul E. McKenney" , Ingo Molnar , Miklos Szeredi , Matthew Wilcox , Larry Woodman , James Bottomley , "Wangkai (Kevin C)" , Michal Hocko References: <1535476780-5773-1-git-send-email-longman@redhat.com> <20180828155006.a6a94a7ba64ac4ce6b8b190c@linux-foundation.org> From: Waiman Long Organization: Red Hat Message-ID: <4284b67f-51bd-88d9-b7c4-8303179127b7@redhat.com> Date: Tue, 28 Aug 2018 18:54:44 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20180828155006.a6a94a7ba64ac4ce6b8b190c@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Tue, 28 Aug 2018 22:54:46 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Tue, 28 Aug 2018 22:54:46 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'longman@redhat.com' RCPT:'' Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 08/28/2018 06:50 PM, Andrew Morton wrote: > On Tue, 28 Aug 2018 13:19:38 -0400 Waiman Long wrote: > >> This patchset is a reduced scope version of the >> patchset "fs/dcache: Track & limit # of negative dentries" >> (https://lkml.org/lkml/2018/7/12/586). Only the first 2 patches are >> included to track the number of negative dentries in the system as well >> as making negative dentries more easily reclaimed than positive ones. >> >> There are controversies on limiting number of negative dentries as it may >> make negative dentries special in term of how memory resources are to >> be managed in the kernel. However, I don't believe I heard any concern >> about tracking the number of negative dentries in the system. So it is >> better to separate that out and get it done with. We can deal with the >> controversial part later on. > Seems reasonable. > > It would be nice to see testing results please. Quite comprehensive > ones. > > And again, an apparently permanent feature of this patchset is that the > changelogs fail to provide descriptions of real-world problems with the > existing code. Please do provide those (comprehensive) descriptions and > demonstrate that these changes resolve those problems. > > Also, a grumpynit: with 100% uniformity, the vfs presently refers to > negative dentries with the string "negative" in the identifier. This > patchset abbreviates that to "neg". > Will do. Cheers, Longman