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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4C4EBC2D0F4 for ; Wed, 1 Apr 2020 08:27:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22DEE20719 for ; Wed, 1 Apr 2020 08:27:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WE3GrsX+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731850AbgDAI1k (ORCPT ); Wed, 1 Apr 2020 04:27:40 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:46294 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726197AbgDAI1k (ORCPT ); Wed, 1 Apr 2020 04:27:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585729658; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=A6T4NzJaYrpl8sbGk+/56cI+lPm3tJ8OvumXbnFWNJs=; b=WE3GrsX+tVaULntMaSkIy2VRSqX8a/4hfCWWemEUdjaH3Y+n1sgPy4c72DiCzINxw5nr77 W2+hxNlTVD0/9GKnml0V3R2qYo9mbGRj7tErnpBu1AbwW80hrCu5mkmsR5Cw6mFWfenosA Lta1hQumAfvWZgF79KFKDxqXQDj7xFA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-28-LPl4n2IlPVKc88TP8mowIg-1; Wed, 01 Apr 2020 04:27:37 -0400 X-MC-Unique: LPl4n2IlPVKc88TP8mowIg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AEE58800D53; Wed, 1 Apr 2020 08:27:34 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-114-243.ams2.redhat.com [10.36.114.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4BEC296B72; Wed, 1 Apr 2020 08:27:30 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <158454408854.2864823.5910520544515668590.stgit@warthog.procyon.org.uk> <50caf93782ba1d66bd6acf098fb8dcb0ecc98610.camel@themaw.net> To: Miklos Szeredi Cc: dhowells@redhat.com, Ian Kent , Linus Torvalds , Al Viro , Linux NFS list , Andreas Dilger , Anna Schumaker , "Theodore Ts'o" , Linux API , linux-ext4@vger.kernel.org, Trond Myklebust , Miklos Szeredi , Christian Brauner , Jann Horn , "Darrick J. Wong" , Karel Zak , Jeff Layton , linux-fsdevel@vger.kernel.org, LSM , linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/13] VFS: Filesystem information [ver #19] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2465265.1585729649.1@warthog.procyon.org.uk> Date: Wed, 01 Apr 2020 09:27:29 +0100 Message-ID: <2465266.1585729649@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Miklos Szeredi wrote: > According to dhowell's measurements processing 100k mounts would take > about a few seconds of system time (that's the time spent by the > kernel to retrieve the data, But the inefficiency of mountfs - at least as currently implemented - scales up with the number of individual values you want to retrieve, both in terms of memory usage and time taken. With fsinfo(), I've tried to batch values together where it makes sense - and there's no lingering memory overhead - no extra inodes, dentries and files required. David