From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754056AbZGFTvr (ORCPT ); Mon, 6 Jul 2009 15:51:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753094AbZGFTvk (ORCPT ); Mon, 6 Jul 2009 15:51:40 -0400 Received: from smtp.df.ru ([195.42.160.16]:36696 "EHLO smtp.df.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752499AbZGFTvk (ORCPT ); Mon, 6 Jul 2009 15:51:40 -0400 Date: Mon, 6 Jul 2009 23:52:52 +0400 From: Alexey Vlasov To: "H. Peter Anvin" Cc: Ray Lee , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: devpts mounts too slowly Message-ID: <20090706195252.GA7484@beaver.vrungel.ru> References: <20090603142801.GC21646@beaver.vrungel.ru> <4A26EB18.6060907@zytor.com> <20090609161945.811cc01f.akpm@linux-foundation.org> <2c0942db0906091630l1cc79647h8689e9e929ed1bba@mail.gmail.com> <4A2EF833.6080300@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <4A2EF833.6080300@zytor.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 09, 2009 at 05:02:59PM -0700, H. Peter Anvin wrote: > A quick script seems to confirm that the time starts creeping up as the > number of mount points increase; on my Core i7 system the 10000th mount > takes around 50 ms whereas the early instances are submillisecond, and > the increase *seems* to be O(n log n) or thereabouts -- slightly > superlinear but not a good fit for a power law. I have prepared a new machine for testing, and I don't see any slowdown by mounting devpts. Total mounts on it: # wc -l /proc/mounts 153481 /proc/mounts # fgrep -c devpts /proc/mounts 10231 On my other servers there're slowdown already by this number of: # wc -l /proc/mounts 49889 /proc/mounts # fgrep -c devpts /proc/mounts 3323 But the first box is totally empty, others are in use, may be this matters? -- BRGDS. Alexey Vlasov.