From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754520AbZHaGqx (ORCPT ); Mon, 31 Aug 2009 02:46:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753449AbZHaGqw (ORCPT ); Mon, 31 Aug 2009 02:46:52 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:60082 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752329AbZHaGqv (ORCPT ); Mon, 31 Aug 2009 02:46:51 -0400 Date: Mon, 31 Aug 2009 10:56:29 +0530 From: Balbir Singh To: Guillaume Chazarain Cc: Nikanth Karthikesan , linux-kernel@vger.kernel.org, procps-feedback@lists.sf.net, Albert Cahalan Subject: Re: [PATCH 1/3] taskstats-fork: Add a new taskstats command to get notification on fork/clone Message-ID: <20090831052629.GA16742@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <200907211031.48294.knikanth@suse.de> <20090721060114.GS24157@balbir.in.ibm.com> <200907211154.42563.knikanth@suse.de> <3d8471ca0908301252j15cb33b1j913921bd8fc6704c@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <3d8471ca0908301252j15cb33b1j913921bd8fc6704c@mail.gmail.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 * Guillaume Chazarain [2009-08-30 21:52:22]: > On Tue, Jul 21, 2009 at 8:24 AM, Nikanth Karthikesan wrote: > > Ah.. proc-events was the exact thing, I was looking for! Thanks. > > AFAICT proc-events can only be used by root, so that makes it > unsuitable for *top. > > Anyway, iotop will always have to iterate over all threads to query > their taskstats and other attributes, so the O(nr_threads) complexity > is unavoidable. > Unless you want the stats for tgid in signal struct. In some cases we accumulate, in some we don't. But yes irrespective or kernel/user space the complexity exists. -- Balbir