From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932829AbWFZTE1 (ORCPT ); Mon, 26 Jun 2006 15:04:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932831AbWFZTE1 (ORCPT ); Mon, 26 Jun 2006 15:04:27 -0400 Received: from omx2-ext.sgi.com ([192.48.171.19]:53973 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S932829AbWFZTEZ (ORCPT ); Mon, 26 Jun 2006 15:04:25 -0400 Message-ID: <44A02FB0.6000505@sgi.com> Date: Mon, 26 Jun 2006 12:04:16 -0700 From: Jay Lan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040906 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Shailabh Nagar Cc: Andrew Morton , Balbir Singh , Chris Sturtivant , linux-kernel Subject: Re: [RFC][PATCH] delay accounting taskstats interface send tgid once References: <44A02331.8020903@watson.ibm.com> In-Reply-To: <44A02331.8020903@watson.ibm.com> X-Enigmail-Version: 0.86.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Shailabh, Is this patch supposed to go on top of all other patches? Or is it supposed to replace any? I had failure applying this patch on top of all previously applied. - jay Shailabh Nagar wrote: > Send per-tgid data only once during exit of a thread group instead of once with > each member thread exit. > > Currently, when a thread exits, besides its per-tid data, the per-tgid data of > its thread group is also sent out, if its thread group is non-empty. The > per-tgid data sent consists of the sum of per-tid stats for all *remaining* > threads of the thread group. > > This patch modifies this sending in two ways: > > - the per-tgid data is sent only when the last thread of a thread group exits. > This cuts down heavily on the overhead of sending/receiving per-tgid data, > especially when other exploiters of the taskstats interface aren't interested > in per-tgid stats > > - the semantics of the per-tgid data sent are changed. Instead of being the > sum of per-tid data for remaining threads, the value now sent is the true total > accumalated statistics for all threads that are/were part of the thread group. > > The patch also addresses a minor issue where failure of one accounting > subsystem to fill in the taskstats structure was causing the send of taskstats > to not be sent at all. > > The patch has been tested for stability and run cerberus for over 4 hours on > an SMP. > > Signed-off-by: Shailabh Nagar > Signed-off-by: Balbir Singh