From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750712AbWFGCBk (ORCPT ); Tue, 6 Jun 2006 22:01:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750753AbWFGCBk (ORCPT ); Tue, 6 Jun 2006 22:01:40 -0400 Received: from omx2-ext.sgi.com ([192.48.171.19]:19124 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S1750712AbWFGCBj (ORCPT ); Tue, 6 Jun 2006 22:01:39 -0400 Message-ID: <44863376.5020701@sgi.com> Date: Tue, 06 Jun 2006 19:01:26 -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: Balbir Singh , Shailabh Nagar Cc: Andrew Morton , lkml , csturtiv@sgi.com, jamal Subject: taskstats interface for accounting 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 Hi Balbir and Shailabh, I finally have time to think about implementation details of CSA over taskstats interface. I took another look at the taskstats interface proposal and was a little bit nervous. Do you remember i suggested to use #ifdef to cut down traffic and i was told a generic netlink header would serve the purpose? What i see now at Documentation/accounting/taskstats.txt saying NETLINK_GENERIC family is used for unicast query/reply mode. The NETLINK_GENERIC family provides great flexsibility on what to receive. However, CSA only uses the multicast mode to receive from kernel whenever tasks are existing. I guess i would need to read the netlink documentation more carefully to see whether my understanding is correct. Another thing i overlooked when i did the review was that taskstats interface is designed to provide _BOTH_ per task _AND_ per thread accounting data EVERY TIME a task exists. A thread is an aggregate of (per-pid) tasks. Since this type of aggregation is not used in CSA, half of data traffic would be useless. Can we add a way to configure to not send per-thread data to the socket? Regards, jay