Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965162AbVLOHhP (ORCPT ); Thu, 15 Dec 2005 02:37:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965163AbVLOHhO (ORCPT ); Thu, 15 Dec 2005 02:37:14 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:59349 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S965162AbVLOHhM (ORCPT ); Thu, 15 Dec 2005 02:37:12 -0500 Subject: Re: [patch 6/6] statistics infrastructure - exploitation: zfcp From: Arjan van de Ven To: Martin Peschke Cc: linux-scsi@vger.kernel.org, akpm@osdl.org, linux-kernel@vger.kernel.org, Christoph Hellwig In-Reply-To: <43A0E8E7.1060706@de.ibm.com> References: <43A044E6.7060403@de.ibm.com> <20051214165900.GA26580@infradead.org> <43A0E8E7.1060706@de.ibm.com> Content-Type: text/plain Date: Thu, 15 Dec 2005 08:37:08 +0100 Message-Id: <1134632229.16486.3.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-Spam-Score: -2.8 (--) X-Spam-Report: SpamAssassin version 3.0.4 on pentafluge.infradead.org summary: Content analysis details: (-2.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.8 ALL_TRUSTED Did not pass through any untrusted hosts X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2111 Lines: 51 On Thu, 2005-12-15 at 04:54 +0100, Martin Peschke wrote: > Christoph Hellwig wrote: > > >>+ atomic_t read_num; > >>+ atomic_t write_num; > >>+ struct statistic_interface *stat_if; > >>+ struct statistic *stat_sizes_scsi_write; > >>+ struct statistic *stat_sizes_scsi_read; > >>+ struct statistic *stat_sizes_scsi_nodata; > >>+ struct statistic *stat_sizes_scsi_nofit; > >>+ struct statistic *stat_sizes_scsi_nomem; > >>+ struct statistic *stat_sizes_timedout_write; > >>+ struct statistic *stat_sizes_timedout_read; > >>+ struct statistic *stat_sizes_timedout_nodata; > >>+ struct statistic *stat_latencies_scsi_write; > >>+ struct statistic *stat_latencies_scsi_read; > >>+ struct statistic *stat_latencies_scsi_nodata; > >>+ struct statistic *stat_pending_scsi_write; > >>+ struct statistic *stat_pending_scsi_read; > >>+ struct statistic *stat_erp; > >>+ struct statistic *stat_eh_reset; > >> > >> > > > >NACK. pretty much all of this is generic and doesn't belong into an LLDD. > >We already had this statistics things with emulex and they added various > >bits to the core in response. > > > > > > > > > Agreed. It's not necessarily up to LLDDs to keep track of request sizes, > request latencies, I/O queue utilization, and error recovery conditions > by means of statistics. This could or maybe should be done in a more > central spot. > > With regard to latencies, it might make some difference, though, how > many layers are in between that cause additional delays. Then the > question is which latency one wants to measure. even if the LLDD measures these, the stats belong a level up, so that all LLDD's export the same. I think you got half of Christophs point, but not this last bit: even when it's the LLDD that needs to measure the stat, it still shouldn't be LLDD specific, and thus defined one if not two layers up. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/