Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759200Ab0DBGpV (ORCPT ); Fri, 2 Apr 2010 02:45:21 -0400 Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:43483 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758761Ab0DBGpP (ORCPT ); Fri, 2 Apr 2010 02:45:15 -0400 Date: Fri, 2 Apr 2010 08:45:14 +0200 From: Jens Axboe To: Divyesh Shah Cc: vgoyal@redhat.com, linux-kernel@vger.kernel.org, nauman@google.com, ctalbott@google.com Subject: Re: [PATCH 0/3] blkio: IO controller stats Message-ID: <20100402064514.GW23510@kernel.dk> References: <20100401215541.2843.79107.stgit@austin.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100401215541.2843.79107.stgit@austin.mtv.corp.google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1655 Lines: 34 On Thu, Apr 01 2010, Divyesh Shah wrote: > The following series implements some additional stats for IO controller. > > These stats have helped us debug issues with earlier IO controller > versions and should be useful now as well. > We've been using these stats for monitoring and debugging problems after the > fact as these stats can be collected and stored for later use. > > One might argue that most of this information can be exported using blktrace > when debugging. However, blktrace has non-trivial performance impact and > cannot be always turned on. These stats provide a way for continuous monitoring > without losing much performance on rotational disks. We've been able to look > at these stats and debug issues after problems have been reported in the wild > and understand the IO pattern of the affected workloads. > Some of these stats are also a good data source for high-level analysis and > capacity planning. > > This patchset adds 4 stats and I will send out another patchset later for > stats like io_merged and some stats that can be turned on only for > debugging - idle_time (total time spent idling for this blkio_group), > wait_time (total time spent by the blkio_group waiting before any one of its > queues got a timeslice). I've tried to breakdown the stats and sent the most > basic ones here. Thanks, I think this makes sense. I've applied it for 2.6.35. -- Jens Axboe -- 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/