Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752145Ab0DBSSQ (ORCPT ); Fri, 2 Apr 2010 14:18:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2613 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750842Ab0DBSSH (ORCPT ); Fri, 2 Apr 2010 14:18:07 -0400 Date: Fri, 2 Apr 2010 14:17:54 -0400 From: Vivek Goyal To: Divyesh Shah Cc: jens.axboe@oracle.com, linux-kernel@vger.kernel.org, nauman@google.com, ctalbott@google.com Subject: Re: [PATCH 2/3] blkio: Add io controller stats like Message-ID: <20100402181754.GC3516@redhat.com> References: <20100401215541.2843.79107.stgit@austin.mtv.corp.google.com> <20100401220109.2843.36040.stgit@austin.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100401220109.2843.36040.stgit@austin.mtv.corp.google.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 31 On Thu, Apr 01, 2010 at 03:01:24PM -0700, Divyesh Shah wrote: [..] > +#define GET_STAT(__VAR, __CONV) \ > +uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int dummy) \ > +{ \ > + uint64_t data = blkg->stats.__VAR; \ > + if (__CONV) \ > + data = (uint64_t)jiffies_to_msecs(data) * NSEC_PER_MSEC;\ > + return data; \ > +} > + Hi Divyesh, I think now you are exporting blkio.time in ns instead of ms? - First of all your are breaking ABI. - Secondly, how does that help. You are capturing all your slice used stats in ms. You already lost any ns granularity. What's the point in converting these to ns now? - Does user space software really need that fine grained accounting. If this information is used for charging purposes, isn't ms good enough. Thanks Vivek -- 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/