From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752258Ab2E2HwJ (ORCPT ); Tue, 29 May 2012 03:52:09 -0400 Received: from oproxy5-pub.bluehost.com ([67.222.38.55]:59480 "HELO oproxy5-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751149Ab2E2HwI (ORCPT ); Tue, 29 May 2012 03:52:08 -0400 Message-ID: <4FC4801F.7080100@tao.ma> Date: Tue, 29 May 2012 15:51:59 +0800 From: Tao Ma User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Vivek Goyal CC: linux-kernel@vger.kernel.org, Tejun Heo Subject: Re: [RFC] block/throttle: Add IO throttled information in blkcg. References: <1337674236-2896-1-git-send-email-tm@tao.ma> <20120522111111.GE3045@redhat.com> In-Reply-To: <20120522111111.GE3045@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Identified-User: {1390:box585.bluehost.com:colyli:tao.ma} {sentby:smtp auth 182.92.247.2 authed with tm@tao.ma} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vivek, On 05/22/2012 07:11 PM, Vivek Goyal wrote: > On Tue, May 22, 2012 at 04:10:36PM +0800, Tao Ma wrote: >> From: Tao Ma >> >> Currently, if the IO is throttled by io-throttle, the SA has no idea of >> the situation and can't report it to the real application user about >> that he/she has to do something. So this patch adds a new interface >> named blkio.throttle.io_throttled which indicates how many IOs are >> currently throttled. > > If the only purpose is to know whether IOs are being throttled, why > not just scan for the rules and see if respective device has any > throttling rules or not. > > Even if you introduce this interface, you will end up scanning for > throttled ios against that particular device. And if IO is not happening > at that moment or if IO rate is not exceeding the rate limit, there > might not be any throttled ios and one might get misled. > > So for your purpose a better interface sounds like scanning for throttling > rules instead of this new interface. > >> >> I am not sure whether it is OK to add this information to the generic >> blkcg since it is only io-throttle related, but I don't find a way to >> only store it into the blkcg io-throttle. And that's the reason this >> is only a RFC. Any suggestions? Thanks. > > Tejun has changed the code in this area and new code will allow you to > introduce this file in blk-throttle.c. All that code is sitting in Jens's > block tree. I am just trying to rebase my patch according to your suggestion, but I can't find the change you mentioned above. So could you please tell me where I can find the related change so that I can base my work on? Thanks Tao > > 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/