From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932705AbcEKQuL (ORCPT ); Wed, 11 May 2016 12:50:11 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:31667 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932074AbcEKQuI (ORCPT ); Wed, 11 May 2016 12:50:08 -0400 Date: Wed, 11 May 2016 09:49:56 -0700 From: Shaohua Li To: Jeff Moyer CC: , , Steven Rostedt , , Subject: Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled Message-ID: <20160511164945.GA83519@devbig084.prn1.facebook.com> References: <2c3ee532132f8925dd0be1178e8dee0bba6b448c.1462838969.git.shli@fb.com> <20160511002004.GA2293701@devbig084.prn1.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-12-10) X-Originating-IP: [192.168.52.123] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-05-11_05:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 11, 2016 at 09:41:20AM -0400, Jeff Moyer wrote: > Shaohua Li writes: > > > On Tue, May 10, 2016 at 11:52:15AM -0400, Jeff Moyer wrote: > >> Shaohua Li writes: > >> > >> > if trace isn't enabled, parsing cgroup path just wastes cpu > >> > > >> > Signed-off-by: Shaohua Li > >> > --- > >> > block/blk-throttle.c | 5 ++--- > >> > include/linux/blktrace_api.h | 9 +++++++++ > >> > 2 files changed, 11 insertions(+), 3 deletions(-) > >> > > >> > diff --git a/block/blk-throttle.c b/block/blk-throttle.c > >> > index 2149a1d..47a3e54 100644 > >> > --- a/block/blk-throttle.c > >> > +++ b/block/blk-throttle.c > >> > @@ -211,15 +211,14 @@ static struct throtl_data *sq_to_td(struct throtl_service_queue *sq) > >> > * > >> > * The messages are prefixed with "throtl BLKG_NAME" if @sq belongs to a > >> > * throtl_grp; otherwise, just "throtl". > >> > - * > >> > - * TODO: this should be made a function and name formatting should happen > >> > - * after testing whether blktrace is enabled. > >> > >> You've only addressed the second part of the TODO, please don't remove > >> the first part. > > > > alright, I'll send a patch to convert it to a function. > > Heh. I figured you'd just put that part of the TODO back in there. But > actually addressing it sounds better. ;-) Actually I'd like to give up. To convert it to a function, I need add a var arg version of blk_add_trace_msg. And throtl_log adds new parameter and change fmt, so I must allocate a new string to fit old fmt and new parameter and new fmt string. It's not worthy the effort I think. Thanks, Shaohua