From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753474Ab1ASGIs (ORCPT ); Wed, 19 Jan 2011 01:08:48 -0500 Received: from cpoproxy1-pub.bluehost.com ([69.89.21.11]:45411 "HELO cpoproxy1-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750968Ab1ASGIr (ORCPT ); Wed, 19 Jan 2011 01:08:47 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=tao.ma; h=Received:Message-ID:Date:From:User-Agent:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=bAlBA2ofvNHbYqvFfdIq9M5UWsgJ/M5N/WojARGIiVVtQkLSho4gP9RnqoHndevsB2t3q+IoAKAv5AnxYbgKfMlDr6oV4zJXcWPcMuVIVU4gCOtpK+eEf1Dr8O+rY/pV; Message-ID: <4D367FFF.2020505@tao.ma> Date: Wed, 19 Jan 2011 14:09:03 +0800 From: Tao Ma User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: Jens Axboe CC: linux-kernel@vger.kernel.org, Steven Rostedt , Jeff Moyer Subject: Re: [PATCH v2] blktrace: Don't output messages if NOTIFY isn't set. References: <1295406590-7320-1-git-send-email-tm@tao.ma> <4D367873.90805@kernel.dk> In-Reply-To: <4D367873.90805@kernel.dk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Identified-User: {1390:box585.bluehost.com:colyli:tao.ma} {sentby:smtp auth 114.251.86.0 authed with tm@tao.ma} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/19/2011 01:36 PM, Jens Axboe wrote: > On 2011-01-18 20:09, Tao Ma wrote: >> Hi Jeff, >> On 01/18/2011 11:50 PM, Jeff Moyer wrote: >>> Tao Ma writes: >>> >>>> + /* >>>> + * If the user does specify some action masks, don't send any note >>>> + * message to the trace so that it won't pollute what the user really >>>> + * want to see. >>>> + */ >>>> + if (bt->act_mask != (u16) -1) >>>> + return; >>>> + >>> >>> I think you want to check for the BLK_TC_NOTIFY bit. >> I was thinking of this, but actually there is no way for the user to set this flag. >> At least from blktrace(8), -a doesn't have any flags like NOTIFY. So if the user >> set any flag, NOTIFY will be cleared. So it does work. Thanks. >> >> Here is the updated patch. >> >> From 8693c19f165b09f60d5c26aed369d79a79e144ba Mon Sep 17 00:00:00 2001 >> From: Tao Ma >> Date: Wed, 19 Jan 2011 10:51:44 +0800 >> Subject: [PATCH v2] blktrace: Don't output messages if NOTIFY isn't set. >> >> Now if we enable blktrace, cfq has too many messages output to the >> trace buffer. It is fine if we don't specify any action mask. >> But if I do like this: >> blktrace /dev/sdb -a issue -a complete -o - | blkparse -i - >> I only want to see 'D' and 'C', while with the following command >> dd if=/mnt/ocfs2/test of=/dev/null bs=4k count=1 iflag=direct >> >> I will get(with a 2.6.37 vanilla kernel): >> 8,16 0 0 0.000000000 0 m N cfq3805 alloced >> 8,16 0 0 0.000004126 0 m N cfq3805 insert_request >> 8,16 0 0 0.000004884 0 m N cfq3805 add_to_rr >> 8,16 0 0 0.000008417 0 m N cfq workload slice:300 >> 8,16 0 0 0.000009557 0 m N cfq3805 set_active wl_prio:0 wl_type:2 >> 8,16 0 0 0.000010640 0 m N cfq3805 fifo= (null) >> 8,16 0 0 0.000011193 0 m N cfq3805 dispatch_insert >> 8,16 0 0 0.000012221 0 m N cfq3805 dispatched a request >> 8,16 0 0 0.000012802 0 m N cfq3805 activate rq, drv=1 >> 8,16 0 1 0.000013181 3805 D R 114759 + 8 [dd] >> 8,16 0 2 0.000164244 0 C R 114759 + 8 [0] >> 8,16 0 0 0.000167997 0 m N cfq3805 complete rqnoidle 0 >> 8,16 0 0 0.000168782 0 m N cfq3805 set_slice=100 >> 8,16 0 0 0.000169874 0 m N cfq3805 arm_idle: 8 group_idle: 0 >> 8,16 0 0 0.000170189 0 m N cfq schedule dispatch >> 8,16 0 0 0.000397938 0 m N cfq3805 slice expired t=0 >> 8,16 0 0 0.000399763 0 m N cfq3805 sl_used=1 disp=1 charge=1 iops=0 sect=8 >> 8,16 0 0 0.000400227 0 m N cfq3805 del_from_rr >> 8,16 0 0 0.000400882 0 m N cfq3805 put_queue >> >> See, there are 19 lines while I only need 2. I don't think it is >> appropriate for a user. >> >> So this patch will disable any messages if the BLK_TC_NOTIFY isn't set. >> Now the output for the same command will look like: >> 8,16 0 1 0.000000000 4908 D R 114759 + 8 [dd] >> 8,16 0 2 0.000146827 0 C R 114759 + 8 [0] >> >> Yes, it is what I want to see. >> >> Cc: Jens Axboe >> Cc: Steven Rostedt >> Cc: Jeff Moyer >> Signed-off-by: Tao Ma >> --- >> kernel/trace/blktrace.c | 7 +++++++ >> 1 files changed, 7 insertions(+), 0 deletions(-) >> >> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c >> index 153562d..d95721f 100644 >> --- a/kernel/trace/blktrace.c >> +++ b/kernel/trace/blktrace.c >> @@ -138,6 +138,13 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...) >> !blk_tracer_enabled)) >> return; >> >> + /* >> + * If the BLK_TC_NOTIFY action mask isn't set, don't send any note >> + * message to the trace. >> + */ >> + if (!(bt->act_mask& BLK_TC_NOTIFY)) >> + return; >> + >> local_irq_save(flags); >> buf = per_cpu_ptr(bt->msg_data, smp_processor_id()); >> va_start(args, fmt); > > Hmm, it should only mask messages, not task/timestamp notifies. This > will mask all of them. uh, yes, that's the reason why I put the check in __trace_note_message, not in trace_note. trace_note_time and trace_note_tsk will handle time/task issue and then call trace_note with the appropriate action mask. Do I miss something here? > > The message mask I agree with, but the other ones should essentially be > unmaskable. yeah, agree. Regards, Tao