From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758317AbZDODCU (ORCPT ); Tue, 14 Apr 2009 23:02:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752828AbZDODCI (ORCPT ); Tue, 14 Apr 2009 23:02:08 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:62079 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753604AbZDODCH (ORCPT ); Tue, 14 Apr 2009 23:02:07 -0400 Message-ID: <49E54E60.50408@cn.fujitsu.com> Date: Wed, 15 Apr 2009 11:02:56 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Ingo Molnar CC: Jens Axboe , "Theodore Ts'o" , Arnaldo Carvalho de Melo , Frederic Weisbecker , Steven Rostedt , LKML Subject: [PATCH] blktrace: fix context-info when mixed-using blk tracer and trace events Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When set current tracer to blk tracer, TRACE_ITER_CONTEXT_INFO is unset, but actually context-info is printed: pdflush-431 [000] 821.181576: 8,0 P N [pdflush] And then if we enable TRACE_ITER_CONTEXT_INFO: # echo context-info > trace_options We'll see context-info is printed twice. What's worse is, when use blk tracer and trace events at a time, we'll see no context-info for trace events: jbd2_commit_logging: dev dm-0:8 transaction 333227 jbd2_end_commit: dev dm-0:8 transaction 333227 head 332814 rm-25433 [001] 9578.307485: 8,18 m N cfq25433 slice expired t=0 rm-25433 [001] 9578.307486: 8,18 m N cfq25433 put_queue This patch adds blk_tracer->set_flags(), and context-info flag is unset only when we set the output to classic mode. Note after this patch, one should unset context-info explicitly if he wants to get binary output that can be parsed by blkparse: # echo nocontext-info > trace_options # echo bin > trace_options # echo blk > current_tracer # cat trace_pipe | blkparse -i - Reported-by: Theodore Ts'o Signed-off-by: Li Zefan --- kernel/trace/blktrace.c | 18 +++++++++++++----- 1 files changed, 13 insertions(+), 5 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 8e7c5da..c32062b 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1211,7 +1211,6 @@ static void blk_tracer_print_header(struct seq_file *m) static void blk_tracer_start(struct trace_array *tr) { blk_tracer_enabled = true; - trace_flags &= ~TRACE_ITER_CONTEXT_INFO; } static int blk_tracer_init(struct trace_array *tr) @@ -1224,7 +1223,6 @@ static int blk_tracer_init(struct trace_array *tr) static void blk_tracer_stop(struct trace_array *tr) { blk_tracer_enabled = false; - trace_flags |= TRACE_ITER_CONTEXT_INFO; } static void blk_tracer_reset(struct trace_array *tr) @@ -1289,9 +1287,6 @@ out: static enum print_line_t blk_trace_event_print(struct trace_iterator *iter, int flags) { - if (!trace_print_context(iter)) - return TRACE_TYPE_PARTIAL_LINE; - return print_one_line(iter, false); } @@ -1326,6 +1321,18 @@ static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter) return print_one_line(iter, true); } +static int blk_tracer_set_flag(u32 old_flags, u32 bit, int set) +{ + /* don't output context-info for blk_classic output */ + if (bit == TRACE_BLK_OPT_CLASSIC) { + if (set) + trace_flags &= ~TRACE_ITER_CONTEXT_INFO; + else + trace_flags |= TRACE_ITER_CONTEXT_INFO; + } + return 0; +} + static struct tracer blk_tracer __read_mostly = { .name = "blk", .init = blk_tracer_init, @@ -1335,6 +1342,7 @@ static struct tracer blk_tracer __read_mostly = { .print_header = blk_tracer_print_header, .print_line = blk_tracer_print_line, .flags = &blk_tracer_flags, + .set_flag = blk_tracer_set_flag, }; static struct trace_event trace_blk_event = { -- 1.5.4.rc3