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From:   Chen Zhongjin <chenzhongjin@huawei.com>
To:     <linux-kernel@vger.kernel.org>, <linux-perf-users@vger.kernel.org>
CC:     <peterz@infradead.org>, <mingo@redhat.com>, <acme@kernel.org>,
        <mark.rutland@arm.com>, <alexander.shishkin@linux.intel.com>,
        <jolsa@kernel.org>, <namhyung@kernel.org>, <irogers@google.com>,
        <john.garry@huawei.com>, <adrian.hunter@intel.com>,
        <ak@linux.intel.com>, <florian.fischer@muhq.space>,
        <chenzhongjin@huawei.com>
Subject: [PATCH -next 1/5] perf: Fix show_arg_names not working for tp arg names
Date:   Mon, 26 Sep 2022 11:14:36 +0800
Message-ID: <20220926031440.28275-2-chenzhongjin@huawei.com>
In-Reply-To: <20220926031440.28275-1-chenzhongjin@huawei.com>
References: <20220926031440.28275-1-chenzhongjin@huawei.com>
MIME-Version: 1.0
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trace__fprintf_tp_fields() will always print arg names because when
implemented it is forced to print arg_names with:
(1 || trace->show_arg_names)

So the printing looks like:

> cat ~/.perfconfig
    [trace]
        show_arg_names = no

> perf trace -e syscalls:*mmap sleep 1
    0.000 sleep/1119 syscalls:sys_enter_mmap(NULL, 8192, READ|WRITE, PRIVATE|ANONYMOUS)
    0.179 sleep/1119 syscalls:sys_exit_mmap(__syscall_nr: 9, ret: 140535426170880)
    ...

Although the comment said that perhaps we need a show_tp_arg_names.
I don't think it's necessary to control them separately because
it's not so clean that part of the log shows arg names but other not.
Also when we are tracing functions it's rare to especially distinguish
syscalls and tp trace.

Only use one option to control arg names printing is more resonable
and simple. So remove the force condition and commit.

After fix:

> perf trace -e syscalls:*mmap sleep 1
    0.000 sleep/1121 syscalls:sys_enter_mmap(NULL, 8192, READ|WRITE, PRIVATE|ANONYMOUS)
    0.163 sleep/1121 syscalls:sys_exit_mmap(9, 140454467661824)
    ...

Fixes: f11b2803bb88 ("perf trace: Allow choosing how to augment the tracepoint arguments")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
---
 tools/perf/builtin-trace.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 0bd9d01c0df9..c7bb7a8222a6 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2762,11 +2762,7 @@ static size_t trace__fprintf_tp_fields(struct trace *trace, struct evsel *evsel,
 
 		printed += scnprintf(bf + printed, size - printed, "%s", printed ? ", " : "");
 
-		/*
-		 * XXX Perhaps we should have a show_tp_arg_names,
-		 * leaving show_arg_names just for syscalls?
-		 */
-		if (1 || trace->show_arg_names)
+		if (trace->show_arg_names)
 			printed += scnprintf(bf + printed, size - printed, "%s: ", field->name);
 
 		printed += syscall_arg_fmt__scnprintf_val(arg, bf + printed, size - printed, &syscall_arg, val);
-- 
2.17.1