From: Taeung Song <treeze.taeung@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: [PATCH RESEND 1/3] tracing/syscalls: Rename variable 'nr' to 'syscall_nr'
Date: Fri, 26 Feb 2016 02:26:58 +0900 [thread overview]
Message-ID: <56CF3962.9060400@gmail.com> (raw)
In-Reply-To: <20160225120907.0a30d792@gandalf.local.home>
On 02/26/2016 02:09 AM, Steven Rostedt wrote:
> On Thu, 25 Feb 2016 12:05:01 -0500
> Steven Rostedt <rostedt@goodmis.org> wrote:
>
>> On Fri, 26 Feb 2016 01:53:47 +0900
>> Taeung Song <treeze.taeung@gmail.com> wrote:
>>
>>>
>>> The underlying cause of this problem is not because of
>>> the python script. This problem have relevance to tracing/syscalls
>>> as below.
>>>
>>> # cat
>>> /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
>>> name: sys_enter_io_getevents
>>> ID: 739
>>> format:
>>> field:unsigned short common_type; offset:0;size:2;signed:0;
>>> field:unsigned char common_flags; offset:2;size:1;signed:0;
>>> field:unsigned char common_preempt_count; offset:3;size:1;signed:0;
>>> field:int common_pid; offset:4;size:4;signed:1;
>>> field:int nr; offset:8;size:4;signed:1;
>>> field:aio_context_t ctx_id; offset:16;size:8;signed:0;
>>> field:long min_nr; offset:24;size:8;signed:0;
>>> field:long nr; offset:32;size:8;signed:0;
>>> field:struct io_event * events; offset:40;size:8;signed:0;
>>> field:struct timespec * timeout; offset:48;size:8;signed:0;
>>>
>>> print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events:
>>> 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned
>>> long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned
>>> long)(REC->events)), ((unsigned long)(REC->timeout))
>>>
>>>
>>> As you see, there are duplicated variable name among fields.
>>> So I renamed the variable name 'nr' to 'syscall_nr' to avoid this
>>> duplication. As you know 'nr' in print_syscall_enter() mean
>>> system call number so, I changed 'nr' to 'syscall_nr'(IMHO).
>>>
>>
>> The above should have been in the change log. That makes much more
>> sense.
>>
Sorry, this change log is misinterpretable.
So I'm rewriting change log for this patch.
I will resend it soon.
>
> I'm a bit nervous about this change though. Because it is an ABI
> change. Hopefully there's no tools that parse the syscall tracepoints
> and expect to find a 'nr' in there.
>
AFIAIK, I think so but resend this modified patch.
Thanks,
Taeung
prev parent reply other threads:[~2016-02-25 17:27 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-25 15:24 [PATCH RESEND 1/3] tracing/syscalls: Rename variable 'nr' to 'syscall_nr' Taeung Song
2016-02-25 15:47 ` Steven Rostedt
2016-02-25 16:53 ` Taeung Song
2016-02-25 17:05 ` Steven Rostedt
2016-02-25 17:09 ` Steven Rostedt
2016-02-25 17:26 ` Taeung Song [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=56CF3962.9060400@gmail.com \
--to=treeze.taeung@gmail.com \
--cc=acme@kernel.org \
--cc=jiangshanlai@gmail.com \
--cc=jolsa@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox