From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
Jiri Slaby <jslaby@suse.cz>,
linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org
Subject: Re: [PATCH tty-next 7/7] n_tty: trace input/read flow control
Date: Tue, 26 Nov 2013 08:00:35 -0500 [thread overview]
Message-ID: <52949B73.3000206@hurleysoftware.com> (raw)
In-Reply-To: <529166C0.8040001@hurleysoftware.com>
On 11/23/2013 09:38 PM, Peter Hurley wrote:
> On 11/23/2013 07:25 PM, One Thousand Gnomes wrote:
>> On Fri, 22 Nov 2013 10:59:25 -0500
>> Peter Hurley <peter@hurleysoftware.com> wrote:
>>
>>> Instrument .receive_buf() and read() paths with trace_printk's
>>> to aid in debugging flow control changes.
>>
>> tty devices have a device, we have a dev_dbg() layer. The old tty trace
>> predates this but there isn't really any excuse for not using it now that
>> I can see ?
>
> I was using the ftrace facility because it has significantly less performance
> impact than printk (which was an important factor while debugging flow control
> problems).
>
> That said, I could further macro-ize n_tty_trace() with selectable facility
> (which would be useful when debugging problems that end in cpu death).
Greg,
I don't really mind if you don't want to take this patch; it is useful but
it does clutter up the code.
Regards,
Peter Hurley
next prev parent reply other threads:[~2013-11-26 13:00 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-22 15:59 [PATCH tty-next 0/7] n_tty cleanup + trace additions Peter Hurley
2013-11-22 15:59 ` [PATCH tty-next 1/7] n_tty: Merge .receive_buf() flavors Peter Hurley
2013-11-22 15:59 ` [PATCH tty-next 2/7] n_tty: Un-inline slow-path n_tty_receive_char() Peter Hurley
2013-11-22 15:59 ` [PATCH tty-next 3/7] n_tty: Un-inline slow-path n_tty_receive_char_closing() Peter Hurley
2013-11-22 15:59 ` [PATCH tty-next 4/7] n_tty: Refactor PARMRK doubling checks Peter Hurley
2013-11-22 15:59 ` [PATCH tty-next 5/7] n_tty: Refactor input_available_p() by call site Peter Hurley
2013-11-24 0:22 ` One Thousand Gnomes
2013-11-24 0:26 ` One Thousand Gnomes
2013-11-24 2:01 ` Peter Hurley
2013-11-24 16:18 ` One Thousand Gnomes
2013-11-22 15:59 ` [PATCH tty-next 6/7] n_tty: Only perform wakeups for waiters Peter Hurley
2013-11-24 0:23 ` One Thousand Gnomes
2013-11-24 2:29 ` Peter Hurley
2013-11-22 15:59 ` [PATCH tty-next 7/7] n_tty: trace input/read flow control Peter Hurley
2013-11-24 0:25 ` One Thousand Gnomes
2013-11-24 2:38 ` Peter Hurley
2013-11-26 13:00 ` Peter Hurley [this message]
2013-12-02 19:24 ` [PATCH v2 tty-next 0/8] n_tty cleanup + trace additions Peter Hurley
2013-12-02 19:24 ` [PATCH v2 tty-next 1/8] n_tty: Merge .receive_buf() flavors Peter Hurley
2013-12-02 19:24 ` [PATCH v2 tty-next 2/8] n_tty: Un-inline slow-path n_tty_receive_char() Peter Hurley
2013-12-02 19:24 ` [PATCH v2 tty-next 3/8] n_tty: Un-inline slow-path n_tty_receive_char_closing() Peter Hurley
2013-12-02 19:24 ` [PATCH v2 tty-next 4/8] n_tty: Refactor PARMRK doubling checks Peter Hurley
2013-12-02 19:24 ` [PATCH v2 tty-next 5/8] n_tty: Refactor input_available_p() by call site Peter Hurley
2013-12-02 19:24 ` [PATCH v2 tty-next 6/8] n_tty: Only perform wakeups for waiters Peter Hurley
2013-12-02 19:24 ` [PATCH v2 tty-next 7/8] n_tty: Extend debug tracing Peter Hurley
2013-12-09 0:54 ` Greg Kroah-Hartman
2013-12-02 19:24 ` [PATCH v2 tty-next 8/8] n_tty: Trace echo output with separate trace configuration Peter Hurley
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