linux-serial.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Peter Hurley <peter@hurleysoftware.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.cz>,
	One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
	linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 13/26] locking: Add non-fatal spin lock assert
Date: Thu, 4 Sep 2014 07:14:11 +0200	[thread overview]
Message-ID: <20140904051411.GA27350@gmail.com> (raw)
In-Reply-To: <20140903150729.GA7436@twins.programming.kicks-ass.net>


* Peter Zijlstra <peterz@infradead.org> wrote:

> On Wed, Sep 03, 2014 at 10:50:01AM -0400, Peter Hurley wrote:
> > So a lockdep-only assert is unlikely to draw attention to existing bugs,
> > especially in established drivers.
> 
> By the same logic lockdep will not find locking errors in established
> drivers.

Indeed, this patch is ill-advised in several ways:

  - it extends an API variant that we want to phase

  - emits a warning even if say lockdep has already emitted a
    warning and locking state is not guaranteed to be consistent. 

  - makes the kernel more expensive once fully debugged, in that
    non-fatal checks are unconditional.

Also please submit locking related patches as standalone series 
to the locking subsystem, not embedded in an unrelated series.

Thanks,

	Ingo

  reply	other threads:[~2014-09-04  5:14 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-02 21:39 [PATCH 00/26] tty/serial flow control fixes Peter Hurley
2014-09-02 21:39 ` [PATCH 01/26] Revert "serial: uart: add hw flow control support configuration" Peter Hurley
2014-09-02 21:50   ` Murali Karicheri
2014-09-02 21:58     ` Peter Hurley
2014-09-02 22:17       ` Murali Karicheri
2014-09-02 21:39 ` [PATCH 02/26] serial: Style fix Peter Hurley
2014-09-02 21:39 ` [PATCH 03/26] serial: imx: Fix x_char handling and tx flow control Peter Hurley
2014-09-02 21:39 ` [PATCH 04/26] serial: core: Fix x_char race Peter Hurley
2014-09-02 21:39 ` [PATCH 05/26] serial: core: Remove unsafe x_char optimization Peter Hurley
2014-09-02 21:39 ` [PATCH 06/26] serial: Fix send_xchar() handlers Peter Hurley
2014-09-02 21:39 ` [PATCH 07/26] serial: mpc52xx: Use default serial core x_char handler Peter Hurley
2014-09-02 21:39 ` [PATCH 08/26] serial: sunsab: Don't enable tx if tx stopped Peter Hurley
2014-09-02 21:39 ` [PATCH 09/26] serial: blackfin: Fix missing gpio.h Peter Hurley
2014-09-02 21:39 ` [PATCH 10/26] serial: core: Document lock requirement for UPF_* flags updates Peter Hurley
2014-09-02 21:39 ` [PATCH 11/26] serial: 8250: Document serial8250_modem_status() locking Peter Hurley
2014-09-02 21:39 ` [PATCH 12/26] serial: core: Unwrap tertiary assignment in uart_handle_dcd_change() Peter Hurley
2014-09-02 21:39 ` [PATCH 13/26] locking: Add non-fatal spin lock assert Peter Hurley
2014-09-03  9:27   ` Peter Zijlstra
2014-09-03 11:20     ` Peter Hurley
2014-09-03 14:40       ` Peter Zijlstra
2014-09-03 14:50         ` Peter Hurley
2014-09-03 15:07           ` Peter Zijlstra
2014-09-04  5:14             ` Ingo Molnar [this message]
2014-09-10 11:02               ` Peter Hurley
2014-09-10 13:08                 ` Peter Zijlstra
2014-09-10 14:45                   ` Peter Hurley
2014-09-10 18:34                     ` Greg Kroah-Hartman
2014-09-02 21:39 ` [PATCH 14/26] serial: core: Document and assert lock requirements for irq helpers Peter Hurley
2014-09-02 21:39 ` [PATCH 15/26] serial: core: Privatize modem status enable flags Peter Hurley
2014-09-02 21:39 ` [PATCH 16/26] isdn: i4l: Remove ASYNC_CTS_FLOW Peter Hurley
2014-09-02 21:39 ` [PATCH 17/26] serial: core: Privatize tty->hw_stopped Peter Hurley
2014-09-09  0:29   ` Peter Hurley
2014-09-02 21:39 ` [PATCH 18/26] usb: serial: Remove unused tty->hw_stopped Peter Hurley
2014-09-02 21:39 ` [PATCH 19/26] serial: bfin-uart: Fix auto CTS Peter Hurley
2014-09-02 21:39 ` [PATCH 20/26] serial: core: Use spin_lock_irq() in uart_set_termios() Peter Hurley
2014-09-02 21:39 ` [PATCH 21/26] tty: Convert tty_struct bitfield to bools Peter Hurley
2014-09-03 10:58   ` One Thousand Gnomes
2014-09-03 12:14     ` Peter Hurley
2014-09-03 12:19       ` One Thousand Gnomes
2014-09-03 15:10         ` Peter Hurley
2014-09-03 17:56           ` Greg Kroah-Hartman
2014-09-04 16:08             ` Peter Hurley
2014-09-02 21:39 ` [PATCH 22/26] tty: Serialize tty flow control changes with flow_lock Peter Hurley
2014-09-02 21:39 ` [PATCH 23/26] tty: Move packet mode flow control notifications to pty driver Peter Hurley
2014-09-02 21:39 ` [PATCH 24/26] tty: Serialize tcflow() with other tty flow control changes Peter Hurley
2014-09-02 21:39 ` [PATCH 25/26] tty: Move and rename send_prio_char() as tty_send_xchar() Peter Hurley
2014-09-02 21:39 ` [PATCH 26/26] tty: Hold termios_rwsem for tcflow(TCIxxx) Peter Hurley
2014-09-08 23:24 ` [PATCH 00/26] tty/serial flow control fixes Greg Kroah-Hartman
2014-09-08 23:33   ` Peter Hurley
2014-09-08 23:43     ` Greg Kroah-Hartman
2014-09-08 23:46       ` Peter Hurley
2014-09-09  0:01         ` Greg Kroah-Hartman
2014-09-10 19:06 ` [PATCH v2 00/14] " Peter Hurley
2014-09-10 19:06   ` [PATCH v2 01/14] serial: core: Document and assert lock requirements for irq helpers Peter Hurley
2014-09-10 19:06   ` [PATCH v2 02/14] serial: core: Privatize modem status enable flags Peter Hurley
2014-09-10 19:06   ` [PATCH v2 03/14] isdn: i4l: Remove ASYNC_CTS_FLOW Peter Hurley
2014-09-10 19:06   ` [PATCH v2 04/14] serial: core: Privatize tty->hw_stopped Peter Hurley
2014-09-10 19:06   ` [PATCH v2 05/14] usb: serial: Remove unused tty->hw_stopped Peter Hurley
2014-09-23 15:33     ` Johan Hovold
2014-09-10 19:06   ` [PATCH v2 06/14] serial: bfin-uart: Fix auto CTS Peter Hurley
2014-09-10 19:06   ` [PATCH v2 07/14] serial: core: Use spin_lock_irq() in uart_set_termios() Peter Hurley
2014-09-10 19:06   ` [PATCH v2 08/14] tty: Convert tty_struct bitfield to ints Peter Hurley
2014-09-10 19:06   ` [PATCH v2 09/14] tty: Serialize tty flow control changes with flow_lock Peter Hurley
2014-09-10 19:06   ` [PATCH v2 10/14] tty: Move packet mode flow control notifications to pty driver Peter Hurley
2014-09-10 19:06   ` [PATCH v2 11/14] tty: Serialize tcflow() with other tty flow control changes Peter Hurley
2014-09-10 19:06   ` [PATCH v2 12/14] tty: Move and rename send_prio_char() as tty_send_xchar() Peter Hurley
2014-09-10 19:06   ` [PATCH v2 13/14] tty: Hold termios_rwsem for tcflow(TCIxxx) Peter Hurley
2014-09-10 19:06   ` [PATCH v2 14/14] tty: Workaround Alpha non-atomic byte storage in tty_struct Peter Hurley

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=20140904051411.GA27350@gmail.com \
    --to=mingo@kernel.org \
    --cc=gnomes@lxorguk.ukuu.org.uk \
    --cc=gregkh@linuxfoundation.org \
    --cc=jslaby@suse.cz \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=peter@hurleysoftware.com \
    --cc=peterz@infradead.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;
as well as URLs for NNTP newsgroup(s).