linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@transmeta.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Brownell <david-b@pacbell.net>,
	Matthew Dharm <mdharm-kernel@one-eyed-alien.net>,
	Greg KH <greg@kroah.com>, <linux-usb-devel@lists.sourceforge.net>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [linux-usb-devel] Re: [BK PATCH] USB changes for 2.5.34
Date: Tue, 10 Sep 2002 12:03:00 -0700 (PDT)	[thread overview]
Message-ID: <Pine.LNX.4.44.0209101156510.7106-100000@home.transmeta.com> (raw)
In-Reply-To: <1031683480.31787.107.camel@irongate.swansea.linux.org.uk>


On 10 Sep 2002, Alan Cox wrote:
> 
> It drops you politely into the kernel debugger, you fix up the values
> and step over it. If you want to debug with zen mind power and printk
> feel free. For the rest of us BUG() is fine on SMP

Ok, a show of hands.. 

Of the millions (whatever) of Linux machines, how many have a kernel 
debugger attached? Count them.

In other words, if a user is faced with a dead machine with no other way
to even know what BUG() triggered than to try to set up a cross debugger,
just how useful is that BUG()? I claim it is pretty useless - simply
because 99+% of all people won't even make a bug report in that case,
they'll just push the reset button and consider Linux unreliable.

In other news, the approach that shows up in the kernel logs might just 
eventually be noticed and acted upon (especially if the machine acts 
strange and kills processes).

So I claim a BUG() that locks up the machine is useless. If the user can't
just run ksymoops and email out the BUG message, that BUG() is _not_ fine
on SMP.

It has nothing to do with zen mind power or printk's. It has everything to 
do with the fact that a working machine is about a million times easier to 
debug on than a dead one, _and_ is a lot more likely to get acted upon by 
most users.

		Linus


  reply	other threads:[~2002-09-10 18:58 UTC|newest]

Thread overview: 99+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-09-09 22:17 [BK PATCH] USB changes for 2.5.34 Greg KH
2002-09-10  0:17 ` Linus Torvalds
2002-09-10  0:19   ` Greg KH
2002-09-10  0:30     ` Linus Torvalds
2002-09-10  0:40       ` [linux-usb-devel] " Alan Cox
2002-09-10  1:41         ` Linus Torvalds
2002-09-10  1:48           ` Linus Torvalds
2002-09-10 10:23     ` Andries Brouwer
2002-09-10  0:35   ` Nicholas Miell
2002-09-10  1:01     ` [patch] dump_stack(): arch-neutral stack trace Andrew Morton
2002-09-15  4:34       ` Daniel Phillips
2002-09-15  4:51         ` Andrew Morton
2002-09-10  1:27     ` [BK PATCH] USB changes for 2.5.34 Linus Torvalds
2002-09-10  2:07   ` Matthew Dharm
2002-09-10  2:49     ` Linus Torvalds
2002-09-10  2:59       ` Linus Torvalds
2002-09-10 16:32       ` [linux-usb-devel] " David Brownell
2002-09-10 16:51         ` Linus Torvalds
2002-09-10 17:16           ` Jeff Garzik
2002-09-10 18:16             ` David S. Miller
2002-09-10 18:40               ` Linus Torvalds
2002-09-10 18:48                 ` Jeff Garzik
2002-09-10 19:31                 ` David S. Miller
2002-09-10 19:32                 ` Oliver Xymoron
2002-09-10 19:38                   ` Linus Torvalds
2002-09-10 19:43                     ` Jeff Garzik
2002-09-10 21:52                   ` Bill Davidsen
2002-09-10 22:02                     ` Jeff Garzik
2002-09-10 18:44           ` Alan Cox
2002-09-10 19:03             ` Linus Torvalds [this message]
2002-09-10 19:27               ` Rik van Riel
2002-09-10 20:18                 ` Alan Cox
2002-09-10 22:00                 ` David Woodhouse
2002-09-10 22:23                   ` Alan Cox
2002-09-10 22:26                   ` David Woodhouse
2002-09-10 23:01                     ` Alan Cox
2002-09-10 19:29               ` David S. Miller
2002-09-15  5:10               ` Daniel Phillips
2002-09-15  5:33                 ` Daniel Berlin
2002-09-15 16:41                   ` Daniel Phillips
2002-09-16  0:32                     ` Horst von Brand
2002-09-15  6:07                 ` Pete Zaitcev
2002-09-15  7:00                   ` Andrew Morton
2002-09-15 14:53                   ` Daniel Phillips
2002-09-15 18:23                     ` Pete Zaitcev
2002-09-15 18:34                       ` Jeff Garzik
2002-09-16  0:55                         ` Larry McVoy
2002-09-15 20:05                   ` David Woodhouse
2002-09-15 21:35                   ` Rob Landley
2002-09-16  3:00                     ` Larry McVoy
2002-09-16  3:08                       ` Daniel Phillips
2002-09-16 11:16                       ` Henning P. Schmiedehausen
2002-09-16 18:35                       ` Thunder from the hill
2002-09-16 18:45                         ` Daniel Phillips
2002-09-16 19:36                           ` Thunder from the hill
2002-09-16 19:40                             ` Daniel Phillips
2002-09-16  8:50                     ` Ian Molton
2002-09-16  9:37                       ` Rob Landley
2002-09-15 18:06                 ` Linus Torvalds
2002-09-15 18:36                   ` Roman Zippel
2002-09-15 19:04                   ` Daniel Jacobowitz
2002-09-15 19:43                     ` Andrew Morton
2002-09-15 19:43                       ` Daniel Phillips
2002-09-15 23:24                     ` Larry McVoy
2002-09-15 23:41                       ` Daniel Jacobowitz
2002-09-15 23:52                         ` Larry McVoy
2002-09-16  0:01                           ` Robert Love
2002-09-16  1:29                           ` Alan Cox
2002-09-16  2:13                             ` Larry McVoy
2002-09-16 11:05                               ` Henning P. Schmiedehausen
2002-09-16 14:05                               ` Rogier Wolff
2002-09-16 16:24                               ` Marco Colombo
2002-09-16  0:44                       ` Daniel Phillips
2002-09-16  1:23                       ` Alan Cox
2002-09-15 19:07                   ` Daniel Phillips
2002-09-16  9:06                     ` Jens Axboe
2002-09-16 15:15                       ` Daniel Phillips
2002-09-16 15:59                         ` kernel debuggers was [Re: [linux-usb-devel] Re: [BK PATCH] USB changes for 2.5.34] Soewono Effendi
2002-09-16 14:14                     ` [linux-usb-devel] Re: [BK PATCH] USB changes for 2.5.34 David Woodhouse
2002-09-16 14:53                       ` Jens Axboe
2002-09-15 19:08                   ` Linus Torvalds
2002-09-15 19:10                     ` Daniel Phillips
2002-09-15 19:26                       ` Linus Torvalds
2002-09-15 19:32                         ` Daniel Jacobowitz
2002-09-15 19:48                           ` Daniel Phillips
2002-09-16  4:59                             ` Jeff Dike
2002-09-16  4:05                               ` Daniel Phillips
2002-09-16  4:55                           ` Jeff Dike
2002-09-15 19:35                         ` Daniel Phillips
2002-09-16  4:51                       ` Jeff Dike
2002-09-16 15:29                     ` Oliver Xymoron
2002-09-18  0:33                   ` Rusty Russell
2002-09-18  0:46                     ` Linus Torvalds
2002-09-18  0:50                       ` Daniel Phillips
2002-09-18  1:16                         ` Rik van Riel
2002-09-15 13:54               ` Rogier Wolff
2002-09-15  5:01           ` Daniel Phillips
2002-09-10 16:46       ` Thunder from the hill
2002-09-10 16:56         ` Vojtech Pavlik

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=Pine.LNX.4.44.0209101156510.7106-100000@home.transmeta.com \
    --to=torvalds@transmeta.com \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=david-b@pacbell.net \
    --cc=greg@kroah.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb-devel@lists.sourceforge.net \
    --cc=mdharm-kernel@one-eyed-alien.net \
    /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).