From: Andrew Morton <akpm@linux-foundation.org>
To: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: gregkh@suse.de, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv3 1/1] sysfs: add more info to the oops dump
Date: Thu, 10 Mar 2011 14:38:06 -0800 [thread overview]
Message-ID: <20110310143806.7542e929.akpm@linux-foundation.org> (raw)
In-Reply-To: <1299796027-3343-2-git-send-email-ext-phil.2.carmody@nokia.com>
On Fri, 11 Mar 2011 00:27:07 +0200
Phil Carmody <ext-phil.2.carmody@nokia.com> wrote:
> +static int last_sysfs_write_len;
> void sysfs_printk_last_file(void)
> {
> - printk(KERN_EMERG "last sysfs file: %s\n", last_sysfs_file);
> + printk(KERN_EMERG "last sysfs file (%c): %s%c",
> + (last_sysfs_write_len == SYSFS_NOT_A_WRITE) ? 'r' : 'w',
> + last_sysfs_file,
> + last_sysfs_write_len > 0 ? ' ' : '\n');
> + if (last_sysfs_write_len >= (int)sizeof(last_sysfs_write))
> + printk(KERN_CONT " written: %s...(%d chars)\n",
> + last_sysfs_write, last_sysfs_write_len);
> + else if (last_sysfs_write_len > 0)
> + printk(KERN_CONT " written: %s\n", last_sysfs_write);
> }
That's going to fail to emit the \n if last_sysfs_write_len<=0.
However there are tricks inside printk() which will fix that up if the
next printk starts with KERN_foo.
I can recall just one instance in the past 5-6 years in which the
last-sysfs-file output enabled me to locate a bug which would otherwise
have been unlocatable (within a drivers/md handler, iirc).
I don't think it's a terribly useful feature. Except for when it _is_
useful, when it's very useful ;) The world wouldn't end if we decided
to remove it.
next prev parent reply other threads:[~2011-03-10 22:38 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-10 15:53 [PATCH 1/1] sysfs: add more info to the oops dump Phil Carmody
2011-03-10 16:25 ` Greg KH
2011-03-10 18:32 ` Phil Carmody
2011-03-10 19:02 ` Greg KH
2011-03-10 21:10 ` Phil Carmody
2011-03-10 21:27 ` Greg KH
2011-03-10 22:27 ` [PATCHv3 0/1] " Phil Carmody
2011-03-10 22:27 ` [PATCHv3 1/1] " Phil Carmody
2011-03-10 22:38 ` Andrew Morton [this message]
2011-03-10 22:59 ` Thomas Gleixner
2011-03-10 23:03 ` Greg KH
2011-03-10 23:15 ` Andrew Morton
2011-03-10 23:06 ` Phil Carmody
2011-03-10 23:13 ` Thomas Gleixner
2011-03-10 23:22 ` Andrew Morton
2011-03-10 23:27 ` Thomas Gleixner
2011-03-10 23:46 ` Thomas Gleixner
2011-03-10 23:22 ` Phil Carmody
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