Re: [PATCH] netconsole: queue console messages to send later

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From: David Miller
Date: Monday, June 7, 2010 - 4:50 pm

From: Flavio Leitner <fleitner@redhat.com>
Date: Mon,  7 Jun 2010 16:24:52 -0300


You absolutely and positively MUST NOT do this.  Otherwise netconsole
becomes completely useless.  Your idea has been proposed several times
as far back as 6 years ago, it was unacceptable then and it's
unacceptable now.

The whole point of netconsole is that we may be deep in an interrupt
or other atomic context, the machine is about to hard hang, and it's
absolutely essential that we get out any and all kernel logging
messages that we can, immediately.

There may not be another timer or workqueue able to execute after the
printk() we're trying to emit.  We may never get to that point.

So if we defer messages, that means we won't get the message and we
won't be able to debug the problem.

Fix the locking in the drivers or layers that cause the issue instead
of breaking netconsole.
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Messages in current thread:
[v5 Patch 2/3] bridge: make bridge support netpoll, Amerigo Wang, (Wed May 5, 1:11 am)
[v5 Patch 3/3] bonding: make bonding support netpoll, Amerigo Wang, (Wed May 5, 1:11 am)
[PATCH] netconsole: queue console messages to send later, Flavio Leitner, (Mon Jun 7, 12:24 pm)
Re: [PATCH] netconsole: queue console messages to send later, Stephen Hemminger, (Mon Jun 7, 1:00 pm)
Re: [PATCH] netconsole: queue console messages to send later, David Miller, (Mon Jun 7, 4:50 pm)