Re: [PATCH v6 2/2] Output stall data in debugfs

From: Andi Kleen
Date: Thu Aug 11 2011 - 14:48:29 EST

Alex Neronskiy <zakmagnus@xxxxxxxxxxxx> writes:

> From: Alex Neronskiy <zakmagnus@xxxxxxxxxxxx>
> Instead of using the log, use debugfs for output of both stall
> lengths and stack traces. Printing to the log can result in
> watchdog touches,

Why? Because of printk being slow or something else?

The first could be probably workarounded, especially if you
already have "two buffers"

> distorting the very events being measured.
> Additionally, the information will not distract from lockups
> when users view the log.
> A two-buffer system is used to ensure that the trace information
> can always be recorded without contention.

This implies that kernel bug reports will often not contain the
back trace, right? Seems like a bad thing to me because it will
make bug reports worse.


ak@xxxxxxxxxxxxxxx -- Speaking for myself only
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