Re: [PATCH 3/3] check: add --print-start-done to enhance watchdogs

[Dave Chinner <david@fromorbit.com>]

On Fri, Feb 16, 2024 at 10:18:59AM -0800, Luis Chamberlain wrote:
> fstests specific watchdogs want to know when the full test suite will
> start and end. Right now the kernel ring buffer can get augmented but we
> can't know for sure if it was due to a test or some odd hardware issue
> after fstests ran. This is specially true for systems left running tests in
> loops in automation where we are not running things ourselves but rather just
> get access to kernel logs, or for filesystem runner watdogs such as the one
> in kdevops [0]. It is also often not easy to determine for sure based on
> just logs when fstests check really has completed unless we have a
> matching log of who spawned that test runner. Although we could keep track of
> this ourselves by an annotation locally on the test runner, it is useful to
> have independent tools which are not attached to the process which spawned
> check to just peak into a system and verify the system's progress with
> fstests by just using the kernel log. Keeping this in the test target kernel
> ring buffer enables these use cases.
> 
> This is useful for example for filesyste checker specific watchdogs like the
> one in kdevops so that the watchdog knows when to start hunting for crashes
> based just on the kernel ring buffer, and so it also knows when the show is
> over.

Why can't the runner that requires timing information in the
kernel log just emit a message to the kernel log before it
runs check and again immediately after completion of the check
script?

-Dave.
-- 
Dave Chinner
david@fromorbit.com