[Crash-utility] [PATCH v2 0/1] Display relative lag of each CPU

[Dave Anderson]

----- Original Message -----
> While analyzing vmcore it is useful to have an information
> about relative lag of each CPU. Usually, people do something like this:
> 
> runq -t | grep CPU | sort -k3r |
>   awk 'NR==1{now=strtonum("0x"$3)}1{printf"%s\t%7.2fs behind\n",
>        $0,(now-strtonum("0x"$3))/1000000000}'
> 
> Here, most recent runqueue timestamp is taken as a basis, and other
> runqueues are assumed to lag behind it. This information can tell
> the reviewer which CPU is experiencing some lockup, which is
> especially useful for vmcores taken in virtual machines.
> 
> I think it would be nice to have this feature implemented by crash
> utility itself.

Done -- queued for crash-7.2.1:

  https://github.com/crash-utility/crash/commit/03a3e57b9ad849314e262cac37787604a9fe8362

Thanks,
  Dave



> 
> Since this is an RFC and if this enhancement looks useful, I'd like
> to ask to assist me with output indentation since dump_on_rq_timestamp(),
> for instance, looks too implicit and (honestly) awful to use as it is.
> 
> Changes since v1:
> 
> * use calculated amount of leading spaces to indent output nicely
> 
> Oleksandr Natalenko (1):
>   runq: display relative lag of each CPU
> 
>  help.c |  4 ++-
>  task.c | 93
>  +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 95 insertions(+), 2 deletions(-)
> 
> --
> 2.15.0
> 
>