Re: [Patch 0/8] per-task delay accounting

[Shailabh Nagar]

Guillaume Thouvenin wrote:

> On Fri, 31 Mar 2006 01:42:28 -0500
> Shailabh Nagar <nagar@xxxxxxxxxxxxxx> wrote:
>
>  
>
> > Following Andrew's suggestion, here's my quick overview
> > of the various other accounting packages that have been
> > proposed on lse-tech with a focus on whether they can
> > utilize the netlink-based taskstats interface being proposed
> > by the delay accounting patches.
> >
> > Please note that unification of statistics *collection* is not
> > being discussed since that kind of merger can be done as these
> > patches get accepted, if at all, into the kernel. To try and
> > unify right away would hold every patch (esp. delay accounting !)
> > hostage to the problems in every other patch unnecessarily. As
> > long as the interface can be unified, the merger of the
> > collection bits can always happen without affecting user space.
> >
> > Stakeholders of each of these patches, on cc, are requested to
> > please correct any misunderstandings of what their patches do.
> >
> > Also, please comment on the observations about their patch's
> > ability to use the netlink-based taskstats interface, code for which
> > was posted at
> >   
> > http://www.uwsg.indiana.edu/hypermail/linux/kernel/0603.3/1787.html
> >
> >    
> [...]
>  
>
> > 5. Enhanced Linux System Accounting (Guillaume Thouvenine)
> >    
>                                                 ^^^^^^^^^^
>                                                 Thouvenin
>  
>
> > ----------------------------------------------------------   
> >
> > - Group tasks at a user level into "jobs" and aggregate,
> > at user level, per-task statistics collected by CSA and/or BSD
> > process accounting.
> >
> > - ELSA does not introduce any new requirement for either
> > collection or export of statistics from the kernel. It can use
> > either BSD and/or CSA's  method of using an accounting file.
> >
> > - ELSA needs notification of forks and exits which it can already
> > get through the process events connector in the kernel.
> >
> > Hence ELSA's needs are either met by the kernel today or are a
> > strict subset of  CSA (since BSD accounting is already there).
> >    
>
> The overview is very interesting and you have a very good comprehension
> of ELSA. As you said ELSA is a group tasks at a user level and
> everything is already in the kernel so your patches don't generate
> troubles to ELSA. As you said in the delay accounting documentation,
> delay statistics can also be collected for all tasks and a tool like
> ELSA can aggregate results for groups of processes.
>
>
> Chears,
> Guillaume
>  
Thanks Guillaume. Thats one "sign-off" on the taskstats interface then :-)

--Shailabh


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