Re: [PATCH 6/6] sched: disabled rt-bandwidth by default

Ingo Molnar
2008-08-28T13:07:43Z

* Nick Piggin <nickpiggin@yahoo.com.au> wrote:

> There is no customer issue and there is no handwaving about
> compliance;

well, the reason i'm asking is that i cannot for anything in the world
imagine you being so upset about _anything_ but something that involves
benchmark runs ;-)

And what does SCHED_FIFO RT policy scheduling have to do with
performance and benchmarks? Nothing usually in the real world, except
for this little known fact: a common 'tuning' for TPC database
benchmarks is to run all DB threads as SCHED_FIFO to squeeze the last
0.1% of performance out of the setup.

So - and i'm taking an educated guess here - is SCHED_FIFO+TPC
performance perhaps one of the factors that played a role in you
initiating this thread? If yes then it's obviously an incredibly broken
use of SCHED_FIFO and we can add the sysctl tuning to the long list of
dozens of other tunings that happen before a TPC run anyway.

Hm?

Ingo