> > Volanomark runs better > > and is only 40% (instead of 80%) down from old scheduler > > without CFS.
> 40 or 80 % is still a huge regression. > Dmitry Adamushko Can anyone explain precisely what Volanomark is doing? If it's something dumb like "looping on sched_yield until the 'right' thread runs and finishes what we're waiting for" then I think any regression can be ignored. This applies if and only if CFS' sched_yield behavior is sane and Volano's is insane. A sane sched_yield implementation must do two things: 1) Reward processes that actually do yield most of their CPU time to another process. 2) Make an effort to run every ready-to-run process at the same or higher static priority level before re-scheduling this process. (That won't always be possible due to SMP issues, but a reasonable effort is needed.) If CFS is doing these two things, and Volanomark is looping on sched_yield until the 'right thread' runs, then CFS is doing the right and Volanomark isn't. Volanomark deserves to lose. If CFS binds processes to processors more tightly and thus sched_yield can't yield to a process that was planned to run on another CPU in the future, that would be a legitimate complaint about CFS. DS - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
