Messages in this thread | | | Subject | Re: [RFC] Perfomance varies according to sysctl_sched_migration_cost | From | Yicong Yang <> | Date | Tue, 14 Sep 2021 20:35:28 +0800 |
| |
On 2021/9/14 19:30, Peter Zijlstra wrote: > On Tue, Sep 14, 2021 at 03:27:09PM +0800, Yicong Yang wrote: >> 2. The ABI now has been removed from sysctl and moved to debugfs. As tuning this can improve the performance >> of some workloads on some platforms, maybe it's better to make it a formal sysctl again with docs? > > It never was an ABI, there is nothing to restore. It has always been > CONFIG_SCHED_DEBUG. >
It's right that CONIG_SCHED_DEBUG is on for most releases and it's same to tune it through debugfs. So I'm not with a strong heart to restore it but just curious about this magic value since it does have some influence when tuning this on my platform.
> I'm open to topology based improvements to the code, but I don't think > user tunables are a good way. >
sure, it's better to make the scheduler topology adapted rather than manually tuned, but certainly it's not that easy to achieve. Maybe I can investigate the whole story first, seems we didn't use a constant migration_cost_ns at very beginning, to see if there's any inspiration.
Thanks.
> . >
| |