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Mon, 17 Mar 2025 18:23:22 +0000 Message-ID: <0d5200bb-5070-4225-8166-20b8b63af33d@intel.com> Date: Tue, 18 Mar 2025 02:23:10 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 0/8] sched/fair: Propagate load balancing stats up the sched domain hierarchy To: Peter Zijlstra CC: Ingo Molnar , Juri Lelli , Vincent Guittot , , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , David Vernet , "Gautham R. 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Reusing stats for newidle load >> balancing specifically ran into issues elaborated below. > > Right, it makes sense for busy load balance, newidle I think: > >> David had proposed SHARED_RUNQ [4] to improve on the shortcomings of >> newidle balance for Meta's production workloads. > > we need to look at this again. Something around the EEVDF merge made the > thing unhappy -- if we figure out what and fix it, I think this makes Could you give some links on what the issue is? The newly-idle balance fail to pull tasks after switching to EEVDF?(I don't see the connection between EEVDF and newly-idle balance on top of my head) > more sense than trying to optimize the current scheme for newidle. > > newidle really is about getting *any* work fast, which is a totally > different game than the regular busy balancing. > The newly idle iterates every CPU in the domain to find the busiest one, would the following work: find a relative busy CPU and stop the search, say, rq->nr_running >= 2 and also consider the candidate task's average duration. thanks, Chenyu