From: Peter Zijlstra <peterz@infradead.org>
To: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.comi>, Mel Gorman <mgorman@suse.de>,
Len Brown <len.brown@intel.com>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Aubrey Li <aubrey.li@linux.intel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Ricardo Neri <ricardo.neri@intel.com>,
Quentin Perret <qperret@google.com>,
"Joel Fernandes (Google)" <joel@joelfernandes.org>,
linux-kernel@vger.kernel.org, Aubrey Li <aubrey.li@intel.com>,
Ben Segall <bsegall@google.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>
Subject: Re: [PATCH 3/4] sched/fair: Consider SMT in ASYM_PACKING load balance
Date: Tue, 6 Apr 2021 13:17:28 +0200 [thread overview]
Message-ID: <YGxDSMorjMADJGIT@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20210406041108.7416-4-ricardo.neri-calderon@linux.intel.com>
On Mon, Apr 05, 2021 at 09:11:07PM -0700, Ricardo Neri wrote:
> @@ -8507,6 +8619,10 @@ static bool update_sd_pick_busiest(struct lb_env *env,
> if (!sgs->sum_h_nr_running)
> return false;
>
> + if (sgs->group_type == group_asym_packing &&
> + !asym_can_pull_tasks(env->dst_cpu, sds, sgs, sg))
> + return false;
All of this makes my head hurt; but afaict this isn't right.
Your update_sg_lb_stats() change makes that we unconditionally set
sgs->group_asym_packing, and then this is to undo that. But it's not
clear this covers all cases right.
Even if !sched_asym_prefer(), we could end up selecting this sg as
busiest, but you're just bailing out here.
next prev parent reply other threads:[~2021-04-06 13:08 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-06 4:11 [PATCH 0/4] sched/fair: Fix load balancing of SMT siblings with ASYM_PACKING Ricardo Neri
2021-04-06 4:11 ` [PATCH 1/4] sched/fair: Optimize checking for group_asym_packing Ricardo Neri
2021-04-06 4:11 ` [PATCH 2/4] sched/fair: Introduce arch_sched_asym_prefer_early() Ricardo Neri
2021-04-06 14:31 ` Vincent Guittot
2021-04-06 23:36 ` Ricardo Neri
2021-04-06 4:11 ` [PATCH 3/4] sched/fair: Consider SMT in ASYM_PACKING load balance Ricardo Neri
2021-04-06 11:17 ` Peter Zijlstra [this message]
2021-04-06 23:17 ` Ricardo Neri
2021-04-08 11:10 ` Peter Zijlstra
2021-04-09 5:12 ` Ricardo Neri
2021-04-06 11:18 ` Peter Zijlstra
2021-04-06 23:17 ` Ricardo Neri
2021-04-08 11:21 ` Peter Zijlstra
2021-04-09 5:13 ` Ricardo Neri
2021-04-06 4:11 ` [PATCH 4/4] x86/sched: Enable checks of the state of SMT siblings in load balancing Ricardo Neri
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