From: Tim Chen <tim.c.chen@linux.intel.com>
To: Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Ricardo Neri <ricardo.neri@intel.com>,
"Ravi V . Shankar" <ravi.v.shankar@intel.com>,
Ben Segall <bsegall@google.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Len Brown <len.brown@intel.com>, Mel Gorman <mgorman@suse.de>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Steven Rostedt <rostedt@goodmis.org>,
Valentin Schneider <vschneid@redhat.com>,
Ionela Voinescu <ionela.voinescu@arm.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
naveen.n.rao@linux.vnet.ibm.com,
Yicong Yang <yangyicong@hisilicon.com>,
Barry Song <v-songbaohua@oppo.com>, Chen Yu <yu.c.chen@intel.com>,
Hillf Danton <hdanton@sina.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [Patch v3 4/6] sched/fair: Consider the idle state of the whole core for load balance
Date: Fri, 14 Jul 2023 15:16:18 -0700 [thread overview]
Message-ID: <5dbc278117107bcc4047dc55f783dad397da1704.camel@linux.intel.com> (raw)
In-Reply-To: <29f8bc23-9b17-0a21-baa5-3eee1322f8f0@linux.vnet.ibm.com>
On Fri, 2023-07-14 at 18:32 +0530, Shrikanth Hegde wrote:
>
>
>
> Tried on a symmetric system with all cores having SMT=4 as well. There was reduction in migrations here as well.
> Didnt observe any major regressions when microbenchmarks run alone. Such as hackbench, stress-ng.
>
> So. Here is tested-by.
> Tested-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
Thanks for testing.
>
>
> > +
> > /* Are we the first CPU of this group ? */
> > return group_balance_cpu(sg) == env->dst_cpu;
> > }
>
> One doubt though, Here a fully idle core would be chosen instead of first idle cpu in the
> group (if there is one). Since coming out of idle of SMT is faster compared to a fully idle core,
> would latency increase? Or that concerns mainly wakeup path?
Yeah, I think that concern is for the wakeup path and not for the balance path.
Tim
next prev parent reply other threads:[~2023-07-14 22:16 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-07 22:56 [Patch v3 0/6] Enable Cluster Scheduling for x86 Hybrid CPUs Tim Chen
2023-07-07 22:57 ` [Patch v3 1/6] sched/fair: Determine active load balance for SMT sched groups Tim Chen
2023-07-14 13:06 ` Shrikanth Hegde
2023-07-14 23:05 ` Tim Chen
2023-07-15 18:25 ` Tim Chen
2023-07-16 19:36 ` Shrikanth Hegde
2023-07-17 11:10 ` Peter Zijlstra
2023-07-17 12:18 ` Shrikanth Hegde
2023-07-17 13:37 ` Peter Zijlstra
2023-07-17 14:58 ` [PATCH] sched/fair: Add SMT4 group_smt_balance handling Shrikanth Hegde
2023-07-27 3:11 ` Tim Chen
2023-07-27 13:32 ` Tim Chen
2023-08-07 9:36 ` Shrikanth Hegde
2023-08-21 19:19 ` Tim Chen
2023-09-05 8:03 ` Shrikanth Hegde
2023-09-05 9:49 ` Peter Zijlstra
2023-09-05 18:37 ` Tim Chen
2023-09-06 9:29 ` Shrikanth Hegde
2023-09-06 15:42 ` Tim Chen
2023-09-07 8:58 ` Shrikanth Hegde
2023-09-07 17:42 ` Tim Chen
2023-09-12 10:29 ` [tip: sched/urgent] sched/fair: Fix " tip-bot2 for Tim Chen
2023-09-13 13:11 ` tip-bot2 for Tim Chen
2023-09-05 10:38 ` [PATCH] sched/fair: Add " Peter Zijlstra
2023-09-05 10:41 ` Peter Zijlstra
2023-09-05 17:54 ` Tim Chen
2023-09-06 8:23 ` Peter Zijlstra
2023-09-06 15:45 ` Tim Chen
2023-07-18 6:07 ` [Patch v3 1/6] sched/fair: Determine active load balance for SMT sched groups Tobias Huschle
2023-07-18 14:52 ` Shrikanth Hegde
2023-07-19 8:14 ` Tobias Huschle
2023-07-14 14:53 ` Tobias Huschle
2023-07-14 23:29 ` Tim Chen
2023-07-07 22:57 ` [Patch v3 2/6] sched/topology: Record number of cores in sched group Tim Chen
2023-07-10 20:33 ` Valentin Schneider
2023-07-10 22:13 ` Tim Chen
2023-07-12 9:27 ` Valentin Schneider
2023-07-10 22:40 ` Tim Chen
2023-07-11 11:31 ` Peter Zijlstra
2023-07-11 16:32 ` Tim Chen
2023-07-07 22:57 ` [Patch v3 3/6] sched/fair: Implement prefer sibling imbalance calculation between asymmetric groups Tim Chen
2023-07-14 13:14 ` Shrikanth Hegde
2023-07-14 14:22 ` Tobias Huschle
2023-07-14 23:35 ` Tim Chen
2023-07-14 20:44 ` Tim Chen
2023-07-14 23:23 ` Tim Chen
2023-07-15 0:11 ` Tim Chen
2023-07-07 22:57 ` [Patch v3 4/6] sched/fair: Consider the idle state of the whole core for load balance Tim Chen
2023-07-14 13:02 ` Shrikanth Hegde
2023-07-14 22:16 ` Tim Chen [this message]
2023-07-07 22:57 ` [Patch v3 5/6] sched/x86: Add cluster topology to hybrid CPU Tim Chen
2023-07-08 12:31 ` Peter Zijlstra
2023-07-10 16:13 ` Tim Chen
2023-07-07 22:57 ` [Patch v3 6/6] sched/debug: Dump domains' sched group flags Tim Chen
2023-07-10 20:33 ` Valentin Schneider
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