Date:   Thu, 9 Feb 2023 16:43:33 -0800
From:   Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Vincent Guittot <vincent.guittot@linaro.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        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>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Valentin Schneider <vschneid@redhat.com>,
        Ionela Voinescu <ionela.voinescu@arm.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, "Tim C . Chen" <tim.c.chen@intel.com>
Subject: Re: [PATCH v3 04/10] sched/fair: Let low-priority cores help
 high-priority busy SMT cores
Message-ID: <20230210004333.GA6166@ranerica-svr.sc.intel.com>
References: <20230207045838.11243-1-ricardo.neri-calderon@linux.intel.com>
 <20230207045838.11243-5-ricardo.neri-calderon@linux.intel.com>
 <CAKfTPtB_YR8e6fcx3Un0vTeJR4EJS9sOXG=wLb8rZeM5Ub4yyA@mail.gmail.com>
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On Thu, Feb 09, 2023 at 12:53:41PM +0100, Peter Zijlstra wrote:
> On Wed, Feb 08, 2023 at 08:56:32AM +0100, Vincent Guittot wrote:
> 
> > > +                       if (env->sd->flags & SD_SHARE_CPUCAPACITY ||
> > > +                           (!(env->sd->flags & SD_SHARE_CPUCAPACITY) && is_core_idle(i)))
> > 
> > This 2nd if could be merged with the upper one
> 
> Wasn't this exact same condition used in the previous patch as well?
> Does it wants to be a helper perhaps?

Patch 3 focuses on the destination CPU: make sure that it and its SMT
siblings are idle before attempting to do asym_packing balance.

This patch focuses on the busiest group: if the busiest group is an SMT
core with more than one busy sibling, help it even if it has higher
priority.