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From: Tim Chen <tim.c.chen@linux.intel.com>
To: Hillf Danton <hdanton@sina.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ricardo Neri <ricardo.neri@intel.com>,
	Mel Gorman <mgorman@suse.de>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/6] sched/fair: Consider the idle state of the whole core for load balance
Date: Fri, 05 May 2023 15:49:08 -0700	[thread overview]
Message-ID: <fb54d3f550883ec7eb92a41261dabcc196634e33.camel@linux.intel.com> (raw)
In-Reply-To: <20230505071735.4083-1-hdanton@sina.com>

On Fri, 2023-05-05 at 15:17 +0800, Hillf Danton wrote:
> On 4 May 2023 09:09:55 -0700 Tim Chen <tim.c.chen@linux.intel.com>
> > From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
> > 
> > should_we_balance() traverses the group_balance_mask (AND'ed with lb_env::
> > cpus) starting from lower numbered CPUs looking for the first idle CPU.
> > 
> > In hybrid x86 systems, the siblings of SMT cores get CPU numbers, before
> > non-SMT cores:
> > 
> > 	[0, 1] [2, 3] [4, 5] 5 6 7 8
> >        b  i   b  i   b  i  b i i i
> > 
> > In the figure above, CPUs in brackets are siblings of an SMT core. The
> > rest are non-SMT cores. 'b' indicates a busy CPU, 'i' indicates an
> > idle CPU.
> 
> Better if l2-cache affinity is added in the diagram above. And better
> again if the diagram is available upon introducing hybrid x86 in the
> cover letter.

Good suggestion.  Will update the diagram and add it to cover letter.

Tim

      parent reply	other threads:[~2023-05-05 22:49 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-04 16:09 [PATCH 0/6] Enable Cluster Scheduling for x86 Hybrid CPUs Tim Chen
2023-05-04 16:09 ` [PATCH 1/6] sched/topology: Propagate SMT flags when removing degenerate domain Tim Chen
2023-05-04 16:09 ` [PATCH 2/6] sched/fair: Check whether active load balance is needed in busiest group Tim Chen
2023-05-05 12:16   ` Peter Zijlstra
2023-05-05 22:29     ` Tim Chen
2023-05-05 23:44       ` Peter Zijlstra
2023-05-09 13:31   ` Vincent Guittot
2023-05-04 16:09 ` [PATCH 3/6] sched/fair: Fix busiest group selection for asym groups Tim Chen
2023-05-05 13:19   ` Peter Zijlstra
2023-05-05 22:36     ` Tim Chen
2023-05-04 16:09 ` [PATCH 4/6] sched/fair: Skip prefer sibling move between SMT group and non-SMT group Tim Chen
2023-05-05 13:22   ` Peter Zijlstra
2023-05-05 23:07     ` Tim Chen
2023-05-05 23:38       ` Peter Zijlstra
2023-05-06  0:08         ` Peter Zijlstra
2023-05-09 13:36   ` Vincent Guittot
2023-05-09 23:35     ` Tim Chen
2023-05-04 16:09 ` [PATCH 5/6] sched/fair: Consider the idle state of the whole core for load balance Tim Chen
2023-05-05 13:23   ` Peter Zijlstra
2023-05-05 22:51     ` Tim Chen
2023-05-04 16:09 ` [PATCH 6/6] sched/x86: Add cluster topology to hybrid CPU Tim Chen
     [not found] ` <20230505071735.4083-1-hdanton@sina.com>
2023-05-05 22:49   ` Tim Chen [this message]

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