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Date:   Wed, 9 Dec 2020 14:35:41 +0530
From:   Gautham R Shenoy <ego@linux.vnet.ibm.com>
To:     Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc:     Gautham R Shenoy <ego@linux.vnet.ibm.com>,
        Anton Blanchard <anton@ozlabs.org>,
        Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Michael Neuling <mikey@neuling.org>,
        Nicholas Piggin <npiggin@gmail.com>,
        Nathan Lynch <nathanl@linux.ibm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Valentin Schneider <valentin.schneider@arm.com>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] powerpc/smp: Parse ibm,thread-groups with multiple
 properties
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On Wed, Dec 09, 2020 at 02:05:41PM +0530, Srikar Dronamraju wrote:
> * Gautham R Shenoy <ego@linux.vnet.ibm.com> [2020-12-08 22:55:40]:
> 
> > > 
> > > NIT:
> > > tglx mentions in one of his recent comments to try keep a reverse fir tree
> > > ordering of variables where possible.
> > 
> > I suppose you mean moving the longer local variable declarations to to
> > the top and shorter ones to the bottom. Thanks. Will fix this.
> > 
> 
> Yes.
> 
> > > > +	}
> > > > +
> > > > +	if (!tg)
> > > > +		return -EINVAL;
> > > > +
> > > > +	cpu_group_start = get_cpu_thread_group_start(cpu, tg);
> > > 
> > > This whole hunk should be moved to a new function and called before
> > > init_cpu_cache_map. It will simplify the logic to great extent.
> > 
> > I suppose you are referring to the part where we select the correct
> > tg. Yeah, that can move to a different helper.
> > 
> 
> Yes, I would prefer if we could call this new helper outside
> init_cpu_cache_map.
> 
> > > > 
> > > > -	zalloc_cpumask_var_node(&per_cpu(cpu_l1_cache_map, cpu),
> > > > -				GFP_KERNEL, cpu_to_node(cpu));
> > > > +	mask = &per_cpu(cpu_l1_cache_map, cpu);
> > > > +
> > > > +	zalloc_cpumask_var_node(mask, GFP_KERNEL, cpu_to_node(cpu));
> > > > 
> > > 
> > > This hunk (and the next hunk) should be moved to next patch.
> > >
> > 
> > The next patch is only about introducing  THREAD_GROUP_SHARE_L2. Hence
> > I put in any other code in this patch, since it seems to be a logical
> > place to collate whatever we have in a generic form.
> > 
> 
> While I am fine with it, having a pointer that always points to the same
> mask looks wierd.

Sure. Moving some of this to a separate preparatory patch.

> 
> -- 
> Thanks and Regards
> Srikar Dronamraju