From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Nathan Lynch <nathanl@linux.ibm.com>,
Oliver OHalloran <oliveroh@au1.ibm.com>,
Michael Neuling <mikey@linux.ibm.com>,
Gautham R Shenoy <ego@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
Jordan Niethe <jniethe5@gmail.com>,
Anton Blanchard <anton@au1.ibm.com>,
LKML <linux-kernel@vger.kernel.org>,
Nick Piggin <npiggin@au1.ibm.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Valentin Schneider <valentin.schneider@arm.com>
Subject: Re: [PATCH v2 01/10] powerpc/smp: Cache node for reuse
Date: Wed, 22 Jul 2020 13:34:24 +0530 [thread overview]
Message-ID: <20200722080424.GF9290@linux.vnet.ibm.com> (raw)
In-Reply-To: <87imegq9my.fsf@mpe.ellerman.id.au>
* Michael Ellerman <michaele@au1.ibm.com> [2020-07-22 17:41:41]:
> Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes:
> > While cpu_to_node is inline function with access to per_cpu variable.
> > However when using repeatedly, it may be cleaner to cache it in a local
> > variable.
>
> It's not clear what "cleaner" is supposed to mean. Are you saying it
> makes the source clearer, or the generated code?
>
> I'm not sure it will make any difference to the latter.
I meant the source code, I am okay dropping the hunks that try to cache
cpu_to_node.
>
> > Also fix a build error in a some weird config.
> > "error: _numa_cpu_lookup_table_ undeclared"
>
> Separate patch please.
Okay, will do.
>
> > No functional change
>
> The ifdef change means that's not true.
Okay
> > @@ -854,20 +854,24 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
> > cpu_callin_map[boot_cpuid] = 1;
> >
> > for_each_possible_cpu(cpu) {
> > + int node = cpu_to_node(cpu);
> > +
>
> Does cpu_to_node() even work here?
Except in the case where NUMA is not enabled, (when cpu_to_node would return
-1), It should work here since numa initialization would have happened by
now. It cpu_to_node(cpu) should work once numa_setup_cpu() /
map_cpu_to_node() gets called. And those are being called before this.
>
> Doesn't look like it to me.
>
> More fallout from 8c272261194d ("powerpc/numa: Enable USE_PERCPU_NUMA_NODE_ID") ?
>
> > }
> >
> > /* Init the cpumasks so the boot CPU is related to itself */
--
Thanks and Regards
Srikar Dronamraju
next prev parent reply other threads:[~2020-07-22 8:06 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 11:38 [PATCH v2 00/10] Coregroup support on Powerpc Srikar Dronamraju
2020-07-21 11:38 ` [PATCH v2 01/10] powerpc/smp: Cache node for reuse Srikar Dronamraju
2020-07-22 7:41 ` Michael Ellerman
2020-07-22 8:04 ` Srikar Dronamraju [this message]
2020-07-21 11:38 ` [PATCH v2 02/10] powerpc/smp: Merge Power9 topology with Power topology Srikar Dronamraju
2020-07-22 5:48 ` Gautham R Shenoy
2020-07-21 11:38 ` [PATCH v2 03/10] powerpc/smp: Move powerpc_topology above Srikar Dronamraju
2020-07-21 11:38 ` [PATCH v2 04/10] powerpc/smp: Enable small core scheduling sooner Srikar Dronamraju
2020-07-22 5:59 ` Gautham R Shenoy
2020-07-22 6:59 ` Srikar Dronamraju
2020-07-21 11:38 ` [PATCH v2 05/10] powerpc/smp: Dont assume l2-cache to be superset of sibling Srikar Dronamraju
2020-07-22 6:21 ` Gautham R Shenoy
2020-07-22 6:57 ` Srikar Dronamraju
2020-07-24 7:10 ` Gautham R Shenoy
2020-07-21 11:38 ` [PATCH v2 06/10] powerpc/smp: Generalize 2nd sched domain Srikar Dronamraju
2020-07-22 6:56 ` Gautham R Shenoy
2020-07-22 7:39 ` Srikar Dronamraju
2020-07-22 7:46 ` peterz
2020-07-22 8:18 ` Srikar Dronamraju
2020-07-22 8:48 ` Peter Zijlstra
2020-07-22 8:54 ` peterz
2020-07-21 11:38 ` [PATCH v2 07/10] Powerpc/numa: Detect support for coregroup Srikar Dronamraju
2020-07-21 11:38 ` [PATCH v2 08/10] powerpc/smp: Allocate cpumask only after searching thread group Srikar Dronamraju
2020-07-21 11:38 ` [PATCH v2 09/10] Powerpc/smp: Create coregroup domain Srikar Dronamraju
2020-07-22 7:04 ` Gautham R Shenoy
2020-07-22 7:29 ` Srikar Dronamraju
2020-07-21 11:38 ` [PATCH v2 10/10] powerpc/smp: Implement cpu_to_coregroup_id Srikar Dronamraju
2020-07-22 7:06 ` Gautham R Shenoy
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