From: "Luck, Tony" <tony.luck@intel.com>
To: James Morse <james.morse@arm.com>,
"Yu, Fenghua" <fenghua.yu@intel.com>,
"Chatre, Reinette" <reinette.chatre@intel.com>,
Peter Newman <peternewman@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>,
"x86@kernel.org" <x86@kernel.org>
Cc: Shaopeng Tan <tan.shaopeng@fujitsu.com>,
Jamie Iles <quic_jiles@quicinc.com>,
Babu Moger <babu.moger@amd.com>,
Randy Dunlap <rdunlap@infradead.org>,
Drew Fustini <dfustini@baylibre.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
"patches@lists.linux.dev" <patches@lists.linux.dev>
Subject: RE: [PATCH v4 1/2] x86/resctrl: Pass domain to target CPU
Date: Fri, 8 Mar 2024 18:50:42 +0000 [thread overview]
Message-ID: <SJ1PR11MB60837F47723BE9B41B1F05E8FC272@SJ1PR11MB6083.namprd11.prod.outlook.com> (raw)
In-Reply-To: <26f23ba4-4ca5-41f6-b920-08515f494ae5@arm.com>
> > + hw_dom->ctrl_val[idx] = cfg->new_ctrl;
> > + cpu = cpumask_any(&d->cpu_mask);
>
> If this CPU is part of the domain, then cpumask_any() could chose a different CPU leading
> to an IPI, where this CPU could have done the work itself.
> smp_call_function_any() has the logic to try and run on this CPU if possible.
>
> As d->cpu_mask is still valid when you call smp_call_function_single(), could we use
> smp_call_function_any() instead?
I'd thought that cpumask_any() was smarter. But I see that it dumbly just picks the first
CPU in the mask. Great suggestion, will add to next version.
>> - cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
>> + cpu = cpumask_any(&d->cpu_mask);
>
> Same comment about picking an unlucky CPU here, smp_call_function_any() can improve our
> chances.
Will fix here too.
> Still:
> Reviewed-by: James Morse <james.morse@arm.com>
Thanks!
-Tony
next prev parent reply other threads:[~2024-03-08 18:50 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-28 19:36 Cover-cover letter for two resctrl patch sets Tony Luck
2024-02-28 19:36 ` [PATCH v4 0/2] x86/resctrl: Pass domain to target CPU Tony Luck
2024-02-28 19:36 ` [PATCH v4 1/2] " Tony Luck
2024-03-04 23:07 ` Reinette Chatre
2024-03-05 0:17 ` Luck, Tony
2024-03-05 1:31 ` Reinette Chatre
2024-03-05 16:37 ` Luck, Tony
2024-03-05 16:48 ` Reinette Chatre
2024-03-08 18:26 ` James Morse
2024-03-08 18:50 ` Luck, Tony [this message]
2024-02-28 19:36 ` [PATCH v4 2/2] x86/resctrl: Simplify call convention for MSR update functions Tony Luck
2024-03-04 23:07 ` Reinette Chatre
2024-02-28 19:36 ` [PATCH v15 0/8] Add support for Sub-NUMA cluster (SNC) systems Tony Luck
2024-02-28 19:36 ` [PATCH v15 1/8] x86/resctrl: Prepare for new domain scope Tony Luck
2024-02-28 19:36 ` [PATCH v15 2/8] x86/resctrl: Prepare to split rdt_domain structure Tony Luck
2024-02-28 19:36 ` [PATCH v15 3/8] x86/resctrl: Prepare for different scope for control/monitor operations Tony Luck
2024-02-28 19:36 ` [PATCH v15 4/8] x86/resctrl: Split the rdt_domain and rdt_hw_domain structures Tony Luck
2024-02-28 19:37 ` [PATCH v15 5/8] x86/resctrl: Add node-scope to the options for feature scope Tony Luck
2024-02-28 19:37 ` [PATCH v15 6/8] x86/resctrl: Introduce snc_nodes_per_l3_cache Tony Luck
2024-02-28 19:37 ` [PATCH v15 7/8] x86/resctrl: Sub NUMA Cluster detection and enable Tony Luck
2024-02-28 19:37 ` [PATCH v15 8/8] x86/resctrl: Update documentation with Sub-NUMA cluster changes Tony Luck
2024-03-04 23:07 ` Cover-cover letter for two resctrl patch sets Reinette Chatre
2024-03-05 22:02 ` Konstantin Ryabitsev
2024-03-05 22:27 ` Luck, Tony
2024-03-06 3:11 ` Konstantin Ryabitsev
2024-03-05 7:28 ` Maciej Wieczor-Retman
2024-03-05 17:51 ` Luck, Tony
2024-03-06 7:22 ` Maciej Wieczor-Retman
2024-03-06 7:28 ` Maciej Wieczor-Retman
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