Messages in this thread Patch in this message | | | From | Ricardo Neri <> | Subject | [PATCH v3 16/24] thermal: intel: hfi: Define a default class for unclassified tasks | Date | Mon, 6 Feb 2023 21:10:57 -0800 |
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A task may be unclassified if it has been recently created, spend most of its lifetime sleeping, or hardware has not provided a classification.
Most tasks will be eventually classified as scheduler's IPC class 1 (HFI class 0). This class corresponds to the capabilities in the legacy, classless, HFI table.
IPC class 1 is a reasonable choice until hardware provides an actual classification. Meanwhile, the scheduler will place classes of tasks with higher IPC scores on higher-performance CPUs.
Cc: Ben Segall <bsegall@google.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ionela Voinescu <ionela.voinescu@arm.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Len Brown <len.brown@intel.com> Cc: Lukasz Luba <lukasz.luba@arm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim C. Chen <tim.c.chen@intel.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: x86@kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> --- Changes since v2: * None
Changes since v1: * Now the default class is 1. --- drivers/thermal/intel/intel_hfi.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/thermal/intel/intel_hfi.c b/drivers/thermal/intel/intel_hfi.c index fa9b4a678d92..7ea6acce7107 100644 --- a/drivers/thermal/intel/intel_hfi.c +++ b/drivers/thermal/intel/intel_hfi.c @@ -185,6 +185,19 @@ static struct workqueue_struct *hfi_updates_wq; #ifdef CONFIG_IPC_CLASSES static int __percpu *hfi_ipcc_scores; +/* + * A task may be unclassified if it has been recently created, spend most of + * its lifetime sleeping, or hardware has not provided a classification. + * + * Most tasks will be classified as scheduler's IPC class 1 (HFI class 0) + * eventually. Meanwhile, the scheduler will place classes of tasks with higher + * IPC scores on higher-performance CPUs. + * + * IPC class 1 is a reasonable choice. It matches the performance capability + * of the legacy, classless, HFI table. + */ +#define HFI_UNCLASSIFIED_DEFAULT 1 + void intel_hfi_update_ipcc(struct task_struct *curr) { union hfi_thread_feedback_char_msr msr; @@ -215,7 +228,7 @@ unsigned long intel_hfi_get_ipcc_score(unsigned short ipcc, int cpu) return -EINVAL; if (ipcc == IPC_CLASS_UNCLASSIFIED) - return -EINVAL; + ipcc = HFI_UNCLASSIFIED_DEFAULT; /* * Scheduler IPC classes start at 1. HFI classes start at 0. -- 2.25.1
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