diff mbox series

[v2,17/22] sched/task_struct: Add helpers for IPC classification

Message ID 20221128132100.30253-18-ricardo.neri-calderon@linux.intel.com
State New
Headers
Series sched: Introduce IPC classes for load balance |

Commit Message

Ricardo Neri Nov. 28, 2022, 1:20 p.m. UTC 
  The unprocessed classification that hardware provides for a task may not
be usable by the scheduler: the classification may change too frequently or
architectures may want to consider extra factors. For instance, some
processors with Intel Thread Director need to consider the state of the SMT
siblings of a core.

Provide per-task helper variables that architectures can use to post-
process the classification that hardware provides.

Cc: Ben Segall <bsegall@google.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Len Brown <len.brown@intel.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 v1:
 * Used bit-fields to fit all the IPC class data in 4 bytes. (PeterZ)
 * Shortened names of the helpers.
 * Renamed helpers with the ipcc_ prefix.
 * Reworded commit message for clarity
---
 include/linux/sched.h | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/sched.h b/include/linux/sched.h
index ddabc7449edd..8a99aa316c37 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1532,7 +1532,17 @@  struct task_struct {
 	 * A hardware-defined classification of task based on the number
 	 * of instructions per cycle.
 	 */
-	unsigned int			ipcc;
+	unsigned int			ipcc : 9;
+	/*
+	 * A candidate classification that arch-specific implementations
+	 * qualify for correctness.
+	 */
+	unsigned int			ipcc_tmp : 9;
+	/*
+	 * Counter to filter out transient the candidate classification
+	 * of a task
+	 */
+	unsigned int			ipcc_cntr : 14;
 #endif
 
 	/*