[PATCH 08/33] autonuma: define the autonuma flags

[Andrea Arcangeli <aarcange@redhat.com>]

These flags are the ones tweaked through sysfs, they control the
behavior of autonuma, from enabling disabling it, to selecting various
runtime options.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
---
 include/linux/autonuma_flags.h |  120 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 120 insertions(+), 0 deletions(-)
 create mode 100644 include/linux/autonuma_flags.h

diff --git a/include/linux/autonuma_flags.h b/include/linux/autonuma_flags.h
new file mode 100644
index 0000000..630ecc5
--- /dev/null
+++ b/include/linux/autonuma_flags.h
@@ -0,0 +1,120 @@
+#ifndef _LINUX_AUTONUMA_FLAGS_H
+#define _LINUX_AUTONUMA_FLAGS_H
+
+/*
+ * If CONFIG_AUTONUMA=n only autonuma_possible() is defined (as false)
+ * to allow optimizing away at compile time blocks of common code
+ * without using #ifdefs.
+ */
+
+#ifdef CONFIG_AUTONUMA
+
+enum autonuma_flag {
+	/*
+	 * Set if the kernel wasn't passed the "noautonuma" boot
+	 * parameter and the hardware is NUMA. If AutoNUMA is not
+	 * possible the value of all other flags becomes irrelevant
+	 * (they will never be checked) and AutoNUMA can't be enabled.
+	 *
+	 * No defaults: depends on hardware discovery and "noautonuma"
+	 * early param.
+	 */
+	AUTONUMA_POSSIBLE_FLAG,
+	/*
+	 * If AutoNUMA is possible, this defines if AutoNUMA is
+	 * currently enabled or disabled. It can be toggled at runtime
+	 * through sysfs.
+	 *
+	 * The default depends on CONFIG_AUTONUMA_DEFAULT_ENABLED.
+	 */
+	AUTONUMA_ENABLED_FLAG,
+	/*
+	 * If set through sysfs this will print lots of debug info
+	 * about the AutoNUMA activities in the kernel logs.
+	 *
+	 * Default not set.
+	 */
+	AUTONUMA_DEBUG_FLAG,
+	/*
+	 * This defines if CFS should prioritize between load
+	 * balancing fairness or NUMA affinity, if there are no idle
+	 * CPUs available. If this flag is set AutoNUMA will
+	 * prioritize on NUMA affinity and it will disregard
+	 * inter-node fairness.
+	 *
+	 * Default not set.
+	 */
+	AUTONUMA_SCHED_LOAD_BALANCE_STRICT_FLAG,
+	/*
+	 * This flag defines if the task/mm_autonuma statistics should
+	 * be inherited from the parent task/process or instead if
+	 * they should be cleared at every fork/clone. The
+	 * task/mm_autonuma statistics are always cleared across
+	 * execve and there's no way to disable that.
+	 *
+	 * Default not set.
+	 */
+	AUTONUMA_CHILD_INHERITANCE_FLAG,
+	/*
+	 * If set, this tells knuma_scand to trigger NUMA hinting page
+	 * faults at the pmd level instead of the pte level. This
+	 * reduces the number of NUMA hinting faults potentially
+	 * saving CPU time. It reduces the accuracy of the
+	 * task_autonuma statistics (but does not change the accuracy
+	 * of the mm_autonuma statistics). This flag can be toggled
+	 * through sysfs as runtime.
+	 *
+	 * This flag does not affect AutoNUMA with transparent
+	 * hugepages (THP). With THP the NUMA hinting page faults
+	 * always happen at the pmd level, regardless of the setting
+	 * of this flag. Note: there is no reduction in accuracy of
+	 * task_autonuma statistics with THP.
+	 *
+	 * Default set.
+	 */
+	AUTONUMA_SCAN_PMD_FLAG,
+};
+
+extern unsigned long autonuma_flags;
+
+static inline bool autonuma_possible(void)
+{
+	return test_bit(AUTONUMA_POSSIBLE_FLAG, &autonuma_flags);
+}
+
+static inline bool autonuma_enabled(void)
+{
+	return test_bit(AUTONUMA_ENABLED_FLAG, &autonuma_flags);
+}
+
+static inline bool autonuma_debug(void)
+{
+	return test_bit(AUTONUMA_DEBUG_FLAG, &autonuma_flags);
+}
+
+static inline bool autonuma_sched_load_balance_strict(void)
+{
+	return test_bit(AUTONUMA_SCHED_LOAD_BALANCE_STRICT_FLAG,
+			&autonuma_flags);
+}
+
+static inline bool autonuma_child_inheritance(void)
+{
+	return test_bit(AUTONUMA_CHILD_INHERITANCE_FLAG, &autonuma_flags);
+}
+
+static inline bool autonuma_scan_pmd(void)
+{
+	return test_bit(AUTONUMA_SCAN_PMD_FLAG, &autonuma_flags);
+}
+
+#else /* CONFIG_AUTONUMA */
+
+static inline bool autonuma_possible(void)
+{
+	return false;
+}
+
+#endif /* CONFIG_AUTONUMA */
+
+#endif /* _LINUX_AUTONUMA_FLAGS_H */

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