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-rw-r--r--include/linux/sched.h8
-rw-r--r--include/linux/sched/mm.h35
-rw-r--r--include/linux/sync_core.h21
3 files changed, 62 insertions, 2 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 166144c04ef6..92744e3f1556 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -555,6 +555,14 @@ struct task_struct {
unsigned long wakee_flip_decay_ts;
struct task_struct *last_wakee;
+ /*
+ * recent_used_cpu is initially set as the last CPU used by a task
+ * that wakes affine another task. Waker/wakee relationships can
+ * push tasks around a CPU where each wakeup moves to the next one.
+ * Tracking a recently used CPU allows a quick search for a recently
+ * used CPU that may be idle.
+ */
+ int recent_used_cpu;
int wake_cpu;
#endif
int on_rq;
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index bd422561a75e..1149533aa2fa 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -7,6 +7,7 @@
#include <linux/sched.h>
#include <linux/mm_types.h>
#include <linux/gfp.h>
+#include <linux/sync_core.h>
/*
* Routines for handling mm_structs
@@ -194,18 +195,48 @@ static inline void memalloc_noreclaim_restore(unsigned int flags)
#ifdef CONFIG_MEMBARRIER
enum {
- MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY = (1U << 0),
- MEMBARRIER_STATE_SWITCH_MM = (1U << 1),
+ MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY = (1U << 0),
+ MEMBARRIER_STATE_PRIVATE_EXPEDITED = (1U << 1),
+ MEMBARRIER_STATE_GLOBAL_EXPEDITED_READY = (1U << 2),
+ MEMBARRIER_STATE_GLOBAL_EXPEDITED = (1U << 3),
+ MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY = (1U << 4),
+ MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE = (1U << 5),
};
+enum {
+ MEMBARRIER_FLAG_SYNC_CORE = (1U << 0),
+};
+
+#ifdef CONFIG_ARCH_HAS_MEMBARRIER_CALLBACKS
+#include <asm/membarrier.h>
+#endif
+
+static inline void membarrier_mm_sync_core_before_usermode(struct mm_struct *mm)
+{
+ if (likely(!(atomic_read(&mm->membarrier_state) &
+ MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE)))
+ return;
+ sync_core_before_usermode();
+}
+
static inline void membarrier_execve(struct task_struct *t)
{
atomic_set(&t->mm->membarrier_state, 0);
}
#else
+#ifdef CONFIG_ARCH_HAS_MEMBARRIER_CALLBACKS
+static inline void membarrier_arch_switch_mm(struct mm_struct *prev,
+ struct mm_struct *next,
+ struct task_struct *tsk)
+{
+}
+#endif
static inline void membarrier_execve(struct task_struct *t)
{
}
+static inline void membarrier_mm_sync_core_before_usermode(struct mm_struct *mm)
+{
+}
#endif
#endif /* _LINUX_SCHED_MM_H */
diff --git a/include/linux/sync_core.h b/include/linux/sync_core.h
new file mode 100644
index 000000000000..013da4b8b327
--- /dev/null
+++ b/include/linux/sync_core.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SYNC_CORE_H
+#define _LINUX_SYNC_CORE_H
+
+#ifdef CONFIG_ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
+#include <asm/sync_core.h>
+#else
+/*
+ * This is a dummy sync_core_before_usermode() implementation that can be used
+ * on all architectures which return to user-space through core serializing
+ * instructions.
+ * If your architecture returns to user-space through non-core-serializing
+ * instructions, you need to write your own functions.
+ */
+static inline void sync_core_before_usermode(void)
+{
+}
+#endif
+
+#endif /* _LINUX_SYNC_CORE_H */
+