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-rw-r--r--kernel/include/linux/delayacct.h153
1 files changed, 153 insertions, 0 deletions
diff --git a/kernel/include/linux/delayacct.h b/kernel/include/linux/delayacct.h
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+++ b/kernel/include/linux/delayacct.h
@@ -0,0 +1,153 @@
+/* delayacct.h - per-task delay accounting
+ *
+ * Copyright (C) Shailabh Nagar, IBM Corp. 2006
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_DELAYACCT_H
+#define _LINUX_DELAYACCT_H
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+/*
+ * Per-task flags relevant to delay accounting
+ * maintained privately to avoid exhausting similar flags in sched.h:PF_*
+ * Used to set current->delays->flags
+ */
+#define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */
+#define DELAYACCT_PF_BLKIO 0x00000002 /* I am waiting on IO */
+
+#ifdef CONFIG_TASK_DELAY_ACCT
+
+extern int delayacct_on; /* Delay accounting turned on/off */
+extern struct kmem_cache *delayacct_cache;
+extern void delayacct_init(void);
+extern void __delayacct_tsk_init(struct task_struct *);
+extern void __delayacct_tsk_exit(struct task_struct *);
+extern void __delayacct_blkio_start(void);
+extern void __delayacct_blkio_end(void);
+extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
+extern __u64 __delayacct_blkio_ticks(struct task_struct *);
+extern void __delayacct_freepages_start(void);
+extern void __delayacct_freepages_end(void);
+
+static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
+{
+ if (p->delays)
+ return (p->delays->flags & DELAYACCT_PF_BLKIO);
+ else
+ return 0;
+}
+
+static inline void delayacct_set_flag(int flag)
+{
+ if (current->delays)
+ current->delays->flags |= flag;
+}
+
+static inline void delayacct_clear_flag(int flag)
+{
+ if (current->delays)
+ current->delays->flags &= ~flag;
+}
+
+static inline void delayacct_tsk_init(struct task_struct *tsk)
+{
+ /* reinitialize in case parent's non-null pointer was dup'ed*/
+ tsk->delays = NULL;
+ if (delayacct_on)
+ __delayacct_tsk_init(tsk);
+}
+
+/* Free tsk->delays. Called from bad fork and __put_task_struct
+ * where there's no risk of tsk->delays being accessed elsewhere
+ */
+static inline void delayacct_tsk_free(struct task_struct *tsk)
+{
+ if (tsk->delays)
+ kmem_cache_free(delayacct_cache, tsk->delays);
+ tsk->delays = NULL;
+}
+
+static inline void delayacct_blkio_start(void)
+{
+ delayacct_set_flag(DELAYACCT_PF_BLKIO);
+ if (current->delays)
+ __delayacct_blkio_start();
+}
+
+static inline void delayacct_blkio_end(void)
+{
+ if (current->delays)
+ __delayacct_blkio_end();
+ delayacct_clear_flag(DELAYACCT_PF_BLKIO);
+}
+
+static inline int delayacct_add_tsk(struct taskstats *d,
+ struct task_struct *tsk)
+{
+ if (!delayacct_on || !tsk->delays)
+ return 0;
+ return __delayacct_add_tsk(d, tsk);
+}
+
+static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
+{
+ if (tsk->delays)
+ return __delayacct_blkio_ticks(tsk);
+ return 0;
+}
+
+static inline void delayacct_freepages_start(void)
+{
+ if (current->delays)
+ __delayacct_freepages_start();
+}
+
+static inline void delayacct_freepages_end(void)
+{
+ if (current->delays)
+ __delayacct_freepages_end();
+}
+
+#else
+static inline void delayacct_set_flag(int flag)
+{}
+static inline void delayacct_clear_flag(int flag)
+{}
+static inline void delayacct_init(void)
+{}
+static inline void delayacct_tsk_init(struct task_struct *tsk)
+{}
+static inline void delayacct_tsk_free(struct task_struct *tsk)
+{}
+static inline void delayacct_blkio_start(void)
+{}
+static inline void delayacct_blkio_end(void)
+{}
+static inline int delayacct_add_tsk(struct taskstats *d,
+ struct task_struct *tsk)
+{ return 0; }
+static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
+{ return 0; }
+static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
+{ return 0; }
+static inline void delayacct_freepages_start(void)
+{}
+static inline void delayacct_freepages_end(void)
+{}
+
+#endif /* CONFIG_TASK_DELAY_ACCT */
+
+#endif