/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- *
+ *
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
- *
+ *
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
- *
+ *
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
- *
+ *
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* @OSF_COPYRIGHT@
*/
-/*
+/*
* Mach Operating System
* Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
* All Rights Reserved.
- *
+ *
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
- *
+ *
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- *
+ *
* Carnegie Mellon requests users of this software to return to
- *
+ *
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
- *
+ *
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
*/
-#ifndef _KERN_TIMER_H_
+#ifndef _KERN_TIMER_H_
#define _KERN_TIMER_H_
-#include <stat_time.h>
-
#include <kern/kern_types.h>
/*
- * Definitions for high resolution timers. A check
- * word on the high portion allows atomic updates.
+ * Some platforms have very expensive timebase routines. An optimization
+ * is to avoid switching timers on kernel exit/entry, which results in all
+ * time billed to the system timer. However, when exposed to userspace,
+ * we report as user time to indicate that work was done on behalf of
+ * userspace.
+ *
+ * Although this policy is implemented as a global variable, we snapshot it
+ * at key points in the thread structure (when the thread is locked and
+ * executing in the kernel) to avoid imbalances.
*/
-
-struct timer {
- uint32_t low_bits;
- uint32_t high_bits;
- uint32_t high_bits_check;
-#if !STAT_TIME
- uint32_t tstamp;
-#endif /* STAT_TIME */
-};
-
-typedef struct timer timer_data_t, *timer_t;
+extern int precise_user_kernel_time;
/*
- * Exported kernel interface to timers
+ * thread must be locked, or be the current executing thread, so that
+ * it doesn't transition from user to kernel while updating the
+ * thread-local value (or in kernel debugger context). In the future,
+ * we make take into account task-level or thread-level policy.
*/
+#define use_precise_user_kernel_time(thread) (precise_user_kernel_time)
-#if STAT_TIME
-
-#include <kern/macro_help.h>
-
-/* Advance a timer by the specified amount */
-#define TIMER_BUMP(timer, ticks) \
-MACRO_BEGIN \
- uint32_t old_low, low; \
- \
- old_low = (timer)->low_bits; \
- low = old_low + (ticks); \
- if (low < old_low) \
- timer_update((timer), (timer)->high_bits + 1, low); \
- else \
- (timer)->low_bits = low; \
-MACRO_END
-
-#define timer_switch(tstamp, new_timer)
-#define timer_event(tstamp, new_timer)
-
-#else /* STAT_TIME */
-
-/* Update the current timer and start a new one */
-extern void timer_switch(
- uint32_t tstamp,
- timer_t new_timer);
-
-#define TIMER_BUMP(timer, ticks)
+/*
+ * Definitions for high resolution timers.
+ */
-#endif /* STAT_TIME */
+#if __LP64__
+#define TIMER_ALIGNMENT
+#else
+#define TIMER_ALIGNMENT __attribute__((packed, aligned(4)))
+#endif
-/* Initialize a timer */
-extern void timer_init(
- timer_t timer);
+struct timer {
+ uint64_t tstamp;
+#if defined(__LP64__)
+ uint64_t all_bits;
+#else /* defined(__LP64__) */
+ /* A check word on the high portion allows atomic updates. */
+ uint32_t low_bits;
+ uint32_t high_bits;
+ uint32_t high_bits_check;
+#endif /* !defined(__LP64__) */
+} TIMER_ALIGNMENT;
+
+typedef struct timer timer_data_t, *timer_t;
-/* Update a saved timer value and return delta to current value */
-extern uint64_t timer_delta(
- timer_t timer,
- uint64_t *save);
+/*
+ * Initialize the `timer`.
+ */
+void timer_init(timer_t timer);
/*
- * Exported hardware interface to timers
+ * Start the `timer` at time `tstamp`.
*/
+void timer_start(timer_t timer, uint64_t tstamp);
-/* Read timer value */
-extern uint64_t timer_grab(
- timer_t timer);
+/*
+ * Stop the `timer` and update it with time `tstamp`.
+ */
+void timer_stop(timer_t timer, uint64_t tstamp);
-/* Update timer value */
-extern void timer_update(
- timer_t timer,
- uint32_t new_high,
- uint32_t new_low);
+/*
+ * Update the `timer` at time `tstamp`, leaving it running.
+ */
+void timer_update(timer_t timer, uint64_t tstamp);
-#if !STAT_TIME
+/*
+ * Update the `timer` with time `tstamp` and start `new_timer`.
+ */
+void timer_switch(timer_t timer, uint64_t tstamp, timer_t new_timer);
-/* Update the current timer at an event */
-extern void timer_event(
- uint32_t tstamp,
- timer_t new_timer);
+/*
+ * Update the thread timer at an "event," like a context switch, at time
+ * `tstamp`. This stops the current timer and starts the `new_timer` running.
+ *
+ * Must be called with interrupts disabled.
+ */
+void processor_timer_switch_thread(uint64_t tstamp, timer_t new_timer);
-#endif /* STAT_TIME */
+/*
+ * Return the difference between the `timer` and a previous value pointed to by
+ * `prev_in_cur_out`. Store the current value of the timer to
+ * `prev_in_cur_out`.
+ */
+uint64_t timer_delta(timer_t timer, uint64_t *prev_in_cur_out);
-#endif /* _KERN_TIMER_H_ */
+/*
+ * Read the accumulated time of `timer`.
+ */
+#if defined(__LP64__)
+static inline
+uint64_t
+timer_grab(timer_t timer)
+{
+ return timer->all_bits;
+}
+#else /* defined(__LP64__) */
+uint64_t timer_grab(timer_t timer);
+#endif /* !defined(__LP64__) */
+
+#endif /* _KERN_TIMER_H_ */
projects / apple / xnu.git / blobdiff