[ust.git] / include / ust / clock.h

/* Copyright (C) 2010  Pierre-Marc Fournier
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#ifndef UST_CLOCK_H
#define UST_CLOCK_H

#include <time.h>
#include <sys/time.h>
#include <ust/kcompat/kcompat.h>

/* TRACE CLOCK */

/* There are two types of clocks that can be used.
   - TSC based clock
   - gettimeofday() clock

   Microbenchmarks on Linux 2.6.30 on Core2 Duo 3GHz (functions are inlined):
     Calls (100000000) to tsc(): 4004035641 cycles or 40 cycles/call
     Calls (100000000) to gettimeofday(): 9723158352 cycles or 97 cycles/call

   For merging traces with the kernel, a time source compatible with that of
   the kernel is necessary.

   Instead of gettimeofday(), we are now using clock_gettime for better
   precision and monotonicity.

*/

#define TRACE_CLOCK_GENERIC
#ifdef TRACE_CLOCK_GENERIC

static __inline__ u64 trace_clock_read64(void)
{
	struct timespec ts;
	u64 retval;

	clock_gettime(CLOCK_MONOTONIC, &ts);
	retval = ts.tv_sec;
	retval *= 1000000000;
	retval += ts.tv_nsec;

	return retval;
}

#else

#if __i386 || __x86_64

/* WARNING: Make sure to set frequency and scaling functions that will not
 * result in lttv timestamps (sec.nsec) with seconds greater than 2**32-1.
 */
static __inline__ u64 trace_clock_read64(void)
{
	uint32_t low;
	uint32_t high;
	uint64_t retval;
	__asm__ volatile ("rdtsc\n" : "=a" (low), "=d" (high));

	retval = high;
	retval <<= 32;
	return retval | low;
}

#endif /* __i386 || __x86_64 */

#ifdef __PPC__

static __inline__ u64 trace_clock_read64(void)
{
	unsigned long tb_l;
	unsigned long tb_h;
	unsigned long tb_h2;
	u64 tb;

	__asm__ (
		"1:\n\t"
		"mftbu %[rhigh]\n\t"
		"mftb %[rlow]\n\t"
		"mftbu %[rhigh2]\n\t"
		"cmpw %[rhigh],%[rhigh2]\n\t"
		"bne 1b\n\t"
	: [rhigh] "=r" (tb_h), [rhigh2] "=r" (tb_h2), [rlow] "=r" (tb_l));
	
	tb = tb_h;
	tb <<= 32;
	tb |= tb_l;

	return tb;
}

#endif /* __PPC__ */

#endif /* ! UST_TRACE_CLOCK_GENERIC */

static __inline__ u64 trace_clock_frequency(void)
{
	return 1000000000LL;
}

static __inline__ u32 trace_clock_freq_scale(void)
{
	return 1;
}

#endif /* UST_CLOCK_H */
Commit	Line	Data
518d7abb PMF	1	/* Copyright (C) 2010 Pierre-Marc Fournier
	2	*
	3	* This library is free software; you can redistribute it and/or
	4	* modify it under the terms of the GNU Lesser General Public
	5	* License as published by the Free Software Foundation; either
	6	* version 2.1 of the License, or (at your option) any later version.
	7	*
	8	* This library is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* Lesser General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU Lesser General Public
	14	* License along with this library; if not, write to the Free Software
	15	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	16	*/
	17
	18	#ifndef UST_CLOCK_H
	19	#define UST_CLOCK_H
	20
ca4525b5	21	#include <time.h>
518d7abb PMF	22	#include <sys/time.h>
	23	#include <ust/kcompat/kcompat.h>
	24
	25	/* TRACE CLOCK */
	26
	27	/* There are two types of clocks that can be used.
	28	- TSC based clock
	29	- gettimeofday() clock
	30
	31	Microbenchmarks on Linux 2.6.30 on Core2 Duo 3GHz (functions are inlined):
	32	Calls (100000000) to tsc(): 4004035641 cycles or 40 cycles/call
	33	Calls (100000000) to gettimeofday(): 9723158352 cycles or 97 cycles/call
	34
	35	For merging traces with the kernel, a time source compatible with that of
	36	the kernel is necessary.
	37
ca4525b5 PMF	38	Instead of gettimeofday(), we are now using clock_gettime for better
	39	precision and monotonicity.
	40
518d7abb PMF	41	*/
	42
	43	#define TRACE_CLOCK_GENERIC
	44	#ifdef TRACE_CLOCK_GENERIC
	45
	46	static __inline__ u64 trace_clock_read64(void)
	47	{
ca4525b5	48	struct timespec ts;
518d7abb PMF	49	u64 retval;
518d7abb PMF	50
ca4525b5 PMF	51	clock_gettime(CLOCK_MONOTONIC, &ts);
	52	retval = ts.tv_sec;
	53	retval *= 1000000000;
	54	retval += ts.tv_nsec;
518d7abb PMF	55
	56	return retval;
	57	}
	58
	59	#else
	60
	61	#if __i386 \|\| __x86_64
	62
	63	/* WARNING: Make sure to set frequency and scaling functions that will not
	64	* result in lttv timestamps (sec.nsec) with seconds greater than 2**32-1.
	65	*/
	66	static __inline__ u64 trace_clock_read64(void)
	67	{
	68	uint32_t low;
	69	uint32_t high;
	70	uint64_t retval;
	71	__asm__ volatile ("rdtsc\n" : "=a" (low), "=d" (high));
	72
	73	retval = high;
	74	retval <<= 32;
	75	return retval \| low;
	76	}
	77
	78	#endif /* __i386 \|\| __x86_64 */
	79
	80	#ifdef __PPC__
	81
	82	static __inline__ u64 trace_clock_read64(void)
	83	{
	84	unsigned long tb_l;
	85	unsigned long tb_h;
	86	unsigned long tb_h2;
	87	u64 tb;
	88
	89	__asm__ (
	90	"1:\n\t"
	91	"mftbu %[rhigh]\n\t"
	92	"mftb %[rlow]\n\t"
	93	"mftbu %[rhigh2]\n\t"
	94	"cmpw %[rhigh],%[rhigh2]\n\t"
	95	"bne 1b\n\t"
	96	: [rhigh] "=r" (tb_h), [rhigh2] "=r" (tb_h2), [rlow] "=r" (tb_l));
	97
	98	tb = tb_h;
	99	tb <<= 32;
	100	tb \|= tb_l;
	101
	102	return tb;
	103	}
	104
	105	#endif /* __PPC__ */
	106
	107	#endif /* ! UST_TRACE_CLOCK_GENERIC */
	108
	109	static __inline__ u64 trace_clock_frequency(void)
	110	{
ca4525b5	111	return 1000000000LL;
518d7abb PMF	112	}
	113
	114	static __inline__ u32 trace_clock_freq_scale(void)
	115	{
	116	return 1;
	117	}
	118
	119	#endif /* UST_CLOCK_H */