Poul-Henning Kamp 34dda7fac8 Save 16 bytes per mutex if MUTEX_PROFILING is not defined.
MUTEX_PROFILING is in opt_global.h, so this does not introduce a risk of
variant structure sizes unless foreign kernel modules are used.

This saved 16 bytes per vnode and 16 bytes per vm object for a total of
4MB on a 2GB machine.

Idea from:	alc
2002-12-29 11:14:41 +00:00

56 lines
2.1 KiB
C

/*-
* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Berkeley Software Design Inc's name may not be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _SYS__MUTEX_H_
#define _SYS__MUTEX_H_
/*
* Sleep/spin mutex.
*/
struct mtx {
struct lock_object mtx_object; /* Common lock properties. */
volatile uintptr_t mtx_lock; /* Owner and flags. */
volatile u_int mtx_recurse; /* Number of recursive holds. */
TAILQ_HEAD(, thread) mtx_blocked; /* Threads blocked on us. */
LIST_ENTRY(mtx) mtx_contested; /* Next contested mtx. */
#ifdef MUTEX_PROFILING
/*
* This does not result in variant structure sizes because
* MUTEX_PROFILING is in opt_global.h
*/
u_int64_t mtx_acqtime;
const char *mtx_filename;
int mtx_lineno;
#endif
};
#endif /* !_SYS__MUTEX_H_ */