1a8cfbc450
dereference curthread. It is called only from critical_{enter,exit}(),
which already dereferences curthread. This doesn't seem to affect SMP
performance in my benchmarks, but improves MySQL transaction throughput
by about 1% on UP on my Xeon.
Head nodding: jhb, bmilekic
95 lines
3.2 KiB
C
95 lines
3.2 KiB
C
/*-
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* Copyright (c) 2002 Matthew Dillon. All Rights Reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* This file contains prototypes and high-level inlines related to
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* machine-level critical function support:
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*
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* cpu_critical_enter() - inlined
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* cpu_critical_exit() - inlined
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* cpu_critical_fork_exit() - prototyped
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* related support functions residing
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* in <arch>/<arch>/critical.c - prototyped
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*
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* $FreeBSD$
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*/
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#ifndef _MACHINE_CRITICAL_H_
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#define _MACHINE_CRITICAL_H_
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__BEGIN_DECLS
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/*
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* Prototypes - see <arch>/<arch>/critical.c
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*/
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void cpu_critical_fork_exit(void);
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#if defined(__GNUC__) || defined(__INTEL_COMPILER)
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/*
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* cpu_critical_enter:
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*
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* This routine is called from critical_enter() on the 0->1 transition
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* of td_critnest, prior to it being incremented to 1.
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*
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* If new-style critical section handling we do not have to do anything.
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* However, as a side effect any interrupts occuring while td_critnest
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* is non-zero will be deferred.
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*/
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static __inline void
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cpu_critical_enter(struct thread *td)
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{
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td->td_md.md_savecrit = intr_disable();
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}
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/*
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* cpu_critical_exit:
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*
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* This routine is called from critical_exit() on a 1->0 transition
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* of td_critnest, after it has been decremented to 0. We are
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* exiting the last critical section.
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*
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* Note that the td->critnest (1->0) transition interrupt race against
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* our int_pending/unpend() check below is handled by the interrupt
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* code for us, so we do not have to do anything fancy.
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*/
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static __inline void
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cpu_critical_exit(struct thread *td)
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{
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intr_restore(td->td_md.md_savecrit);
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}
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#else /* !(__GNUC__ || __INTEL_COMPILER) */
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void cpu_critical_enter(struct thread *td);
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void cpu_critical_exit(struct thread *td);
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#endif /* __GNUC__ || __INTEL_COMPILER */
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__END_DECLS
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#endif /* !_MACHINE_CRITICAL_H_ */
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