d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Enable ADAPTIVE_MUTEXES by default by changing the sense of the option to

Browse Source 
NO_ADAPTIVE_MUTEXES.  This option has been enabled by default on amd64 for
quite some time, and has been extensively tested on i386 and sparc64.  It
shows measurable performance gains in many circumstances, and few negative
effects.  It would be nice in t he future if adaptive mutexes actually went
to sleep after a certain amount of spinning, but that will require quite a
bit more testing.
This commit is contained in:
Scott Long 2004-07-18 15:59:03 +00:00
parent 7a76c247bd
commit 701f140800
4 changed files with 7 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sys/amd64/conf/GENERIC
View File

@ -28,7 +28,6 @@ ident GENERIC
makeoptions DEBUG=-g # Build kernel with gdb(1) debug symbols
options SCHED_ULE # ULE scheduler
options ADAPTIVE_MUTEXES # mutexes first spin lock, then sleep
options INET # InterNETworking
options INET6 # IPv6 communications protocols
options FFS # Berkeley Fast Filesystem

5
sys/conf/NOTES
View File

@ -169,8 +169,9 @@ options SMP # Symmetric MultiProcessor Kernel
# ADAPTIVE_MUTEXES changes the behavior of blocking mutexes to spin
# if the thread that currently owns the mutex is executing on another
# CPU.
options ADAPTIVE_MUTEXES
# CPU. This behaviour is enabled by default, so this option can be used
# to disable it.
options NO_ADAPTIVE_MUTEXES
# MUTEX_NOINLINE forces mutex operations to call functions to perform each
# operation rather than inlining the simple cases. This can be used to

2
sys/conf/options
View File

@ -56,7 +56,7 @@ KDB_TRACE opt_kdb.h
KDB_UNATTENDED opt_kdb.h
# Miscellaneous options.
ADAPTIVE_MUTEXES
NO_ADAPTIVE_MUTEXES
ALQ
CODA_COMPAT_5 opt_coda.h
COMPAT_43 opt_compat.h

6
sys/kern/kern_mutex.c
View File

@ -421,7 +421,7 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
{
struct turnstile *ts;
struct thread *td = curthread;
#if defined(SMP) && defined(ADAPTIVE_MUTEXES)
#if defined(SMP) && !defined(NO_ADAPTIVE_MUTEXES)
struct thread *owner;
#endif
uintptr_t v;
@ -503,7 +503,7 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
continue;
}
#if defined(SMP) && defined(ADAPTIVE_MUTEXES)
#if defined(SMP) && !defined(NO_ADAPTIVE_MUTEXES)
/*
* If the current owner of the lock is executing on another
* CPU, spin instead of blocking.
@ -518,7 +518,7 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
}
continue;
}
#endif /* SMP && ADAPTIVE_MUTEXES */
#endif /* SMP && !NO_ADAPTIVE_MUTEXES */
/*
* We definitely must sleep for this lock.