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MFp4:

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Enqueue thread in LIFO, this can cause starvation, but it gives better
performance. Use _thr_queuefifo to control the frequency of FIFO vs LIFO,
you can use environment string LIBPTHREAD_QUEUE_FIFO to configure the
variable.
This commit is contained in:
David Xu 2012-05-03 09:17:31 +00:00
parent bdf942c3f0
commit 84ac0fb8ca
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=234947
3 changed files with 10 additions and 1 deletions
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4
lib/libthr/thread/thr_init.c
View File

@ -112,6 +112,7 @@ size_t _thr_stack_initial = THR_STACK_INITIAL;
int _thr_page_size;
int _thr_spinloops;
int _thr_yieldloops;
int _thr_queuefifo = 4;
int _gc_count;
struct umutex _mutex_static_lock = DEFAULT_UMUTEX;
struct umutex _cond_static_lock = DEFAULT_UMUTEX;
@ -470,6 +471,9 @@ init_private(void)
env = getenv("LIBPTHREAD_YIELDLOOPS");
if (env)
_thr_yieldloops = atoi(env);
env = getenv("LIBPTHREAD_QUEUE_FIFO");
if (env)
_thr_queuefifo = atoi(env);
TAILQ_INIT(&_thr_atfork_list);
}
init_once = 1;

1
lib/libthr/thread/thr_private.h
View File

@ -710,6 +710,7 @@ extern size_t _thr_stack_initial __hidden;
extern int _thr_page_size __hidden;
extern int _thr_spinloops __hidden;
extern int _thr_yieldloops __hidden;
extern int _thr_queuefifo __hidden;
/* Garbage thread count. */
extern int _gc_count __hidden;

6
lib/libthr/thread/thr_sleepq.c
View File

@ -39,6 +39,7 @@
struct sleepqueue_chain {
struct umutex sc_lock;
int sc_enqcnt;
LIST_HEAD(, sleepqueue) sc_queues;
int sc_type;
};
@ -124,7 +125,10 @@ _sleepq_add(void *wchan, struct pthread *td)
}
td->sleepqueue = NULL;
td->wchan = wchan;
TAILQ_INSERT_TAIL(&sq->sq_blocked, td, wle);
if (((++sc->sc_enqcnt << _thr_queuefifo) & 0xff) != 0)
TAILQ_INSERT_HEAD(&sq->sq_blocked, td, wle);
else
TAILQ_INSERT_TAIL(&sq->sq_blocked, td, wle);
}
int