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Just make the turnstile locks statics and avoid the indirect reference

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since COHERENCY_UNIT does the right thing in !MP.
This commit is contained in:
ad 2019-12-16 19:22:15 +00:00
parent 0d77a8f35e
commit c6c5943eb0
1 changed files with 13 additions and 10 deletions
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23
sys/kern/kern_turnstile.c
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@ -1,4 +1,4 @@
/* $NetBSD: kern_turnstile.c,v 1.34 2019/11/24 13:14:23 ad Exp $ */
/* $NetBSD: kern_turnstile.c,v 1.35 2019/12/16 19:22:15 ad Exp $ */
/*-
* Copyright (c) 2002, 2006, 2007, 2009, 2019 The NetBSD Foundation, Inc.
@ -60,7 +60,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_turnstile.c,v 1.34 2019/11/24 13:14:23 ad Exp $");
__KERNEL_RCSID(0, "$NetBSD: kern_turnstile.c,v 1.35 2019/12/16 19:22:15 ad Exp $");
#include <sys/param.h>
#include <sys/lockdebug.h>
@ -78,12 +78,15 @@ __KERNEL_RCSID(0, "$NetBSD: kern_turnstile.c,v 1.34 2019/11/24 13:14:23 ad Exp $
#define TS_HASH_MASK (TS_HASH_SIZE - 1)
#define TS_HASH(obj) (((uintptr_t)(obj) >> 6) & TS_HASH_MASK)
/* Keep the chains and mutex pointers apart to prevent false sharing. */
static tschain_t turnstile_chains[TS_HASH_SIZE] __cacheline_aligned;
static kmutex_t *turnstile_locks[TS_HASH_SIZE] __read_mostly;
pool_cache_t turnstile_cache __read_mostly;
extern turnstile_t turnstile0;
static union {
kmutex_t lock;
uint8_t pad[COHERENCY_UNIT];
} turnstile_locks[TS_HASH_SIZE] __cacheline_aligned;
static int turnstile_ctor(void *, void *, int);
/*
@ -98,7 +101,7 @@ turnstile_init(void)
for (i = 0; i < TS_HASH_SIZE; i++) {
LIST_INIT(&turnstile_chains[i]);
turnstile_locks[i] = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SCHED);
mutex_init(&turnstile_locks[i].lock, MUTEX_DEFAULT, IPL_SCHED);
}
turnstile_cache = pool_cache_init(sizeof(turnstile_t), coherency_unit,
@ -173,7 +176,7 @@ turnstile_lookup(wchan_t obj)
hash = TS_HASH(obj);
tc = &turnstile_chains[hash];
mutex_spin_enter(turnstile_locks[hash]);
mutex_spin_enter(&turnstile_locks[hash].lock);
LIST_FOREACH(ts, tc, ts_chain)
if (ts->ts_obj == obj)
@ -195,7 +198,7 @@ void
turnstile_exit(wchan_t obj)
{
mutex_spin_exit(turnstile_locks[TS_HASH(obj)]);
mutex_spin_exit(&turnstile_locks[TS_HASH(obj)].lock);
}
/*
@ -381,7 +384,7 @@ turnstile_block(turnstile_t *ts, int q, wchan_t obj, syncobj_t *sobj)
hash = TS_HASH(obj);
tc = &turnstile_chains[hash];
lock = turnstile_locks[hash];
lock = &turnstile_locks[hash].lock;
KASSERT(q == TS_READER_Q || q == TS_WRITER_Q);
KASSERT(mutex_owned(lock));
@ -455,7 +458,7 @@ turnstile_wakeup(turnstile_t *ts, int q, int count, lwp_t *nl)
lwp_t *l;
hash = TS_HASH(ts->ts_obj);
lock = turnstile_locks[hash];
lock = &turnstile_locks[hash].lock;
sq = &ts->ts_sleepq[q];
KASSERT(q == TS_READER_Q || q == TS_WRITER_Q);
@ -539,7 +542,7 @@ turnstile_print(volatile void *obj, void (*pr)(const char *, ...))
hash = TS_HASH(obj);
tc = &turnstile_chains[hash];
lock = turnstile_locks[hash];
lock = &turnstile_locks[hash].lock;
LIST_FOREACH(ts, tc, ts_chain)
if (ts->ts_obj == obj)