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Use subr_unit to allocate thread ID's with.

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Tested by:	davidxu
This commit is contained in:
Poul-Henning Kamp 2005-03-18 12:34:14 +00:00
parent be1bf4d2b8
commit 1ea7a6f806
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=143802
1 changed files with 6 additions and 78 deletions
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84
sys/kern/kern_thread.c
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@ -103,31 +103,8 @@ SYSCTL_PROC(_kern_threads, OID_AUTO, virtual_cpu, CTLTYPE_INT|CTLFLAG_RW,
0, sizeof(virtual_cpu), sysctl_kse_virtual_cpu, "I",
"debug virtual cpus");
/*
* Thread ID allocator. The allocator keeps track of assigned IDs by
* using a bitmap. The bitmap is created in parts. The parts are linked
* together.
*/
typedef u_long tid_bitmap_word;
#define TID_IDS_PER_PART 1024
#define TID_IDS_PER_IDX (sizeof(tid_bitmap_word) << 3)
#define TID_BITMAP_SIZE (TID_IDS_PER_PART / TID_IDS_PER_IDX)
#define TID_MIN (PID_MAX + 1)
struct tid_bitmap_part {
STAILQ_ENTRY(tid_bitmap_part) bmp_next;
tid_bitmap_word bmp_bitmap[TID_BITMAP_SIZE];
lwpid_t bmp_base;
int bmp_free;
};
static STAILQ_HEAD(, tid_bitmap_part) tid_bitmap =
STAILQ_HEAD_INITIALIZER(tid_bitmap);
static uma_zone_t tid_zone;
struct mtx tid_lock;
MTX_SYSINIT(tid_lock, &tid_lock, "TID lock", MTX_DEF);
static struct unrhdr *tid_unrhdr;
/*
* Prepare a thread for use.
@ -197,45 +174,10 @@ static int
thread_init(void *mem, int size, int flags)
{
struct thread *td;
struct tid_bitmap_part *bmp, *new;
int bit, idx;
td = (struct thread *)mem;
mtx_lock(&tid_lock);
STAILQ_FOREACH(bmp, &tid_bitmap, bmp_next) {
if (bmp->bmp_free)
break;
}
/* Create a new bitmap if we run out of free bits. */
if (bmp == NULL) {
mtx_unlock(&tid_lock);
new = uma_zalloc(tid_zone, M_WAITOK);
mtx_lock(&tid_lock);
bmp = STAILQ_LAST(&tid_bitmap, tid_bitmap_part, bmp_next);
if (bmp == NULL || bmp->bmp_free < TID_IDS_PER_PART/2) {
/* 1=free, 0=assigned. This way we can use ffsl(). */
memset(new->bmp_bitmap, ~0U, sizeof(new->bmp_bitmap));
new->bmp_base = (bmp == NULL) ? TID_MIN :
bmp->bmp_base + TID_IDS_PER_PART;
new->bmp_free = TID_IDS_PER_PART;
STAILQ_INSERT_TAIL(&tid_bitmap, new, bmp_next);
bmp = new;
new = NULL;
}
} else
new = NULL;
/* We have a bitmap with available IDs. */
idx = 0;
while (idx < TID_BITMAP_SIZE && bmp->bmp_bitmap[idx] == 0UL)
idx++;
bit = ffsl(bmp->bmp_bitmap[idx]) - 1;
td->td_tid = bmp->bmp_base + idx * TID_IDS_PER_IDX + bit;
bmp->bmp_bitmap[idx] &= ~(1UL << bit);
bmp->bmp_free--;
mtx_unlock(&tid_lock);
if (new != NULL)
uma_zfree(tid_zone, new);
td->td_tid = alloc_unr(tid_unrhdr);
vm_thread_new(td, 0);
cpu_thread_setup(td);
@ -254,9 +196,6 @@ static void
thread_fini(void *mem, int size)
{
struct thread *td;
struct tid_bitmap_part *bmp;
lwpid_t tid;
int bit, idx;
td = (struct thread *)mem;
turnstile_free(td->td_turnstile);
@ -264,19 +203,7 @@ thread_fini(void *mem, int size)
umtxq_free(td->td_umtxq);
vm_thread_dispose(td);
STAILQ_FOREACH(bmp, &tid_bitmap, bmp_next) {
if (td->td_tid >= bmp->bmp_base &&
td->td_tid < bmp->bmp_base + TID_IDS_PER_PART)
break;
}
KASSERT(bmp != NULL, ("No TID bitmap?"));
mtx_lock(&tid_lock);
tid = td->td_tid - bmp->bmp_base;
idx = tid / TID_IDS_PER_IDX;
bit = 1UL << (tid % TID_IDS_PER_IDX);
bmp->bmp_bitmap[idx] |= bit;
bmp->bmp_free++;
mtx_unlock(&tid_lock);
free_unr(tid_unrhdr, td->td_tid);
}
/*
@ -362,11 +289,12 @@ void
threadinit(void)
{
mtx_init(&tid_lock, "TID lock", NULL, MTX_DEF);
tid_unrhdr = new_unrhdr(PID_MAX + 1, INT_MAX, &tid_lock);
thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(),
thread_ctor, thread_dtor, thread_init, thread_fini,
UMA_ALIGN_CACHE, 0);
tid_zone = uma_zcreate("TID", sizeof(struct tid_bitmap_part),
NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
ksegrp_zone = uma_zcreate("KSEGRP", sched_sizeof_ksegrp(),
ksegrp_ctor, NULL, NULL, NULL,
UMA_ALIGN_CACHE, 0);