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Change critical section protection for dummynet from splnet() to

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splimp() -- we need it because dummynet can be invoked by the
bridging code at splimp().

This should cure the pipe "stalls" that several people have been
reporting on -stable while using bridging+dummynet (the problem
would not affect routers using dummynet).
This commit is contained in:
Luigi Rizzo 2001-01-22 23:04:13 +00:00
parent d2db050252
commit 8b2cd62d7d
1 changed files with 45 additions and 15 deletions
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60
sys/netinet/ip_dummynet.c
View File

@ -33,9 +33,21 @@
/*
* This module implements IP dummynet, a bandwidth limiter/delay emulator
* used in conjunction with the ipfw package.
* Description of the data structures used is in ip_dummynet.h
* Here you mainly find the following blocks of code:
* + variable declarations;
* + heap management functions;
* + scheduler and dummynet functions;
* + configuration and initialization.
*
* NOTA BENE: critical sections are protected by splimp()/splx()
* pairs. One would think that splnet() is enough as for most of
* the netinet code, but it is not so because when used with
* bridging, dummynet is invoked at splimp().
*
* Most important Changes:
*
* 010122: Fixed spl protection.
* 000601: WF2Q+ support
* 000106: large rewrite, use heaps to handle very many pipes.
* 980513: initial release
@ -213,6 +225,12 @@ heap_init(struct dn_heap *h, int new_size)
#define SET_OFFSET(heap, node) \
if (heap->offset > 0) \
*((int *)((char *)(heap->p[node].object) + heap->offset)) = node ;
/*
* RESET_OFFSET is used for sanity checks. It sets offset to an invalid value.
*/
#define RESET_OFFSET(heap, node) \
if (heap->offset > 0) \
*((int *)((char *)(heap->p[node].object) + heap->offset)) = -1 ;
static int
heap_insert(struct dn_heap *h, dn_key key1, void *p)
{
@ -261,6 +279,12 @@ heap_extract(struct dn_heap *h, void *obj)
return ; /* or maybe panic... */
}
father = *((int *)((char *)obj + h->offset)) ;
if (father < 0 || father >= h->elements) {
printf("dummynet: heap_extract, father %d out of bound 0..%d\n",
father, h->elements);
panic("heap_extract");
}
RESET_OFFSET(h, father);
}
child = HEAP_LEFT(father) ; /* left child */
while (child <= max) { /* valid entry */
@ -557,7 +581,6 @@ ready_event_wfq(struct dn_pipe *p)
}
}
while ( sch->elements && p->numbytes >= 0 ) {
struct dn_heap *neh ;
u_int64_t normalized_service ;
@ -658,7 +681,7 @@ dummynet(void * __unused unused)
heaps[0] = &ready_heap ; /* fixed-rate queues */
heaps[1] = &wfq_ready_heap ; /* wfq queues */
heaps[2] = &extract_heap ; /* delay line */
s = splnet(); /* avoid network interrupts... */
s = splimp(); /* see note on top, splnet() is not enough */
curr_time++ ;
for (i=0; i < 3 ; i++) {
h = heaps[i];
@ -991,7 +1014,7 @@ dummynet_io(int pipe_nr, int dir, /* pipe_nr can also be a fs_nr */
struct dn_flow_queue *q = NULL ;
int s ;
s = splimp(); /* XXX might be unnecessary, we are already at splnet() */
s = splimp();
pipe_nr &= 0xffff ;
if ( (fs = rule->rule->pipe_ptr) == NULL ) {
@ -1068,8 +1091,13 @@ dummynet_io(int pipe_nr, int dir, /* pipe_nr can also be a fs_nr */
q->len++;
q->len_bytes += len ;
if ( q->head != pkt ) /* flow was not idle, we are done */
goto done;
if ( q->head != pkt ) { /* flow was not idle, we are done */
static int errors = 0 ;
if (q->blh_pos >= 0 ) /* good... */
goto done;
printf("+++ hey [%d] flow 0x%08x not idle but not in heap\n",
++errors, q);
}
/*
* The flow was previously idle, so we need to schedule it.
*/
@ -1207,7 +1235,7 @@ dummynet_flush()
struct dn_flow_set *fs, *curr_fs;
int s ;
s = splnet() ;
s = splimp() ;
/* remove all references to pipes ...*/
for (chain= ip_fw_chain.lh_first ; chain; chain = chain->chain.le_next)
@ -1440,7 +1468,7 @@ config_pipe(struct dn_pipe *p)
free(x, M_IPFW);
return s ;
}
s = splnet() ;
s = splimp() ;
x->next = b ;
if (a == NULL)
all_pipes = x ;
@ -1484,7 +1512,7 @@ config_pipe(struct dn_pipe *p)
free(x, M_IPFW);
return s ;
}
s = splnet() ;
s = splimp() ;
x->next = b;
if (a == NULL)
all_flow_sets = x;
@ -1582,7 +1610,7 @@ delete_pipe(struct dn_pipe *p)
if (b == NULL || (b->pipe_nr != p->pipe_nr) )
return EINVAL ; /* not found */
s = splnet() ;
s = splimp() ;
/* unlink from list of pipes */
if (a == NULL)
@ -1618,7 +1646,7 @@ delete_pipe(struct dn_pipe *p)
if (b == NULL || (b->fs_nr != p->fs.fs_nr) )
return EINVAL ; /* not found */
s = splnet() ;
s = splimp() ;
if (a == NULL)
all_flow_sets = b->next ;
else
@ -1683,7 +1711,7 @@ dummynet_get(struct sockopt *sopt)
struct dn_pipe *p ;
int s, error=0 ;
s = splnet() ; /* to avoid thing change while we work! */
s = splimp();
/*
* compute size of data structures: list of pipes and flow_sets.
*/
@ -1793,10 +1821,12 @@ ip_dn_init(void)
all_pipes = NULL ;
all_flow_sets = NULL ;
ready_heap.size = ready_heap.elements = 0 ;
ready_heap.offset = 0 ;
/* ready_heap.offset = 0 ; */
ready_heap.offset=OFFSET_OF(struct dn_flow_queue, blh_pos);
wfq_ready_heap.size = wfq_ready_heap.elements = 0 ;
wfq_ready_heap.offset = 0 ;
/* wfq_ready_heap.offset = 0 ; */
wfq_ready_heap.offset=OFFSET_OF(struct dn_flow_queue, blh_pos);
extract_heap.size = extract_heap.elements = 0 ;
extract_heap.offset = 0 ;
@ -1812,13 +1842,13 @@ dummynet_modevent(module_t mod, int type, void *data)
int s ;
switch (type) {
case MOD_LOAD:
s = splnet();
s = splimp();
old_dn_ctl_ptr = ip_dn_ctl_ptr;
ip_dn_init();
splx(s);
break;
case MOD_UNLOAD:
s = splnet();
s = splimp();
ip_dn_ctl_ptr = old_dn_ctl_ptr;
splx(s);
dummynet_flush();