To avoid one doubtless netgraph SMP scalability limitation point, switch

node queues processing from single swi:net thread to several specialized
threads.

Reviewed by:	julian
Tested with:	Netperf Cluster
This commit is contained in:
Alexander Motin 2008-12-14 20:15:30 +00:00
parent f7e148e30d
commit f2fbb83858
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=186093

View File

@ -62,6 +62,9 @@
#include <sys/refcount.h>
#include <sys/proc.h>
#include <sys/vimage.h>
#include <sys/unistd.h>
#include <sys/kthread.h>
#include <sys/smp.h>
#include <machine/cpu.h>
#include <net/netisr.h>
@ -211,7 +214,7 @@ static int ng_generic_msg(node_p here, item_p item, hook_p lasthook);
static ng_ID_t ng_decodeidname(const char *name);
static int ngb_mod_event(module_t mod, int event, void *data);
static void ng_worklist_add(node_p node);
static void ngintr(void);
static void ngthread(void *);
static int ng_apply_item(node_p node, item_p item, int rw);
static void ng_flush_input_queue(node_p node);
static node_p ng_ID2noderef(ng_ID_t ID);
@ -259,6 +262,10 @@ MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
mtx_lock(&ng_worklist_mtx)
#define NG_WORKLIST_UNLOCK() \
mtx_unlock(&ng_worklist_mtx)
#define NG_WORKLIST_SLEEP() \
mtx_sleep(&ng_worklist, &ng_worklist_mtx, PI_NET, "sleep", 0)
#define NG_WORKLIST_WAKEUP() \
wakeup_one(&ng_worklist)
#ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
/*
@ -2868,9 +2875,13 @@ ng_generic_msg(node_p here, item_p item, hook_p lasthook)
uma_zone_t ng_qzone;
uma_zone_t ng_qdzone;
static int numthreads = 0; /* number of queue threads */
static int maxalloc = 4096;/* limit the damage of a leak */
static int maxdata = 512; /* limit the damage of a DoS */
TUNABLE_INT("net.graph.threads", &numthreads);
SYSCTL_INT(_net_graph, OID_AUTO, threads, CTLFLAG_RDTUN, &numthreads,
0, "Number of queue processing threads");
TUNABLE_INT("net.graph.maxalloc", &maxalloc);
SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RDTUN, &maxalloc,
0, "Maximum number of non-data queue items to allocate");
@ -3064,7 +3075,9 @@ ng_mod_event(module_t mod, int event, void *data)
static int
ngb_mod_event(module_t mod, int event, void *data)
{
int error = 0;
struct proc *p;
struct thread *td;
int i, error = 0;
switch (event) {
case MOD_LOAD:
@ -3091,7 +3104,18 @@ ngb_mod_event(module_t mod, int event, void *data)
ng_qdzone = uma_zcreate("NetGraph data items", sizeof(struct ng_item),
NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
uma_zone_set_max(ng_qdzone, maxdata);
netisr_register(NETISR_NETGRAPH, (netisr_t *)ngintr, NULL, 0);
/* Autoconfigure number of threads. */
if (numthreads <= 0)
numthreads = mp_ncpus;
/* Create threads. */
p = NULL; /* start with no process */
for (i = 0; i < numthreads; i++) {
if (kproc_kthread_add(ngthread, NULL, &p, &td,
RFHIGHPID, 0, "ng_queue", "ng_queue%d", i)) {
numthreads = i;
break;
}
}
break;
case MOD_UNLOAD:
/* You can't unload it because an interface may be using it. */
@ -3246,25 +3270,20 @@ SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items, CTLTYPE_INT | CTLFLAG_RW,
/***********************************************************************
* Worklist routines
**********************************************************************/
/* NETISR thread enters here */
/*
* Pick a node off the list of nodes with work,
* try get an item to process off it.
* If there are no more, remove the node from the list.
* try get an item to process off it. Remove the node from the list.
*/
static void
ngintr(void)
ngthread(void *arg)
{
for (;;) {
node_p node;
/* Get node from the worklist. */
NG_WORKLIST_LOCK();
node = STAILQ_FIRST(&ng_worklist);
if (!node) {
NG_WORKLIST_UNLOCK();
break;
}
while ((node = STAILQ_FIRST(&ng_worklist)) == NULL)
NG_WORKLIST_SLEEP();
STAILQ_REMOVE_HEAD(&ng_worklist, nd_input_queue.q_work);
NG_WORKLIST_UNLOCK();
CTR3(KTR_NET, "%20s: node [%x] (%p) taken off worklist",
@ -3320,9 +3339,9 @@ ng_worklist_add(node_p node)
NG_WORKLIST_LOCK();
STAILQ_INSERT_TAIL(&ng_worklist, node, nd_input_queue.q_work);
NG_WORKLIST_UNLOCK();
schednetisr(NETISR_NETGRAPH);
CTR3(KTR_NET, "%20s: node [%x] (%p) put on worklist", __func__,
node->nd_ID, node);
NG_WORKLIST_WAKEUP();
} else {
CTR3(KTR_NET, "%20s: node [%x] (%p) already on worklist",
__func__, node->nd_ID, node);