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-rw-r--r--include/linux/sunrpc/svc.h2
-rw-r--r--net/sunrpc/svc_xprt.c25
2 files changed, 20 insertions, 7 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 3435d24bfe5..39ec186a492 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -41,6 +41,7 @@ struct svc_pool {
struct list_head sp_sockets; /* pending sockets */
unsigned int sp_nrthreads; /* # of threads in pool */
struct list_head sp_all_threads; /* all server threads */
+ int sp_nwaking; /* number of threads woken but not yet active */
} ____cacheline_aligned_in_smp;
/*
@@ -264,6 +265,7 @@ struct svc_rqst {
* cache pages */
wait_queue_head_t rq_wait; /* synchronization */
struct task_struct *rq_task; /* service thread */
+ int rq_waking; /* 1 if thread is being woken */
};
/*
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index e588df5d6b3..0551b6b6cf8 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -14,6 +14,8 @@
#define RPCDBG_FACILITY RPCDBG_SVCXPRT
+#define SVC_MAX_WAKING 5
+
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
static int svc_deferred_recv(struct svc_rqst *rqstp);
static struct cache_deferred_req *svc_defer(struct cache_req *req);
@@ -298,6 +300,7 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
struct svc_pool *pool;
struct svc_rqst *rqstp;
int cpu;
+ int thread_avail;
if (!(xprt->xpt_flags &
((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED))))
@@ -309,12 +312,6 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
spin_lock_bh(&pool->sp_lock);
- if (!list_empty(&pool->sp_threads) &&
- !list_empty(&pool->sp_sockets))
- printk(KERN_ERR
- "svc_xprt_enqueue: "
- "threads and transports both waiting??\n");
-
if (test_bit(XPT_DEAD, &xprt->xpt_flags)) {
/* Don't enqueue dead transports */
dprintk("svc: transport %p is dead, not enqueued\n", xprt);
@@ -353,7 +350,14 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
}
process:
- if (!list_empty(&pool->sp_threads)) {
+ /* Work out whether threads are available */
+ thread_avail = !list_empty(&pool->sp_threads); /* threads are asleep */
+ if (pool->sp_nwaking >= SVC_MAX_WAKING) {
+ /* too many threads are runnable and trying to wake up */
+ thread_avail = 0;
+ }
+
+ if (thread_avail) {
rqstp = list_entry(pool->sp_threads.next,
struct svc_rqst,
rq_list);
@@ -368,6 +372,8 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
svc_xprt_get(xprt);
rqstp->rq_reserved = serv->sv_max_mesg;
atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
+ rqstp->rq_waking = 1;
+ pool->sp_nwaking++;
BUG_ON(xprt->xpt_pool != pool);
wake_up(&rqstp->rq_wait);
} else {
@@ -633,6 +639,11 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
return -EINTR;
spin_lock_bh(&pool->sp_lock);
+ if (rqstp->rq_waking) {
+ rqstp->rq_waking = 0;
+ pool->sp_nwaking--;
+ BUG_ON(pool->sp_nwaking < 0);
+ }
xprt = svc_xprt_dequeue(pool);
if (xprt) {
rqstp->rq_xprt = xprt;