summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorJ. Bruce Fields <bfields@citi.umich.edu>2009-08-06 15:41:34 -0400
committerJ. Bruce Fields <bfields@citi.umich.edu>2009-11-23 12:34:05 -0500
commit78c210efdefe07131f91ed512a3308b15bb14e2f (patch)
tree8b101c92584e27b0dbe238f6a1208308e54dac81
parent0a3adadee42f2865bb867b8c5f4955b7def9baad (diff)
downloadlinux-78c210efdefe07131f91ed512a3308b15bb14e2f.tar.bz2
Revert "knfsd: avoid overloading the CPU scheduler with enormous load averages"
This reverts commit 59a252ff8c0f2fa32c896f69d56ae33e641ce7ad. This helps in an entirely cached workload but not necessarily in workloads that require waiting on disk. Conflicts: include/linux/sunrpc/svc.h net/sunrpc/svc_xprt.c Reported-by: Simon Kirby <sim@hostway.ca> Tested-by: Jesper Krogh <jesper@krogh.cc> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
-rw-r--r--include/linux/sunrpc/svc.h3
-rw-r--r--net/sunrpc/svc_xprt.c31
2 files changed, 9 insertions, 25 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 52e8cb0a7569..d1567d627557 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -29,7 +29,6 @@ struct svc_pool_stats {
unsigned long packets;
unsigned long sockets_queued;
unsigned long threads_woken;
- unsigned long overloads_avoided;
unsigned long threads_timedout;
};
@@ -50,7 +49,6 @@ 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 */
struct svc_pool_stats sp_stats; /* statistics on pool operation */
} ____cacheline_aligned_in_smp;
@@ -284,7 +282,6 @@ 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 df124f78ee48..2c58b75a236f 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -16,8 +16,6 @@
#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);
@@ -306,7 +304,6 @@ 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))))
@@ -318,6 +315,12 @@ 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);
@@ -358,15 +361,7 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
}
process:
- /* 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;
- pool->sp_stats.overloads_avoided++;
- }
-
- if (thread_avail) {
+ if (!list_empty(&pool->sp_threads)) {
rqstp = list_entry(pool->sp_threads.next,
struct svc_rqst,
rq_list);
@@ -381,8 +376,6 @@ 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++;
pool->sp_stats.threads_woken++;
BUG_ON(xprt->xpt_pool != pool);
wake_up(&rqstp->rq_wait);
@@ -651,11 +644,6 @@ 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;
@@ -1204,16 +1192,15 @@ static int svc_pool_stats_show(struct seq_file *m, void *p)
struct svc_pool *pool = p;
if (p == SEQ_START_TOKEN) {
- seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken overloads-avoided threads-timedout\n");
+ seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken threads-timedout\n");
return 0;
}
- seq_printf(m, "%u %lu %lu %lu %lu %lu\n",
+ seq_printf(m, "%u %lu %lu %lu %lu\n",
pool->sp_id,
pool->sp_stats.packets,
pool->sp_stats.sockets_queued,
pool->sp_stats.threads_woken,
- pool->sp_stats.overloads_avoided,
pool->sp_stats.threads_timedout);
return 0;