Changeset 4352

Timestamp:

11/18/09 13:34:39 (8 months ago)

Author:

phk

Message:

Add a parameter to set the workerthread stacksize.

On 32 bit systems, it may be necessary to tweak this down to get high
numbers of worker threads squeezed into the address-space.

I have no idea how much stack-space a worker thread normally uses, so
no guidance is given, and we default to the system default.

Fixes #572

Location:

trunk/varnish-cache/bin/varnishd

Files:

• cache_pool.c (modified) (6 diffs)
• heritage.h (modified) (1 diff)
• mgt_pool.c (modified) (1 diff)

trunk/varnish-cache/bin/varnishd/cache_pool.c

@@ -433 +433 @@
 
 static void
-wrk_breed_flock(struct wq *qp)
+wrk_breed_flock(struct wq *qp, const pthread_attr_t *tp_attr)
 {
         pthread_t tp;
@@ -446 +446 @@
                 if (qp->nthr >= nthr_max) {
                         VSL_stats->n_wrk_max++;
-                } else if (pthread_create(&tp, NULL, wrk_thread, qp)) {
+                } else if (pthread_create(&tp, tp_attr, wrk_thread, qp)) {
                         VSL(SLT_Debug, 0, "Create worker thread failed %d %s",
                             errno, strerror(errno));
@@ -477 +477 @@
 {
         unsigned u, w;
+        pthread_attr_t tp_attr; 
+
+        /* Set the stacksize for worker threads */ 
+        AZ(pthread_attr_init(&tp_attr));
 
         THR_SetName("wrk_herder");
@@ -482 +486 @@
         while (1) {
                 for (u = 0 ; u < nwq; u++) {
+                        if (params->wthread_stacksize != UINT_MAX)
+                                AZ(pthread_attr_setstacksize(&tp_attr,
+                                    params->wthread_stacksize)); 
+
+                        wrk_breed_flock(wq[u], &tp_attr);
+
                         /*
                          * Make sure all pools have their minimum complement
@@ -487 +497 @@
                         for (w = 0 ; w < nwq; w++)
                                 while (wq[w]->nthr < params->wthread_min)
-                                        wrk_breed_flock(wq[w]);
+                                        wrk_breed_flock(wq[w], &tp_attr);
                         /*
                          * We cannot avoid getting a mutex, so we have a
@@ -495 +505 @@
                         Lck_CondWait(&herder_cond, &herder_mtx);
                         Lck_Unlock(&herder_mtx);
-                        wrk_breed_flock(wq[u]);
                 }
         }

trunk/varnish-cache/bin/varnishd/heritage.h

@@ -94 +94 @@
         unsigned                wthread_purge_delay;
         unsigned                wthread_stats_rate;
+        unsigned                wthread_stacksize;
 
         unsigned                overflow_max;

trunk/varnish-cache/bin/varnishd/mgt_pool.c

@@ -191 +191 @@
                 EXPERIMENTAL,
                 "3", "requests per request" },
+        { "thread_pool_stack",
+                tweak_uint, &master.wthread_stacksize, 64*1024, UINT_MAX,
+                "Worker thread stack size.  In particular on 32bit systems "
+                "you may need to tweak this down to fit many threads into "
+                "the limited address space.\n",
+                EXPERIMENTAL,
+                "-1", "bytes" },
         { NULL, NULL, NULL }
 };