+/*
+ * check whether we need to create more connds.
+ * It will try to create new thread if it's necessary, @timeout can
+ * be updated if failed to create, so caller wouldn't keep try while
+ * running out of resource.
+ */
+static int
+ksocknal_connd_check_start(long sec, long *timeout)
+{
+ int rc;
+ int total = ksocknal_data.ksnd_connd_starting +
+ ksocknal_data.ksnd_connd_running;
+
+ if (unlikely(ksocknal_data.ksnd_init < SOCKNAL_INIT_ALL)) {
+ /* still in initializing */
+ return 0;
+ }
+
+ if (total >= *ksocknal_tunables.ksnd_nconnds_max ||
+ total > ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV) {
+ /* can't create more connd, or still have enough
+ * threads to handle more connecting */
+ return 0;
+ }
+
+ if (list_empty(&ksocknal_data.ksnd_connd_routes)) {
+ /* no pending connecting request */
+ return 0;
+ }
+
+ if (sec - ksocknal_data.ksnd_connd_failed_stamp <= 1) {
+ /* may run out of resource, retry later */
+ *timeout = cfs_time_seconds(1);
+ return 0;
+ }
+
+ if (ksocknal_data.ksnd_connd_starting > 0) {
+ /* serialize starting to avoid flood */
+ return 0;
+ }
+
+ ksocknal_data.ksnd_connd_starting_stamp = sec;
+ ksocknal_data.ksnd_connd_starting++;
+ cfs_spin_unlock_bh(&ksocknal_data.ksnd_connd_lock);
+
+ /* NB: total is the next id */
+ rc = ksocknal_thread_start(ksocknal_connd, (void *)((long)total));
+
+ cfs_spin_lock_bh(&ksocknal_data.ksnd_connd_lock);
+ if (rc == 0)
+ return 1;
+
+ /* we tried ... */
+ LASSERT(ksocknal_data.ksnd_connd_starting > 0);
+ ksocknal_data.ksnd_connd_starting--;
+ ksocknal_data.ksnd_connd_failed_stamp = cfs_time_current_sec();
+
+ return 1;
+}
+
+/*
+ * check whether current thread can exit, it will return 1 if there are too
+ * many threads and no creating in past 120 seconds.
+ * Also, this function may update @timeout to make caller come back
+ * again to recheck these conditions.
+ */
+static int
+ksocknal_connd_check_stop(long sec, long *timeout)
+{
+ int val;
+
+ if (unlikely(ksocknal_data.ksnd_init < SOCKNAL_INIT_ALL)) {
+ /* still in initializing */
+ return 0;
+ }
+
+ if (ksocknal_data.ksnd_connd_starting > 0) {
+ /* in progress of starting new thread */
+ return 0;
+ }
+
+ if (ksocknal_data.ksnd_connd_running <=
+ *ksocknal_tunables.ksnd_nconnds) { /* can't shrink */
+ return 0;
+ }
+
+ /* created thread in past 120 seconds? */
+ val = (int)(ksocknal_data.ksnd_connd_starting_stamp +
+ SOCKNAL_CONND_TIMEOUT - sec);
+
+ *timeout = (val > 0) ? cfs_time_seconds(val) :
+ cfs_time_seconds(SOCKNAL_CONND_TIMEOUT);
+ if (val > 0)
+ return 0;
+
+ /* no creating in past 120 seconds */
+
+ return ksocknal_data.ksnd_connd_running >
+ ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV;
+}
+
+/* Go through connd_routes queue looking for a route that we can process
+ * right now, @timeout_p can be updated if we need to come back later */
git://git.whamcloud.com / fs / lustre-release.git / commitdiff