From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 21 Aug 2012 15:01:50 +0000 (-0400)
Subject: Fix: rculfhash should be offline while waiting for resize to complete
X-Git-Tag: v0.7.4~2
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=285b448165d2685018eb6b73362fcd3c047c7921;p=userspace-rcu.git

Fix: rculfhash should be offline while waiting for resize to complete

Causes hang on destroy with urcu QSBR if destroy is called within a rcu
registered thread.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/rculfhash.c b/rculfhash.c
index 3ad3618..b8fbb64 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -1728,8 +1728,10 @@ int cds_lfht_destroy(struct cds_lfht *ht, pthread_attr_t **attr)
 	/* Wait for in-flight resize operations to complete */
 	_CMM_STORE_SHARED(ht->in_progress_destroy, 1);
 	cmm_smp_mb();	/* Store destroy before load resize */
+	ht->flavor->thread_offline();
 	while (uatomic_read(&ht->in_progress_resize))
 		poll(NULL, 0, 100);	/* wait for 100ms */
+	ht->flavor->thread_online();
 	ret = cds_lfht_delete_bucket(ht);
 	if (ret)
 		return ret;