From 9e20ae339721d614a1b0768c48bd73b456ff7905 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Thu, 3 Oct 2013 14:03:59 -0700 Subject: iscsi-target; Allow an extra tag_num / 2 number of percpu_ida tags This patch bumps the default number of tags allocated per session by iscsi-target via transport_alloc_session_tags() -> percpu_ida_init() by another (tag_num / 2). This is done to take into account the tags waiting to be acknowledged and released in iscsit_ack_from_expstatsn(), but who's number are not directly limited by the CmdSN Window queue_depth being enforced by the target. Using a larger value here is also useful to prevent percpu_ida_alloc() from having to steal tags from other CPUs when no tags are available on the local CPU, while waiting for unacknowledged tags to be released. Signed-off-by: Nicholas Bellinger --- drivers/target/iscsi/iscsi_target_nego.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c index 14d1aed5af1d..ef6d836a4d09 100644 --- a/drivers/target/iscsi/iscsi_target_nego.c +++ b/drivers/target/iscsi/iscsi_target_nego.c @@ -1192,7 +1192,7 @@ get_target: */ alloc_tags: tag_num = max_t(u32, ISCSIT_MIN_TAGS, queue_depth); - tag_num += ISCSIT_EXTRA_TAGS; + tag_num += (tag_num / 2) + ISCSIT_EXTRA_TAGS; tag_size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size; ret = transport_alloc_session_tags(sess->se_sess, tag_num, tag_size); -- cgit v1.2.1