From 5d26583158c39759d7e8295faabd5dc1f3a5be58 Mon Sep 17 00:00:00 2001
From: johann <johann>
Date: Fri, 28 Dec 2007 13:08:58 +0000
Subject: [PATCH] Branch b1_6 b=13843 i=adilger i=bowen.zhou
add a priority list for blocking callbacks.
---
lustre/ldlm/ldlm_lockd.c | 39 +++++++++++++++++++++++++++++++++++----
1 file changed, 35 insertions(+), 4 deletions(-)
diff --git a/lustre/ldlm/ldlm_lockd.c b/lustre/ldlm/ldlm_lockd.c
index 356582b3bf..2aa734e8de 100644
--- a/lustre/ldlm/ldlm_lockd.c
+++ b/lustre/ldlm/ldlm_lockd.c
@@ -89,7 +89,20 @@ static struct expired_lock_thread {
struct ldlm_bl_pool {
spinlock_t blp_lock;
+
+ /*
+ * blp_prio_list is used for callbacks that should be handled
+ * as a priority. It is used for LDLM_FL_DISCARD_DATA requests.
+ * see bug 13843
+ */
+ struct list_head blp_prio_list;
+
+ /*
+ * blp_list is used for all other callbacks which are likely
+ * to take longer to process.
+ */
struct list_head blp_list;
+
cfs_waitq_t blp_waitq;
struct completion blp_comp;
atomic_t blp_num_threads;
@@ -1397,7 +1410,13 @@ static int ldlm_bl_to_thread(struct ldlm_namespace *ns,
blwi->blwi_lock = lock;
}
spin_lock(&blp->blp_lock);
- list_add_tail(&blwi->blwi_entry, &blp->blp_list);
+ if (lock->l_flags & LDLM_FL_DISCARD_DATA) {
+ /* add LDLM_FL_DISCARD_DATA requests to the priority list */
+ list_add_tail(&blwi->blwi_entry, &blp->blp_prio_list);
+ } else {
+ /* other blocking callbacks are added to the regular list */
+ list_add_tail(&blwi->blwi_entry, &blp->blp_list);
+ }
cfs_waitq_signal(&blp->blp_waitq);
spin_unlock(&blp->blp_lock);
@@ -1644,11 +1663,22 @@ static int ldlm_cancel_handler(struct ptlrpc_request *req)
static struct ldlm_bl_work_item *ldlm_bl_get_work(struct ldlm_bl_pool *blp)
{
struct ldlm_bl_work_item *blwi = NULL;
+ static unsigned int num_bl = 0;
spin_lock(&blp->blp_lock);
- if (!list_empty(&blp->blp_list)) {
- blwi = list_entry(blp->blp_list.next, struct ldlm_bl_work_item,
- blwi_entry);
+ /* process a request from the blp_list at least every blp_num_threads */
+ if (!list_empty(&blp->blp_list) &&
+ (list_empty(&blp->blp_prio_list) || num_bl == 0))
+ blwi = list_entry(blp->blp_list.next,
+ struct ldlm_bl_work_item, blwi_entry);
+ else
+ if (!list_empty(&blp->blp_prio_list))
+ blwi = list_entry(blp->blp_prio_list.next,
+ struct ldlm_bl_work_item, blwi_entry);
+
+ if (blwi) {
+ if (++num_bl >= atomic_read(&blp->blp_num_threads))
+ num_bl = 0;
list_del(&blwi->blwi_entry);
}
spin_unlock(&blp->blp_lock);
@@ -1862,6 +1892,7 @@ static int ldlm_setup(void)
spin_lock_init(&blp->blp_lock);
CFS_INIT_LIST_HEAD(&blp->blp_list);
+ CFS_INIT_LIST_HEAD(&blp->blp_prio_list);
cfs_waitq_init(&blp->blp_waitq);
atomic_set(&blp->blp_num_threads, 0);
atomic_set(&blp->blp_busy_threads, 0);
--
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