LU-874 ldlm: Fix ldlm_bl_* thread creation

Always create a new ldlm_bl_ thread when all threads
are busy, not just after returning from sleep.

Change-Id: I2fa99a0f09a42e1333589fc7bc2a6eebef4924b6
Signed-off-by: Christopher J. Morrone <morrone2@llnl.gov>
Reviewed-on: http://review.whamcloud.com/1926
Tested-by: Hudson
Reviewed-by: Jinshan Xiong <jinshan.xiong@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Johann Lombardi <johann@whamcloud.com>

diff --git a/lustre/ldlm/ldlm_lockd.c b/lustre/ldlm/ldlm_lockd.c
index da9a6f7..2be5aa9 100644 (file)
--- a/lustre/ldlm/ldlm_lockd.c
+++ b/lustre/ldlm/ldlm_lockd.c
@@ -2230,33 +2230,31 @@ static int ldlm_bl_thread_main(void *arg)
         while (1) {
                 struct l_wait_info lwi = { 0 };
                 struct ldlm_bl_work_item *blwi = NULL;
+                int busy;
 
                 blwi = ldlm_bl_get_work(blp);
 
                 if (blwi == NULL) {
-                        int busy;
-
                         cfs_atomic_dec(&blp->blp_busy_threads);
                         l_wait_event_exclusive(blp->blp_waitq,
                                          (blwi = ldlm_bl_get_work(blp)) != NULL,
                                          &lwi);
                         busy = cfs_atomic_inc_return(&blp->blp_busy_threads);
-
-                        if (blwi->blwi_ns == NULL)
-                                /* added by ldlm_cleanup() */
-                                break;
-
-                        /* Not fatal if racy and have a few too many threads */
-                        if (unlikely(busy < blp->blp_max_threads &&
-                            busy >= cfs_atomic_read(&blp->blp_num_threads) &&
-                            !blwi->blwi_mem_pressure))
-                                /* discard the return value, we tried */
-                                ldlm_bl_thread_start(blp);
                 } else {
-                        if (blwi->blwi_ns == NULL)
-                                /* added by ldlm_cleanup() */
-                                break;
+                        busy = cfs_atomic_read(&blp->blp_busy_threads);
                 }
+
+                if (blwi->blwi_ns == NULL)
+                        /* added by ldlm_cleanup() */
+                        break;
+
+                /* Not fatal if racy and have a few too many threads */
+                if (unlikely(busy < blp->blp_max_threads &&
+                             busy >= cfs_atomic_read(&blp->blp_num_threads) &&
+                             !blwi->blwi_mem_pressure))
+                        /* discard the return value, we tried */
+                        ldlm_bl_thread_start(blp);
+
                 if (blwi->blwi_mem_pressure)
                         cfs_memory_pressure_set();