rds_rdma: do not dealloc fmrs in the pool under use

In rds_ib_alloc_fmr, when it needs flush pools, it de-allocates FMRs.
That is time-consuming and is not meaningful in functionality perspective.

Fix is to not de-allocate the ones in the pool which is under use.

Orabug: 21551548

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Chien-Hua Yen <chien.yen@oracle.com>

diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index 7083165202cc5dbda51ef86bf7957ac2896775fa..d31700f4d1badedfa9ca2b344ced8482485f52d7 100644 (file)
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -379,41 +379,49 @@ static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev,
                         IB_ACCESS_REMOTE_ATOMIC),
                        &pool->fmr_attr);
        if (IS_ERR(ibmr->fmr)) {
+               int total_pool_size;
+               int prev_8k_max;
+               int prev_1m_max;
+
                err = PTR_ERR(ibmr->fmr);
+               ibmr->fmr = NULL;
+               if (err != -ENOMEM)
+                       goto out_no_cigar;
 
                /* Re-balance the pool sizes to reflect the memory resources
                 * available to the VM.
                 */
-               if (err == -ENOMEM) {
-                       int total_pool_size =
-                               atomic_read(&rds_ibdev->mr_8k_pool->item_count)
-                                       * (RDS_FMR_8K_MSG_SIZE + 1) +
-                               atomic_read(&rds_ibdev->mr_1m_pool->item_count)
-                                       * RDS_FMR_1M_MSG_SIZE;
-
-                       if (total_pool_size) {
-                               int prev_8k_max = atomic_read(&rds_ibdev->mr_8k_pool->max_items_soft);
-                               int prev_1m_max = atomic_read(&rds_ibdev->mr_1m_pool->max_items_soft);
-                               atomic_set(&rds_ibdev->mr_8k_pool->max_items_soft, (total_pool_size / 4) / (RDS_FMR_8K_MSG_SIZE + 1));
-                               atomic_set(&rds_ibdev->mr_1m_pool->max_items_soft, (total_pool_size * 3 / 4) / RDS_FMR_1M_MSG_SIZE);
-                               printk(KERN_ERR "RDS/IB: "
-                                       "Adjusted 8K FMR pool (%d->%d)\n",
-                                       prev_8k_max,
-                                       atomic_read(&rds_ibdev->mr_8k_pool->max_items_soft));
-                               printk(KERN_ERR "RDS/IB: "
-                                       "Adjusted 1K FMR pool (%d->%d)\n",
-                                       prev_1m_max,
-                                       atomic_read(&rds_ibdev->mr_1m_pool->max_items_soft));
-                               rds_ib_flush_mr_pool(rds_ibdev->mr_8k_pool, 1,
-                                                       NULL);
-
-                               rds_ib_flush_mr_pool(rds_ibdev->mr_1m_pool, 1,
-                                                       NULL);
-
-                               err = -EAGAIN;
-                       }
+               total_pool_size =
+                       atomic_read(&rds_ibdev->mr_8k_pool->item_count)
+                               * (RDS_FMR_8K_MSG_SIZE + 1) +
+                       atomic_read(&rds_ibdev->mr_1m_pool->item_count)
+                               * RDS_FMR_1M_MSG_SIZE;
+
+               if (!total_pool_size)
+                       goto out_no_cigar;
+
+               prev_8k_max = atomic_read(
+                               &rds_ibdev->mr_8k_pool->max_items_soft);
+               prev_1m_max = atomic_read(
+                               &rds_ibdev->mr_1m_pool->max_items_soft);
+               atomic_set(&rds_ibdev->mr_8k_pool->max_items_soft,
+                          (total_pool_size / 4) / (RDS_FMR_8K_MSG_SIZE + 1));
+               atomic_set(&rds_ibdev->mr_1m_pool->max_items_soft,
+                          (total_pool_size * 3 / 4) / RDS_FMR_1M_MSG_SIZE);
+               printk(KERN_ERR "RDS/IB: Adjusted 8K FMR pool (%d->%d)\n",
+                      prev_8k_max,
+                      atomic_read(&rds_ibdev->mr_8k_pool->max_items_soft));
+               printk(KERN_ERR "RDS/IB: Adjusted 1M FMR pool (%d->%d)\n",
+                      prev_1m_max,
+                      atomic_read(&rds_ibdev->mr_1m_pool->max_items_soft));
+               if (pool == rds_ibdev->mr_1m_pool) {
+                       rds_ib_flush_mr_pool(rds_ibdev->mr_1m_pool, 0, NULL);
+                       rds_ib_flush_mr_pool(rds_ibdev->mr_8k_pool, 1, NULL);
+               } else {
+                       rds_ib_flush_mr_pool(rds_ibdev->mr_1m_pool, 1, NULL);
+                       rds_ib_flush_mr_pool(rds_ibdev->mr_8k_pool, 0, NULL);
                }
-               ibmr->fmr = NULL;
+               err = -EAGAIN;
                goto out_no_cigar;
        }