[PATCH 4/6] RDS: push FMR pool flush work to its own worker

From: Santosh Shilimkar
Date: Tue Aug 25 2015 - 15:02:29 EST


RDS FMR flush operation and also it races with connect/reconect
which happes a lot with RDS. FMR flush being on common rds_wq aggrevates
the problem. Lets push RDS FMR pool flush work to its own worker.

Signed-off-by: Santosh Shilimkar <ssantosh@xxxxxxxxxx>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
---
net/rds/ib.c | 9 ++++++++-
net/rds/ib.h | 2 ++
net/rds/ib_rdma.c | 27 ++++++++++++++++++++++++---
3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/net/rds/ib.c b/net/rds/ib.c
index ba2dffe..b5f7336 100644
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -366,6 +366,7 @@ void rds_ib_exit(void)
rds_ib_sysctl_exit();
rds_ib_recv_exit();
rds_trans_unregister(&rds_ib_transport);
+ rds_ib_fmr_exit();
}

struct rds_transport rds_ib_transport = {
@@ -401,10 +402,14 @@ int rds_ib_init(void)

INIT_LIST_HEAD(&rds_ib_devices);

- ret = ib_register_client(&rds_ib_client);
+ ret = rds_ib_fmr_init();
if (ret)
goto out;

+ ret = ib_register_client(&rds_ib_client);
+ if (ret)
+ goto out_fmr_exit;
+
ret = rds_ib_sysctl_init();
if (ret)
goto out_ibreg;
@@ -427,6 +432,8 @@ out_sysctl:
rds_ib_sysctl_exit();
out_ibreg:
rds_ib_unregister_client();
+out_fmr_exit:
+ rds_ib_fmr_exit();
out:
return ret;
}
diff --git a/net/rds/ib.h b/net/rds/ib.h
index 6422c52..9fc95e3 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -313,6 +313,8 @@ void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
void rds_ib_sync_mr(void *trans_private, int dir);
void rds_ib_free_mr(void *trans_private, int invalidate);
void rds_ib_flush_mrs(void);
+int rds_ib_fmr_init(void);
+void rds_ib_fmr_exit(void);

/* ib_recv.c */
int rds_ib_recv_init(void);
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index a275b7d..2ac78c9 100644
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -83,6 +83,25 @@ struct rds_ib_mr_pool {
struct ib_fmr_attr fmr_attr;
};

+struct workqueue_struct *rds_ib_fmr_wq;
+
+int rds_ib_fmr_init(void)
+{
+ rds_ib_fmr_wq = create_workqueue("rds_fmr_flushd");
+ if (!rds_ib_fmr_wq)
+ return -ENOMEM;
+ return 0;
+}
+
+/* By the time this is called all the IB devices should have been torn down and
+ * had their pools freed. As each pool is freed its work struct is waited on,
+ * so the pool flushing work queue should be idle by the time we get here.
+ */
+void rds_ib_fmr_exit(void)
+{
+ destroy_workqueue(rds_ib_fmr_wq);
+}
+
static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all, struct rds_ib_mr **);
static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr);
static void rds_ib_mr_pool_flush_worker(struct work_struct *work);
@@ -719,15 +738,17 @@ void rds_ib_free_mr(void *trans_private, int invalidate)
/* If we've pinned too many pages, request a flush */
if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
atomic_read(&pool->dirty_count) >= pool->max_items / 10)
- schedule_delayed_work(&pool->flush_worker, 10);
+ queue_delayed_work(rds_ib_fmr_wq, &pool->flush_worker, 10);

if (invalidate) {
if (likely(!in_interrupt())) {
rds_ib_flush_mr_pool(pool, 0, NULL);
} else {
/* We get here if the user created a MR marked
- * as use_once and invalidate at the same time. */
- schedule_delayed_work(&pool->flush_worker, 10);
+ * as use_once and invalidate at the same time.
+ */
+ queue_delayed_work(rds_ib_fmr_wq,
+ &pool->flush_worker, 10);
}
}

--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/