From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
If the cache is completely out of MRs, and we are running in cache mode,
then directly, and synchronously, create an MR that is compatible with the
cache bucket using a sleeping mailbox command. This ensures that the
thread that is waiting for the MR absolutely will get one.
When a MR allocated in this way becomes freed then it is compatible with
the cache bucket and will be recycled back into it.
Deletes the very buggy ent->compl scheme to create a synchronous MR
allocation.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
drivers/infiniband/hw/mlx5/mlx5_ib.h | 1 -
drivers/infiniband/hw/mlx5/mr.c | 173 ++++++++++++++++-----------
2 files changed, 105 insertions(+), 69 deletions(-)
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index e997837e600c..0ea8d57827fb 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -726,7 +726,6 @@ struct mlx5_cache_ent {
struct mlx5_ib_dev *dev;
struct work_struct work;
struct delayed_work dwork;
- struct completion compl;
};
struct mlx5_mr_cache {
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index c15de55c5a73..e64ac5a8434e 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -89,13 +89,29 @@ static int create_mkey_cb(struct mlx5_core_dev *dev, struct mlx5_ib_mr *mr,
callback, &mr->cb_work);
}
+static void finalize_new_mr(struct mlx5_ib_mr *mr)
+{
+ struct mlx5_ib_dev *dev = mr->dev;
+ unsigned long flags;
+ u8 key;
+
+ mr->mmkey.type = MLX5_MKEY_MR;
+ spin_lock_irqsave(&dev->mdev->priv.mkey_lock, flags);
+ key = dev->mdev->priv.mkey_key++;
+ spin_unlock_irqrestore(&dev->mdev->priv.mkey_lock, flags);
+ mr->mmkey.key = mlx5_idx_to_mkey(MLX5_GET(create_mkey_out, mr->out,
+ mkey_index)) |
+ key;
+
+ WRITE_ONCE(dev->cache.last_add, jiffies);
+}
+
static void reg_mr_callback(int status, struct mlx5_async_work *context)
{
struct mlx5_ib_mr *mr =
container_of(context, struct mlx5_ib_mr, cb_work);
struct mlx5_ib_dev *dev = mr->dev;
struct mlx5_cache_ent *ent = mr->cache_ent;
- u8 key;
unsigned long flags;
if (status) {
@@ -109,13 +125,7 @@ static void reg_mr_callback(int status, struct mlx5_async_work *context)
return;
}
- mr->mmkey.type = MLX5_MKEY_MR;
- spin_lock_irqsave(&dev->mdev->priv.mkey_lock, flags);
- key = dev->mdev->priv.mkey_key++;
- spin_unlock_irqrestore(&dev->mdev->priv.mkey_lock, flags);
- mr->mmkey.key = mlx5_idx_to_mkey(MLX5_GET(create_mkey_out, mr->out, mkey_index)) | key;
-
- WRITE_ONCE(dev->cache.last_add, jiffies);
+ finalize_new_mr(mr);
spin_lock_irqsave(&ent->lock, flags);
list_add_tail(&mr->list, &ent->head);
@@ -125,14 +135,34 @@ static void reg_mr_callback(int status, struct mlx5_async_work *context)
queue_adjust_cache_locked(ent);
ent->pending--;
spin_unlock_irqrestore(&ent->lock, flags);
+}
+
+static struct mlx5_ib_mr *alloc_cache_mr(struct mlx5_cache_ent *ent, void *mkc)
+{
+ struct mlx5_ib_mr *mr;
+
+ mr = kzalloc(sizeof(*mr), GFP_KERNEL);
+ if (!mr)
+ return NULL;
+ mr->order = ent->order;
+ mr->cache_ent = ent;
+ mr->dev = ent->dev;
- if (!completion_done(&ent->compl))
- complete(&ent->compl);
+ MLX5_SET(mkc, mkc, free, 1);
+ MLX5_SET(mkc, mkc, umr_en, 1);
+ MLX5_SET(mkc, mkc, access_mode_1_0, ent->access_mode & 0x3);
+ MLX5_SET(mkc, mkc, access_mode_4_2, (ent->access_mode >> 2) & 0x7);
+
+ MLX5_SET(mkc, mkc, qpn, 0xffffff);
+ MLX5_SET(mkc, mkc, translations_octword_size, ent->xlt);
+ MLX5_SET(mkc, mkc, log_page_size, ent->page);
+ return mr;
}
+/* Asynchronously schedule new MRs to be populated in the cache. */
static int add_keys(struct mlx5_cache_ent *ent, unsigned int num)
{
- int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
+ size_t inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
struct mlx5_ib_mr *mr;
void *mkc;
u32 *in;
@@ -145,25 +175,11 @@ static int add_keys(struct mlx5_cache_ent *ent, unsigned int num)
mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
for (i = 0; i < num; i++) {
- mr = kzalloc(sizeof(*mr), GFP_KERNEL);
+ mr = alloc_cache_mr(ent, mkc);
if (!mr) {
err = -ENOMEM;
break;
}
- mr->order = ent->order;
- mr->cache_ent = ent;
- mr->dev = ent->dev;
-
- MLX5_SET(mkc, mkc, free, 1);
- MLX5_SET(mkc, mkc, umr_en, 1);
- MLX5_SET(mkc, mkc, access_mode_1_0, ent->access_mode & 0x3);
- MLX5_SET(mkc, mkc, access_mode_4_2,
- (ent->access_mode >> 2) & 0x7);
-
- MLX5_SET(mkc, mkc, qpn, 0xffffff);
- MLX5_SET(mkc, mkc, translations_octword_size, ent->xlt);
- MLX5_SET(mkc, mkc, log_page_size, ent->page);
-
spin_lock_irq(&ent->lock);
if (ent->pending >= MAX_PENDING_REG_MR) {
err = -EAGAIN;
@@ -190,6 +206,44 @@ static int add_keys(struct mlx5_cache_ent *ent, unsigned int num)
return err;
}
+/* Synchronously create a MR in the cache */
+static struct mlx5_ib_mr *create_cache_mr(struct mlx5_cache_ent *ent)
+{
+ size_t inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
+ struct mlx5_ib_mr *mr;
+ void *mkc;
+ u32 *in;
+ int err;
+
+ in = kzalloc(inlen, GFP_KERNEL);
+ if (!in)
+ return ERR_PTR(-ENOMEM);
+ mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+
+ mr = alloc_cache_mr(ent, mkc);
+ if (!mr) {
+ err = -ENOMEM;
+ goto free_in;
+ }
+
+ err = mlx5_core_create_mkey(ent->dev->mdev, &mr->mmkey, in, inlen);
+ if (err)
+ goto free_mr;
+
+ mr->mmkey.type = MLX5_MKEY_MR;
+ WRITE_ONCE(ent->dev->cache.last_add, jiffies);
+ spin_lock_irq(&ent->lock);
+ ent->total_mrs++;
+ spin_unlock_irq(&ent->lock);
+ kfree(in);
+ return mr;
+free_mr:
+ kfree(mr);
+free_in:
+ kfree(in);
+ return ERR_PTR(err);
+}
+
static void remove_cache_mr_locked(struct mlx5_cache_ent *ent)
{
struct mlx5_ib_mr *mr;
@@ -412,12 +466,12 @@ static void __cache_work_func(struct mlx5_cache_ent *ent)
if (ent->disabled)
goto out;
if (err) {
- if (err == -EAGAIN) {
- mlx5_ib_dbg(dev, "returned eagain, order %d\n",
- ent->order);
- queue_delayed_work(cache->wq, &ent->dwork,
- msecs_to_jiffies(3));
- } else {
+ /*
+ * EAGAIN only happens if pending is positive, so we
+ * will be rescheduled from reg_mr_callback(). The only
+ * failure path here is ENOMEM.
+ */
+ if (err != -EAGAIN) {
mlx5_ib_warn(
dev,
"command failed order %d, err %d\n",
@@ -480,36 +534,30 @@ struct mlx5_ib_mr *mlx5_mr_cache_alloc(struct mlx5_ib_dev *dev,
struct mlx5_mr_cache *cache = &dev->cache;
struct mlx5_cache_ent *ent;
struct mlx5_ib_mr *mr;
- int err;
if (WARN_ON(entry <= MR_CACHE_LAST_STD_ENTRY ||
entry >= ARRAY_SIZE(cache->ent)))
return ERR_PTR(-EINVAL);
ent = &cache->ent[entry];
- while (1) {
- spin_lock_irq(&ent->lock);
- if (list_empty(&ent->head)) {
- spin_unlock_irq(&ent->lock);
-
- err = add_keys(ent, 1);
- if (err && err != -EAGAIN)
- return ERR_PTR(err);
-
- wait_for_completion(&ent->compl);
- } else {
- mr = list_first_entry(&ent->head, struct mlx5_ib_mr,
- list);
- list_del(&mr->list);
- ent->available_mrs--;
- queue_adjust_cache_locked(ent);
- spin_unlock_irq(&ent->lock);
+ spin_lock_irq(&ent->lock);
+ if (list_empty(&ent->head)) {
+ spin_unlock_irq(&ent->lock);
+ mr = create_cache_mr(ent);
+ if (IS_ERR(mr))
return mr;
- }
+ } else {
+ mr = list_first_entry(&ent->head, struct mlx5_ib_mr, list);
+ list_del(&mr->list);
+ ent->available_mrs--;
+ queue_adjust_cache_locked(ent);
+ spin_unlock_irq(&ent->lock);
}
+ return mr;
}
-static struct mlx5_ib_mr *alloc_cached_mr(struct mlx5_cache_ent *req_ent)
+/* Return a MR already available in the cache */
+static struct mlx5_ib_mr *get_cache_mr(struct mlx5_cache_ent *req_ent)
{
struct mlx5_ib_dev *dev = req_ent->dev;
struct mlx5_ib_mr *mr = NULL;
@@ -661,7 +709,6 @@ int mlx5_mr_cache_init(struct mlx5_ib_dev *dev)
ent->dev = dev;
ent->limit = 0;
- init_completion(&ent->compl);
INIT_WORK(&ent->work, cache_work_func);
INIT_DELAYED_WORK(&ent->dwork, delayed_cache_work_func);
@@ -925,26 +972,16 @@ alloc_mr_from_cache(struct ib_pd *pd, struct ib_umem *umem, u64 virt_addr,
struct mlx5_ib_dev *dev = to_mdev(pd->device);
struct mlx5_cache_ent *ent = mr_cache_ent_from_order(dev, order);
struct mlx5_ib_mr *mr;
- int err = 0;
- int i;
if (!ent)
return ERR_PTR(-E2BIG);
- for (i = 0; i < 1; i++) {
- mr = alloc_cached_mr(ent);
- if (mr)
- break;
-
- err = add_keys(ent, 1);
- if (err && err != -EAGAIN) {
- mlx5_ib_warn(dev, "add_keys failed, err %d\n", err);
- break;
- }
+ mr = get_cache_mr(ent);
+ if (!mr) {
+ mr = create_cache_mr(ent);
+ if (IS_ERR(mr))
+ return mr;
}
- if (!mr)
- return ERR_PTR(-EAGAIN);
-
mr->ibmr.pd = pd;
mr->umem = umem;
mr->access_flags = access_flags;
--
2.24.1
