[PATCH rdma-next 3/7] RDMA/mlx5: Store in the cache mkeys instead of mrs

Leon Romanovsky
2021-12-06T09:11:15Z

Currently, the driver stores the entire mlx5_ib_mr struct in the cache,
although the only use of the cached MR is the mkey. Store only the mkey
in the cache.

Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
drivers/infiniband/hw/mlx5/mlx5_ib.h | 21 ++---
drivers/infiniband/hw/mlx5/mr.c | 135 +++++++++++++--------------
2 files changed, 71 insertions(+), 85 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index d0224f468169..9b12e970ca01 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -668,14 +668,6 @@ struct mlx5_ib_mr {

/* This is zero'd when the MR is allocated */
union {
- /* Used only while the MR is in the cache */
- struct {
- u32 out[MLX5_ST_SZ_DW(create_mkey_out)];
- struct mlx5_async_work cb_work;
- /* Cache list element */
- struct list_head list;
- };
-
/* Used only by kernel MRs (umem == NULL) */
struct {
void *descs;
@@ -715,12 +707,6 @@ struct mlx5_ib_mr {
};
};

-/* Zero the fields in the mr that are variant depending on usage */
-static inline void mlx5_clear_mr(struct mlx5_ib_mr *mr)
-{
- memset(mr->out, 0, sizeof(*mr) - offsetof(struct mlx5_ib_mr, out));
-}
-
static inline bool is_odp_mr(struct mlx5_ib_mr *mr)
{
return IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && mr->umem &&
@@ -786,6 +772,13 @@ struct mlx5_cache_ent {
struct delayed_work dwork;
};

+struct mlx5_async_create_mkey {
+ u32 out[MLX5_ST_SZ_DW(create_mkey_out)];
+ struct mlx5_async_work cb_work;
+ struct mlx5_cache_ent *ent;
+ u32 mkey;
+};
+
struct mlx5_mr_cache {
struct workqueue_struct *wq;
struct mlx5_cache_ent ent[MAX_MR_CACHE_ENTRIES];
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index e62f8da8558d..e64f6466f13d 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -88,15 +88,14 @@ static void set_mkc_access_pd_addr_fields(void *mkc, int acc, u64 start_addr,
MLX5_SET64(mkc, mkc, start_addr, start_addr);
}

-static void assign_mkey_variant(struct mlx5_ib_dev *dev,
- struct mlx5_ib_mkey *mkey, u32 *in)
+static void assign_mkey_variant(struct mlx5_ib_dev *dev, u32 *mkey, u32 *in)
{
u8 key = atomic_inc_return(&dev->mkey_var);
void *mkc;

mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
MLX5_SET(mkc, mkc, mkey_7_0, key);
- mkey->key = key;
+ *mkey = key;
}

static int mlx5_ib_create_mkey(struct mlx5_ib_dev *dev,
@@ -104,7 +103,7 @@ static int mlx5_ib_create_mkey(struct mlx5_ib_dev *dev,
{
int ret;

- assign_mkey_variant(dev, mkey, in);
+ assign_mkey_variant(dev, &mkey->key, in);
ret = mlx5_core_create_mkey(dev->mdev, &mkey->key, in, inlen);
if (!ret)
init_waitqueue_head(&mkey->wait);
@@ -113,8 +112,7 @@ static int mlx5_ib_create_mkey(struct mlx5_ib_dev *dev,
}

static int
-mlx5_ib_create_mkey_cb(struct mlx5_ib_dev *dev,
- struct mlx5_ib_mkey *mkey,
+mlx5_ib_create_mkey_cb(struct mlx5_ib_dev *dev, u32 *mkey,
struct mlx5_async_ctx *async_ctx,
u32 *in, int inlen, u32 *out, int outlen,
struct mlx5_async_work *context)
@@ -142,16 +140,16 @@ static int destroy_mkey(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)

static void create_mkey_callback(int status, struct mlx5_async_work *context)
{
- struct mlx5_ib_mr *mr =
- container_of(context, struct mlx5_ib_mr, cb_work);
- struct mlx5_cache_ent *ent = mr->cache_ent;
+ struct mlx5_async_create_mkey *mkey_out =
+ container_of(context, struct mlx5_async_create_mkey, cb_work);
+ struct mlx5_cache_ent *ent = mkey_out->ent;
struct mlx5_ib_dev *dev = ent->dev;
unsigned long flags;
void *xa_ent;

if (status) {
mlx5_ib_warn(dev, "async reg mr failed. status %d\n", status);
- kfree(mr);
+ kfree(mkey_out);
xa_lock_irqsave(&ent->mkeys, flags);
xa_ent = __xa_erase(&ent->mkeys, ent->reserved--);
WARN_ON(xa_ent != NULL);
@@ -162,32 +160,24 @@ static void create_mkey_callback(int status, struct mlx5_async_work *context)
return;
}

- mr->mmkey.type = MLX5_MKEY_MR;
- mr->mmkey.key |= mlx5_idx_to_mkey(
- MLX5_GET(create_mkey_out, mr->out, mkey_index));
- init_waitqueue_head(&mr->mmkey.wait);
-
+ mkey_out->mkey |= mlx5_idx_to_mkey(
+ MLX5_GET(create_mkey_out, mkey_out->out, mkey_index));
WRITE_ONCE(dev->cache.last_add, jiffies);

xa_lock_irqsave(&ent->mkeys, flags);
- xa_ent = __xa_store(&ent->mkeys, ent->stored++, mr, GFP_ATOMIC);
+ xa_ent = __xa_store(&ent->mkeys, ent->stored++,
+ xa_mk_value(mkey_out->mkey), GFP_ATOMIC);
WARN_ON(xa_ent != NULL);
ent->pending--;
ent->total_mrs++;
/* If we are doing fill_to_high_water then keep going. */
queue_adjust_cache_locked(ent);
xa_unlock_irqrestore(&ent->mkeys, flags);
+ kfree(mkey_out);
}

-static struct mlx5_ib_mr *alloc_cache_mr(struct mlx5_cache_ent *ent, void *mkc)
+static void set_cache_mkc(struct mlx5_cache_ent *ent, void *mkc)
{
- struct mlx5_ib_mr *mr;
-
- mr = kzalloc(sizeof(*mr), GFP_KERNEL);
- if (!mr)
- return NULL;
- mr->cache_ent = ent;
-
set_mkc_access_pd_addr_fields(mkc, 0, 0, ent->dev->umrc.pd);
MLX5_SET(mkc, mkc, free, 1);
MLX5_SET(mkc, mkc, umr_en, 1);
@@ -196,7 +186,7 @@ static struct mlx5_ib_mr *alloc_cache_mr(struct mlx5_cache_ent *ent, void *mkc)

MLX5_SET(mkc, mkc, translations_octword_size, ent->xlt);
MLX5_SET(mkc, mkc, log_page_size, ent->page);
- return mr;
+ return;
}

static int _push_reserve_mkey(struct mlx5_cache_ent *ent)
@@ -222,7 +212,7 @@ static int _push_reserve_mkey(struct mlx5_cache_ent *ent)
static int add_keys(struct mlx5_cache_ent *ent, unsigned int num)
{
size_t inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
- struct mlx5_ib_mr *mr;
+ struct mlx5_async_create_mkey *async_out;
void *mkc;
u32 *in;
int err = 0;
@@ -233,32 +223,37 @@ static int add_keys(struct mlx5_cache_ent *ent, unsigned int num)
return -ENOMEM;

mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+ set_cache_mkc(ent, mkc);
for (i = 0; i < num; i++) {
- mr = alloc_cache_mr(ent, mkc);
- if (!mr) {
+ async_out = kzalloc(sizeof(struct mlx5_async_create_mkey),
+ GFP_KERNEL);
+ if (!async_out) {
err = -ENOMEM;
break;
}
+ async_out->ent = ent;
+
xa_lock_irq(&ent->mkeys);
if (ent->pending >= MAX_PENDING_REG_MR) {
xa_unlock_irq(&ent->mkeys);
err = -EAGAIN;
- kfree(mr);
+ kfree(async_out);
break;
}

err = _push_reserve_mkey(ent);
if (err) {
xa_unlock_irq(&ent->mkeys);
- kfree(mr);
+ kfree(async_out);
break;
}
ent->pending++;
xa_unlock_irq(&ent->mkeys);
- err = mlx5_ib_create_mkey_cb(ent->dev, &mr->mmkey,
+ err = mlx5_ib_create_mkey_cb(ent->dev, &async_out->mkey,
&ent->dev->async_ctx, in, inlen,
- mr->out, sizeof(mr->out),
- &mr->cb_work);
+ async_out->out,
+ sizeof(async_out->out),
+ &async_out->cb_work);
if (err) {
xa_lock_irq(&ent->mkeys);
WARN_ON(__xa_erase(&ent->mkeys, ent->reserved--) !=
@@ -266,7 +261,7 @@ static int add_keys(struct mlx5_cache_ent *ent, unsigned int num)
ent->pending--;
xa_unlock_irq(&ent->mkeys);
mlx5_ib_warn(ent->dev, "create mkey failed %d\n", err);
- kfree(mr);
+ kfree(async_out);
break;
}
}
@@ -276,57 +271,44 @@ static int add_keys(struct mlx5_cache_ent *ent, unsigned int num)
}

/* Synchronously create a MR in the cache */
-static struct mlx5_ib_mr *create_cache_mr(struct mlx5_cache_ent *ent)
+static int create_cache_mkey(struct mlx5_cache_ent *ent, u32 *mkey)
{
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);
+ return -ENOMEM;
mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+ set_cache_mkc(ent, mkc);

- mr = alloc_cache_mr(ent, mkc);
- if (!mr) {
- err = -ENOMEM;
- goto free_in;
- }
-
- err = mlx5_core_create_mkey(ent->dev->mdev, &mr->mmkey.key, in, inlen);
+ err = mlx5_core_create_mkey(ent->dev->mdev, mkey, in, inlen);
if (err)
- goto free_mr;
+ goto free_in;

- init_waitqueue_head(&mr->mmkey.wait);
- mr->mmkey.type = MLX5_MKEY_MR;
WRITE_ONCE(ent->dev->cache.last_add, jiffies);
xa_lock_irq(&ent->mkeys);
ent->total_mrs++;
xa_unlock_irq(&ent->mkeys);
- kfree(in);
- return mr;
-free_mr:
- kfree(mr);
free_in:
kfree(in);
- return ERR_PTR(err);
+ return err;
}

static void remove_cache_mr_locked(struct mlx5_cache_ent *ent)
{
- struct mlx5_ib_mr *mr;
+ void *xa_ent;

if (!ent->stored)
return;
- mr = __xa_store(&ent->mkeys, --ent->stored, NULL, GFP_KERNEL);
- WARN_ON(mr == NULL || xa_is_err(mr));
+ xa_ent = __xa_store(&ent->mkeys, --ent->stored, NULL, GFP_KERNEL);
+ WARN_ON(xa_ent == NULL || xa_is_err(xa_ent));
WARN_ON(__xa_erase(&ent->mkeys, --ent->reserved) != NULL);
ent->total_mrs--;
xa_unlock_irq(&ent->mkeys);
- mlx5_core_destroy_mkey(ent->dev->mdev, mr->mmkey.key);
- kfree(mr);
+ mlx5_core_destroy_mkey(ent->dev->mdev, (u32)xa_to_value(xa_ent));
xa_lock_irq(&ent->mkeys);
}

@@ -598,11 +580,16 @@ struct mlx5_ib_mr *mlx5_mr_cache_alloc(struct mlx5_ib_dev *dev,
int access_flags)
{
struct mlx5_ib_mr *mr;
+ void *xa_ent;
+ int err;

- /* Matches access in alloc_cache_mr() */
if (!mlx5_ib_can_reconfig_with_umr(dev, 0, access_flags))
return ERR_PTR(-EOPNOTSUPP);

+ mr = kzalloc(sizeof(*mr), GFP_KERNEL);
+ if (!mr)
+ return ERR_PTR(-ENOMEM);
+
xa_lock_irq(&ent->mkeys);
if (!ent->stored) {
if (ent->limit) {
@@ -610,9 +597,11 @@ struct mlx5_ib_mr *mlx5_mr_cache_alloc(struct mlx5_ib_dev *dev,
ent->miss++;
}
xa_unlock_irq(&ent->mkeys);
- mr = create_cache_mr(ent);
- if (IS_ERR(mr))
- return mr;
+ err = create_cache_mkey(ent, &mr->mmkey.key);
+ if (err) {
+ kfree(mr);
+ return ERR_PTR(err);
+ }
} else {
mr = __xa_store(&ent->mkeys, --ent->stored, NULL,
GFP_KERNEL);
@@ -621,9 +610,13 @@ struct mlx5_ib_mr *mlx5_mr_cache_alloc(struct mlx5_ib_dev *dev,
queue_adjust_cache_locked(ent);
xa_unlock_irq(&ent->mkeys);

- mlx5_clear_mr(mr);
+ mr->mmkey.key = (u32)xa_to_value(xa_ent);
}
+ mr->cache_ent = ent;
+ mr->mmkey.type = MLX5_MKEY_MR;
+ init_waitqueue_head(&mr->mmkey.wait);
return mr;
+
}

static void mlx5_mr_cache_free(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
@@ -631,7 +624,8 @@ static void mlx5_mr_cache_free(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
struct mlx5_cache_ent *ent = mr->cache_ent;

xa_lock_irq(&ent->mkeys);
- WARN_ON(__xa_store(&ent->mkeys, ent->stored++, mr, 0) != NULL);
+ WARN_ON(__xa_store(&ent->mkeys, ent->stored++,
+ xa_mk_value(mr->mmkey.key), 0) != NULL);
queue_adjust_cache_locked(ent);
xa_unlock_irq(&ent->mkeys);
}
@@ -640,17 +634,16 @@ static void clean_keys(struct mlx5_ib_dev *dev, int c)
{
struct mlx5_mr_cache *cache = &dev->cache;
struct mlx5_cache_ent *ent = &cache->ent[c];
- struct mlx5_ib_mr *mr;
unsigned long index;
+ void *entry;

cancel_delayed_work(&ent->dwork);
- xa_for_each(&ent->mkeys, index, mr) {
+ xa_for_each(&ent->mkeys, index, entry) {
xa_lock_irq(&ent->mkeys);
__xa_erase(&ent->mkeys, index);
ent->total_mrs--;
xa_unlock_irq(&ent->mkeys);
- mlx5_core_destroy_mkey(dev->mdev, mr->mmkey.key);
- kfree(mr);
+ mlx5_core_destroy_mkey(dev->mdev, (u32)xa_to_value(entry));
}
}

@@ -1982,12 +1975,12 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
mlx5_ib_free_odp_mr(mr);
}

- if (mr->cache_ent) {
+ if (mr->cache_ent)
mlx5_mr_cache_free(dev, mr);
- } else {
+ else
mlx5_free_priv_descs(mr);
- kfree(mr);
- }
+
+ kfree(mr);
return 0;
}

--
2.33.1