[dpdk-dev] [PATCH] common/mlx5: share memory free callback

[dpdk-dev] [PATCH] common/mlx5: share memory free callback

[Michael Baum]

All the mlx5 drivers using MRs for data-path must unregister the mapped
memory when it is freed by the dpdk process.

Currently, only the net/eth driver unregisters MRs in free event.

Move the net callback handler from net driver to common.

Cc: stable@dpdk.org

Signed-off-by: Michael Baum <michaelba@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>
---
 drivers/common/mlx5/mlx5_common_mr.c | 89 +++++++++++++++++++++++++++
 drivers/common/mlx5/mlx5_common_mr.h |  3 +
 drivers/common/mlx5/version.map      |  1 +
 drivers/net/mlx5/mlx5_mr.c           | 90 +---------------------------
 4 files changed, 95 insertions(+), 88 deletions(-)

diff --git a/drivers/common/mlx5/mlx5_common_mr.c b/drivers/common/mlx5/mlx5_common_mr.c
index afb5b3d0a7..98fe8698e2 100644
--- a/drivers/common/mlx5/mlx5_common_mr.c
+++ b/drivers/common/mlx5/mlx5_common_mr.c
@@ -1062,6 +1062,95 @@ mlx5_create_mr_ext(void *pd, uintptr_t addr, size_t len, int socket_id,
 	return mr;
 }
 
+/**
+ * Callback for memory free event. Iterate freed memsegs and check whether it
+ * belongs to an existing MR. If found, clear the bit from bitmap of MR. As a
+ * result, the MR would be fragmented. If it becomes empty, the MR will be freed
+ * later by mlx5_mr_garbage_collect(). Even if this callback is called from a
+ * secondary process, the garbage collector will be called in primary process
+ * as the secondary process can't call mlx5_mr_create().
+ *
+ * The global cache must be rebuilt if there's any change and this event has to
+ * be propagated to dataplane threads to flush the local caches.
+ *
+ * @param share_cache
+ *   Pointer to a global shared MR cache.
+ * @param ibdev_name
+ *   Name of ibv device.
+ * @param addr
+ *   Address of freed memory.
+ * @param len
+ *   Size of freed memory.
+ */
+void
+mlx5_free_mr_by_addr(struct mlx5_mr_share_cache *share_cache,
+		     const char *ibdev_name, const void *addr, size_t len)
+{
+	const struct rte_memseg_list *msl;
+	struct mlx5_mr *mr;
+	int ms_n;
+	int i;
+	int rebuild = 0;
+
+	DRV_LOG(DEBUG, "device %s free callback: addr=%p, len=%zu",
+		ibdev_name, addr, len);
+	msl = rte_mem_virt2memseg_list(addr);
+	/* addr and len must be page-aligned. */
+	MLX5_ASSERT((uintptr_t)addr ==
+		    RTE_ALIGN((uintptr_t)addr, msl->page_sz));
+	MLX5_ASSERT(len == RTE_ALIGN(len, msl->page_sz));
+	ms_n = len / msl->page_sz;
+	rte_rwlock_write_lock(&share_cache->rwlock);
+	/* Clear bits of freed memsegs from MR. */
+	for (i = 0; i < ms_n; ++i) {
+		const struct rte_memseg *ms;
+		struct mr_cache_entry entry;
+		uintptr_t start;
+		int ms_idx;
+		uint32_t pos;
+
+		/* Find MR having this memseg. */
+		start = (uintptr_t)addr + i * msl->page_sz;
+		mr = mlx5_mr_lookup_list(share_cache, &entry, start);
+		if (mr == NULL)
+			continue;
+		MLX5_ASSERT(mr->msl); /* Can't be external memory. */
+		ms = rte_mem_virt2memseg((void *)start, msl);
+		MLX5_ASSERT(ms != NULL);
+		MLX5_ASSERT(msl->page_sz == ms->hugepage_sz);
+		ms_idx = rte_fbarray_find_idx(&msl->memseg_arr, ms);
+		pos = ms_idx - mr->ms_base_idx;
+		MLX5_ASSERT(rte_bitmap_get(mr->ms_bmp, pos));
+		MLX5_ASSERT(pos < mr->ms_bmp_n);
+		DRV_LOG(DEBUG, "device %s MR(%p): clear bitmap[%u] for addr %p",
+			ibdev_name, (void *)mr, pos, (void *)start);
+		rte_bitmap_clear(mr->ms_bmp, pos);
+		if (--mr->ms_n == 0) {
+			LIST_REMOVE(mr, mr);
+			LIST_INSERT_HEAD(&share_cache->mr_free_list, mr, mr);
+			DRV_LOG(DEBUG, "device %s remove MR(%p) from list",
+				ibdev_name, (void *)mr);
+		}
+		/*
+		 * MR is fragmented or will be freed. the global cache must be
+		 * rebuilt.
+		 */
+		rebuild = 1;
+	}
+	if (rebuild) {
+		mlx5_mr_rebuild_cache(share_cache);
+		/*
+		 * No explicit wmb is needed after updating dev_gen due to
+		 * store-release ordering in unlock that provides the
+		 * implicit barrier at the software visible level.
+		 */
+		++share_cache->dev_gen;
+		DRV_LOG(DEBUG, "broadcasting local cache flush, gen=%d",
+			share_cache->dev_gen);
+	}
+	rte_rwlock_write_unlock(&share_cache->rwlock);
+}
+
 /**
  * Dump all the created MRs and the global cache entries.
  *
diff --git a/drivers/common/mlx5/mlx5_common_mr.h b/drivers/common/mlx5/mlx5_common_mr.h
index 5cc3f097c2..6e465a05e9 100644
--- a/drivers/common/mlx5/mlx5_common_mr.h
+++ b/drivers/common/mlx5/mlx5_common_mr.h
@@ -144,6 +144,9 @@ void mlx5_mr_rebuild_cache(struct mlx5_mr_share_cache *share_cache);
 __rte_internal
 void mlx5_mr_flush_local_cache(struct mlx5_mr_ctrl *mr_ctrl);
 __rte_internal
+void mlx5_free_mr_by_addr(struct mlx5_mr_share_cache *share_cache,
+			  const char *ibdev_name, const void *addr, size_t len);
+__rte_internal
 int
 mlx5_mr_insert_cache(struct mlx5_mr_share_cache *share_cache,
 		     struct mlx5_mr *mr);
diff --git a/drivers/common/mlx5/version.map b/drivers/common/mlx5/version.map
index db4f13f1f7..b8be73a77b 100644
--- a/drivers/common/mlx5/version.map
+++ b/drivers/common/mlx5/version.map
@@ -103,6 +103,7 @@ INTERNAL {
 	mlx5_mr_insert_cache;
 	mlx5_mr_lookup_cache;
 	mlx5_mr_lookup_list;
+	mlx5_free_mr_by_addr;
 	mlx5_mr_rebuild_cache;
 	mlx5_mr_release_cache;
 
diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
index 0c5403e493..0b6cfc8cb9 100644
--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c
@@ -31,93 +31,6 @@ struct mr_update_mp_data {
 	int ret;
 };
 
-/**
- * Callback for memory free event. Iterate freed memsegs and check whether it
- * belongs to an existing MR. If found, clear the bit from bitmap of MR. As a
- * result, the MR would be fragmented. If it becomes empty, the MR will be freed
- * later by mlx5_mr_garbage_collect(). Even if this callback is called from a
- * secondary process, the garbage collector will be called in primary process
- * as the secondary process can't call mlx5_mr_create().
- *
- * The global cache must be rebuilt if there's any change and this event has to
- * be propagated to dataplane threads to flush the local caches.
- *
- * @param sh
- *   Pointer to the Ethernet device shared context.
- * @param addr
- *   Address of freed memory.
- * @param len
- *   Size of freed memory.
- */
-static void
-mlx5_mr_mem_event_free_cb(struct mlx5_dev_ctx_shared *sh,
-			  const void *addr, size_t len)
-{
-	const struct rte_memseg_list *msl;
-	struct mlx5_mr *mr;
-	int ms_n;
-	int i;
-	int rebuild = 0;
-
-	DRV_LOG(DEBUG, "device %s free callback: addr=%p, len=%zu",
-	      sh->ibdev_name, addr, len);
-	msl = rte_mem_virt2memseg_list(addr);
-	/* addr and len must be page-aligned. */
-	MLX5_ASSERT((uintptr_t)addr ==
-		    RTE_ALIGN((uintptr_t)addr, msl->page_sz));
-	MLX5_ASSERT(len == RTE_ALIGN(len, msl->page_sz));
-	ms_n = len / msl->page_sz;
-	rte_rwlock_write_lock(&sh->share_cache.rwlock);
-	/* Clear bits of freed memsegs from MR. */
-	for (i = 0; i < ms_n; ++i) {
-		const struct rte_memseg *ms;
-		struct mr_cache_entry entry;
-		uintptr_t start;
-		int ms_idx;
-		uint32_t pos;
-
-		/* Find MR having this memseg. */
-		start = (uintptr_t)addr + i * msl->page_sz;
-		mr = mlx5_mr_lookup_list(&sh->share_cache, &entry, start);
-		if (mr == NULL)
-			continue;
-		MLX5_ASSERT(mr->msl); /* Can't be external memory. */
-		ms = rte_mem_virt2memseg((void *)start, msl);
-		MLX5_ASSERT(ms != NULL);
-		MLX5_ASSERT(msl->page_sz == ms->hugepage_sz);
-		ms_idx = rte_fbarray_find_idx(&msl->memseg_arr, ms);
-		pos = ms_idx - mr->ms_base_idx;
-		MLX5_ASSERT(rte_bitmap_get(mr->ms_bmp, pos));
-		MLX5_ASSERT(pos < mr->ms_bmp_n);
-		DRV_LOG(DEBUG, "device %s MR(%p): clear bitmap[%u] for addr %p",
-		      sh->ibdev_name, (void *)mr, pos, (void *)start);
-		rte_bitmap_clear(mr->ms_bmp, pos);
-		if (--mr->ms_n == 0) {
-			LIST_REMOVE(mr, mr);
-			LIST_INSERT_HEAD(&sh->share_cache.mr_free_list, mr, mr);
-			DRV_LOG(DEBUG, "device %s remove MR(%p) from list",
-			      sh->ibdev_name, (void *)mr);
-		}
-		/*
-		 * MR is fragmented or will be freed. the global cache must be
-		 * rebuilt.
-		 */
-		rebuild = 1;
-	}
-	if (rebuild) {
-		mlx5_mr_rebuild_cache(&sh->share_cache);
-		/*
-		 * No explicit wmb is needed after updating dev_gen due to
-		 * store-release ordering in unlock that provides the
-		 * implicit barrier at the software visible level.
-		 */
-		++sh->share_cache.dev_gen;
-		DRV_LOG(DEBUG, "broadcasting local cache flush, gen=%d",
-		      sh->share_cache.dev_gen);
-	}
-	rte_rwlock_write_unlock(&sh->share_cache.rwlock);
-}
-
 /**
  * Callback for memory event. This can be called from both primary and secondary
  * process.
@@ -143,7 +56,8 @@ mlx5_mr_mem_event_cb(enum rte_mem_event event_type, const void *addr,
 		rte_rwlock_write_lock(&mlx5_shared_data->mem_event_rwlock);
 		/* Iterate all the existing mlx5 devices. */
 		LIST_FOREACH(sh, dev_list, mem_event_cb)
-			mlx5_mr_mem_event_free_cb(sh, addr, len);
+			mlx5_free_mr_by_addr(&sh->share_cache,
+					     sh->ibdev_name, addr, len);
 		rte_rwlock_write_unlock(&mlx5_shared_data->mem_event_rwlock);
 		break;
 	case RTE_MEM_EVENT_ALLOC:
-- 
2.25.1

Re: [dpdk-dev] [PATCH] common/mlx5: share memory free callback

[Raslan Darawsheh]

Hi,

> -----Original Message-----
> From: Michael Baum <michaelba@nvidia.com>
> Sent: Monday, June 28, 2021 6:06 PM
> To: dev@dpdk.org
> Cc: Matan Azrad <matan@nvidia.com>; Raslan Darawsheh
> <rasland@nvidia.com>; Slava Ovsiienko <viacheslavo@nvidia.com>;
> stable@dpdk.org
> Subject: [PATCH] common/mlx5: share memory free callback
> 
> All the mlx5 drivers using MRs for data-path must unregister the mapped
> memory when it is freed by the dpdk process.
> 
> Currently, only the net/eth driver unregisters MRs in free event.
> 
> Move the net callback handler from net driver to common.
> 
> Cc: stable@dpdk.org
> 
> Signed-off-by: Michael Baum <michaelba@nvidia.com>
> Acked-by: Matan Azrad <matan@nvidia.com>
> ---

Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh