[PATCH net-next v2 00/15] net: page_pool: add netlink-based introspection

[PATCH net-next v2 00/15] net: page_pool: add netlink-based introspection

[Jakub Kicinski]

We recently started to deploy newer kernels / drivers at Meta,
making significant use of page pools for the first time.
We immediately run into page pool leaks both real and false positive
warnings. As Eric pointed out/predicted there's no guarantee that
applications will read / close their sockets so a page pool page
may be stuck in a socket (but not leaked) forever. This happens
a lot in our fleet. Most of these are obviously due to application
bugs but we should not be printing kernel warnings due to minor
application resource leaks.

Conversely the page pool memory may get leaked at runtime, and
we have no way to detect / track that, unless someone reconfigures
the NIC and destroys the page pools which leaked the pages.

The solution presented here is to expose the memory use of page
pools via netlink. This allows for continuous monitoring of memory
used by page pools, regardless if they were destroyed or not.
Sample in patch 15 can print the memory use and recycling
efficiency:

$ ./page-pool
    eth0[2]	page pools: 10 (zombies: 0)
		refs: 41984 bytes: 171966464 (refs: 0 bytes: 0)
		recycling: 90.3% (alloc: 656:397681 recycle: 89652:270201)

v2:
 - hopefully fix build with PAGE_POOL=n
v1:  https://lore.kernel.org/all/20231024160220.3973311-1-kuba@kernel.org/
 - The main change compared to the RFC is that the API now exposes
   outstanding references and byte counts even for "live" page pools.
   The warning is no longer printed if page pool is accessible via netlink.
RFC: https://lore.kernel.org/all/20230816234303.3786178-1-kuba@kernel.org/

Jakub Kicinski (15):
  net: page_pool: split the page_pool_params into fast and slow
  net: page_pool: avoid touching slow on the fastpath
  net: page_pool: factor out uninit
  net: page_pool: id the page pools
  net: page_pool: record pools per netdev
  net: page_pool: stash the NAPI ID for easier access
  eth: link netdev to page_pools in drivers
  net: page_pool: add nlspec for basic access to page pools
  net: page_pool: implement GET in the netlink API
  net: page_pool: add netlink notifications for state changes
  net: page_pool: report amount of memory held by page pools
  net: page_pool: report when page pool was destroyed
  net: page_pool: expose page pool stats via netlink
  net: page_pool: mute the periodic warning for visible page pools
  tools: ynl: add sample for getting page-pool information

 Documentation/netlink/specs/netdev.yaml       | 166 +++++++
 Documentation/networking/page_pool.rst        |  10 +-
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     |   1 +
 .../net/ethernet/mellanox/mlx5/core/en_main.c |   1 +
 drivers/net/ethernet/microsoft/mana/mana_en.c |   1 +
 drivers/net/ethernet/socionext/netsec.c       |   2 +
 include/linux/list.h                          |  20 +
 include/linux/netdevice.h                     |   4 +
 include/linux/poison.h                        |   2 +
 include/net/page_pool/helpers.h               |   8 +-
 include/net/page_pool/types.h                 |  43 +-
 include/uapi/linux/netdev.h                   |  36 ++
 net/core/Makefile                             |   2 +-
 net/core/netdev-genl-gen.c                    |  60 +++
 net/core/netdev-genl-gen.h                    |  11 +
 net/core/page_pool.c                          |  78 ++--
 net/core/page_pool_priv.h                     |  12 +
 net/core/page_pool_user.c                     | 414 +++++++++++++++++
 tools/include/uapi/linux/netdev.h             |  36 ++
 tools/net/ynl/generated/netdev-user.c         | 419 ++++++++++++++++++
 tools/net/ynl/generated/netdev-user.h         | 171 +++++++
 tools/net/ynl/lib/ynl.h                       |   2 +-
 tools/net/ynl/samples/.gitignore              |   1 +
 tools/net/ynl/samples/Makefile                |   2 +-
 tools/net/ynl/samples/page-pool.c             | 147 ++++++
 25 files changed, 1601 insertions(+), 48 deletions(-)
 create mode 100644 net/core/page_pool_priv.h
 create mode 100644 net/core/page_pool_user.c
 create mode 100644 tools/net/ynl/samples/page-pool.c

-- 
2.42.0

[PATCH net-next v2 01/15] net: page_pool: split the page_pool_params into fast and slow

[Jakub Kicinski]

struct page_pool is rather performance critical and we use
16B of the first cache line to store 2 pointers used only
by test code. Future patches will add more informational
(non-fast path) attributes.

It's convenient for the user of the API to not have to worry
which fields are fast and which are slow path. Use struct
groups to split the params into the two categories internally.

Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/net/page_pool/types.h | 31 +++++++++++++++++++------------
 net/core/page_pool.c          |  7 ++++---
 2 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 6fc5134095ed..23950fcc4eca 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -54,18 +54,22 @@ struct pp_alloc_cache {
  * @offset:	DMA sync address offset for PP_FLAG_DMA_SYNC_DEV
  */
 struct page_pool_params {
-	unsigned int	flags;
-	unsigned int	order;
-	unsigned int	pool_size;
-	int		nid;
-	struct device	*dev;
-	struct napi_struct *napi;
-	enum dma_data_direction dma_dir;
-	unsigned int	max_len;
-	unsigned int	offset;
+	struct_group_tagged(page_pool_params_fast, fast,
+		unsigned int	flags;
+		unsigned int	order;
+		unsigned int	pool_size;
+		int		nid;
+		struct device	*dev;
+		struct napi_struct *napi;
+		enum dma_data_direction dma_dir;
+		unsigned int	max_len;
+		unsigned int	offset;
+	);
+	struct_group_tagged(page_pool_params_slow, slow,
 /* private: used by test code only */
-	void (*init_callback)(struct page *page, void *arg);
-	void *init_arg;
+		void (*init_callback)(struct page *page, void *arg);
+		void *init_arg;
+	);
 };
 
 #ifdef CONFIG_PAGE_POOL_STATS
@@ -119,7 +123,7 @@ struct page_pool_stats {
 #endif
 
 struct page_pool {
-	struct page_pool_params p;
+	struct page_pool_params_fast p;
 
 	long frag_users;
 	struct page *frag_page;
@@ -178,6 +182,9 @@ struct page_pool {
 	refcount_t user_cnt;
 
 	u64 destroy_cnt;
+
+	/* Slow/Control-path information follows */
+	struct page_pool_params_slow slow;
 };
 
 struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index dec544337236..ab22a2fdae57 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -173,7 +173,8 @@ static int page_pool_init(struct page_pool *pool,
 {
 	unsigned int ring_qsize = 1024; /* Default */
 
-	memcpy(&pool->p, params, sizeof(pool->p));
+	memcpy(&pool->p, &params->fast, sizeof(pool->p));
+	memcpy(&pool->slow, &params->slow, sizeof(pool->slow));
 
 	/* Validate only known flags were used */
 	if (pool->p.flags & ~(PP_FLAG_ALL))
@@ -388,8 +389,8 @@ static void page_pool_set_pp_info(struct page_pool *pool,
 	 * the overhead is negligible.
 	 */
 	page_pool_fragment_page(page, 1);
-	if (pool->p.init_callback)
-		pool->p.init_callback(page, pool->p.init_arg);
+	if (pool->slow.init_callback)
+		pool->slow.init_callback(page, pool->slow.init_arg);
 }
 
 static void page_pool_clear_pp_info(struct page *page)
-- 
2.42.0

[PATCH net-next v2 02/15] net: page_pool: avoid touching slow on the fastpath

[Jakub Kicinski]

To fully benefit from previous commit add one byte of state
in the first cache line recording if we need to look at
the slow part.

The packing isn't all that impressive right now, we create
a 7B hole. I'm expecting Olek's rework will reshuffle this,
anyway.

Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/net/page_pool/types.h | 2 ++
 net/core/page_pool.c          | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 23950fcc4eca..e1bb92c192de 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -125,6 +125,8 @@ struct page_pool_stats {
 struct page_pool {
 	struct page_pool_params_fast p;
 
+	bool has_init_callback;
+
 	long frag_users;
 	struct page *frag_page;
 	unsigned int frag_offset;
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index ab22a2fdae57..df2a06d7da52 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -212,6 +212,8 @@ static int page_pool_init(struct page_pool *pool,
 		 */
 	}
 
+	pool->has_init_callback = !!pool->slow.init_callback;
+
 #ifdef CONFIG_PAGE_POOL_STATS
 	pool->recycle_stats = alloc_percpu(struct page_pool_recycle_stats);
 	if (!pool->recycle_stats)
@@ -389,7 +391,7 @@ static void page_pool_set_pp_info(struct page_pool *pool,
 	 * the overhead is negligible.
 	 */
 	page_pool_fragment_page(page, 1);
-	if (pool->slow.init_callback)
+	if (pool->has_init_callback)
 		pool->slow.init_callback(page, pool->slow.init_arg);
 }
 
-- 
2.42.0

[PATCH net-next v2 03/15] net: page_pool: factor out uninit

[Jakub Kicinski]

We'll soon (next change in the series) need a fuller unwind path
in page_pool_create() so create the inverse of page_pool_init().

Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/core/page_pool.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index df2a06d7da52..2e4575477e71 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -238,6 +238,18 @@ static int page_pool_init(struct page_pool *pool,
 	return 0;
 }
 
+static void page_pool_uninit(struct page_pool *pool)
+{
+	ptr_ring_cleanup(&pool->ring, NULL);
+
+	if (pool->p.flags & PP_FLAG_DMA_MAP)
+		put_device(pool->p.dev);
+
+#ifdef CONFIG_PAGE_POOL_STATS
+	free_percpu(pool->recycle_stats);
+#endif
+}
+
 /**
  * page_pool_create() - create a page pool.
  * @params: parameters, see struct page_pool_params
@@ -821,14 +833,7 @@ static void __page_pool_destroy(struct page_pool *pool)
 	if (pool->disconnect)
 		pool->disconnect(pool);
 
-	ptr_ring_cleanup(&pool->ring, NULL);
-
-	if (pool->p.flags & PP_FLAG_DMA_MAP)
-		put_device(pool->p.dev);
-
-#ifdef CONFIG_PAGE_POOL_STATS
-	free_percpu(pool->recycle_stats);
-#endif
+	page_pool_uninit(pool);
 	kfree(pool);
 }
 
-- 
2.42.0

[PATCH net-next v2 04/15] net: page_pool: id the page pools

[Jakub Kicinski]

To give ourselves the flexibility of creating netlink commands
and ability to refer to page pool instances in uAPIs create
IDs for page pools.

Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/net/page_pool/types.h |  4 ++++
 net/core/Makefile             |  2 +-
 net/core/page_pool.c          | 21 +++++++++++++++-----
 net/core/page_pool_priv.h     |  9 +++++++++
 net/core/page_pool_user.c     | 36 +++++++++++++++++++++++++++++++++++
 5 files changed, 66 insertions(+), 6 deletions(-)
 create mode 100644 net/core/page_pool_priv.h
 create mode 100644 net/core/page_pool_user.c

diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index e1bb92c192de..c19f0df3bf0b 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -187,6 +187,10 @@ struct page_pool {
 
 	/* Slow/Control-path information follows */
 	struct page_pool_params_slow slow;
+	/* User-facing fields, protected by page_pools_lock */
+	struct {
+		u32 id;
+	} user;
 };
 
 struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);
diff --git a/net/core/Makefile b/net/core/Makefile
index 0cb734cbc24b..821aec06abf1 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -18,7 +18,7 @@ obj-y		     += dev.o dev_addr_lists.o dst.o netevent.o \
 obj-$(CONFIG_NETDEV_ADDR_LIST_TEST) += dev_addr_lists_test.o
 
 obj-y += net-sysfs.o
-obj-$(CONFIG_PAGE_POOL) += page_pool.o
+obj-$(CONFIG_PAGE_POOL) += page_pool.o page_pool_user.o
 obj-$(CONFIG_PROC_FS) += net-procfs.o
 obj-$(CONFIG_NET_PKTGEN) += pktgen.o
 obj-$(CONFIG_NETPOLL) += netpoll.o
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 2e4575477e71..a8d96ea38d18 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -23,6 +23,8 @@
 
 #include <trace/events/page_pool.h>
 
+#include "page_pool_priv.h"
+
 #define DEFER_TIME (msecs_to_jiffies(1000))
 #define DEFER_WARN_INTERVAL (60 * HZ)
 
@@ -264,13 +266,21 @@ struct page_pool *page_pool_create(const struct page_pool_params *params)
 		return ERR_PTR(-ENOMEM);
 
 	err = page_pool_init(pool, params);
-	if (err < 0) {
-		pr_warn("%s() gave up with errno %d\n", __func__, err);
-		kfree(pool);
-		return ERR_PTR(err);
-	}
+	if (err < 0)
+		goto err_free;
+
+	err = page_pool_list(pool);
+	if (err)
+		goto err_uninit;
 
 	return pool;
+
+err_uninit:
+	page_pool_uninit(pool);
+err_free:
+	pr_warn("%s() gave up with errno %d\n", __func__, err);
+	kfree(pool);
+	return ERR_PTR(err);
 }
 EXPORT_SYMBOL(page_pool_create);
 
@@ -833,6 +843,7 @@ static void __page_pool_destroy(struct page_pool *pool)
 	if (pool->disconnect)
 		pool->disconnect(pool);
 
+	page_pool_unlist(pool);
 	page_pool_uninit(pool);
 	kfree(pool);
 }
diff --git a/net/core/page_pool_priv.h b/net/core/page_pool_priv.h
new file mode 100644
index 000000000000..c17ea092b4ab
--- /dev/null
+++ b/net/core/page_pool_priv.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __PAGE_POOL_PRIV_H
+#define __PAGE_POOL_PRIV_H
+
+int page_pool_list(struct page_pool *pool);
+void page_pool_unlist(struct page_pool *pool);
+
+#endif
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
new file mode 100644
index 000000000000..630d1eeecf2a
--- /dev/null
+++ b/net/core/page_pool_user.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/mutex.h>
+#include <linux/xarray.h>
+#include <net/page_pool/types.h>
+
+#include "page_pool_priv.h"
+
+static DEFINE_XARRAY_FLAGS(page_pools, XA_FLAGS_ALLOC1);
+static DEFINE_MUTEX(page_pools_lock);
+
+int page_pool_list(struct page_pool *pool)
+{
+	static u32 id_alloc_next;
+	int err;
+
+	mutex_lock(&page_pools_lock);
+	err = xa_alloc_cyclic(&page_pools, &pool->user.id, pool, xa_limit_32b,
+			      &id_alloc_next, GFP_KERNEL);
+	if (err < 0)
+		goto err_unlock;
+
+	mutex_unlock(&page_pools_lock);
+	return 0;
+
+err_unlock:
+	mutex_unlock(&page_pools_lock);
+	return err;
+}
+
+void page_pool_unlist(struct page_pool *pool)
+{
+	mutex_lock(&page_pools_lock);
+	xa_erase(&page_pools, pool->user.id);
+	mutex_unlock(&page_pools_lock);
+}
-- 
2.42.0

[PATCH net-next v2 05/15] net: page_pool: record pools per netdev

[Jakub Kicinski]

Link the page pools with netdevs. This needs to be netns compatible
so we have two options. Either we record the pools per netns and
have to worry about moving them as the netdev gets moved.
Or we record them directly on the netdev so they move with the netdev
without any extra work.

Implement the latter option. Since pools may outlast netdev we need
a place to store orphans. In time honored tradition use loopback
for this purpose.

Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
v1: fix race between page pool and netdev disappearing (Simon)
---
 include/linux/list.h          | 20 ++++++++
 include/linux/netdevice.h     |  4 ++
 include/linux/poison.h        |  2 +
 include/net/page_pool/types.h |  4 ++
 net/core/page_pool_user.c     | 90 +++++++++++++++++++++++++++++++++++
 5 files changed, 120 insertions(+)

diff --git a/include/linux/list.h b/include/linux/list.h
index 1837caedf723..059aa1fff41e 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -1119,6 +1119,26 @@ static inline void hlist_move_list(struct hlist_head *old,
 	old->first = NULL;
 }
 
+/**
+ * hlist_splice_init() - move all entries from one list to another
+ * @from: hlist_head from which entries will be moved
+ * @last: last entry on the @from list
+ * @to:   hlist_head to which entries will be moved
+ *
+ * @to can be empty, @from must contain at least @last.
+ */
+static inline void hlist_splice_init(struct hlist_head *from,
+				     struct hlist_node *last,
+				     struct hlist_head *to)
+{
+	if (to->first)
+		to->first->pprev = &last->next;
+	last->next = to->first;
+	to->first = from->first;
+	from->first->pprev = &to->first;
+	from->first = NULL;
+}
+
 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
 
 #define hlist_for_each(pos, head) \
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 2d840d7056f2..d6554f308ff1 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2435,6 +2435,10 @@ struct net_device {
 #if IS_ENABLED(CONFIG_DPLL)
 	struct dpll_pin		*dpll_pin;
 #endif
+#if IS_ENABLED(CONFIG_PAGE_POOL)
+	/** @page_pools: page pools created for this netdevice */
+	struct hlist_head	page_pools;
+#endif
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)
 
diff --git a/include/linux/poison.h b/include/linux/poison.h
index 851a855d3868..27a7dad17eef 100644
--- a/include/linux/poison.h
+++ b/include/linux/poison.h
@@ -83,6 +83,8 @@
 
 /********** net/core/skbuff.c **********/
 #define SKB_LIST_POISON_NEXT	((void *)(0x800 + POISON_POINTER_DELTA))
+/********** net/ **********/
+#define NET_PTR_POISON		((void *)(0x801 + POISON_POINTER_DELTA))
 
 /********** kernel/bpf/ **********/
 #define BPF_PTR_POISON ((void *)(0xeB9FUL + POISON_POINTER_DELTA))
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index c19f0df3bf0b..b258a571201e 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -5,6 +5,7 @@
 
 #include <linux/dma-direction.h>
 #include <linux/ptr_ring.h>
+#include <linux/types.h>
 
 #define PP_FLAG_DMA_MAP		BIT(0) /* Should page_pool do the DMA
 					* map/unmap
@@ -48,6 +49,7 @@ struct pp_alloc_cache {
  * @pool_size:	size of the ptr_ring
  * @nid:	NUMA node id to allocate from pages from
  * @dev:	device, for DMA pre-mapping purposes
+ * @netdev:	netdev this pool will serve (leave as NULL if none or multiple)
  * @napi:	NAPI which is the sole consumer of pages, otherwise NULL
  * @dma_dir:	DMA mapping direction
  * @max_len:	max DMA sync memory size for PP_FLAG_DMA_SYNC_DEV
@@ -66,6 +68,7 @@ struct page_pool_params {
 		unsigned int	offset;
 	);
 	struct_group_tagged(page_pool_params_slow, slow,
+		struct net_device *netdev;
 /* private: used by test code only */
 		void (*init_callback)(struct page *page, void *arg);
 		void *init_arg;
@@ -189,6 +192,7 @@ struct page_pool {
 	struct page_pool_params_slow slow;
 	/* User-facing fields, protected by page_pools_lock */
 	struct {
+		struct hlist_node list;
 		u32 id;
 	} user;
 };
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 630d1eeecf2a..1591dbd66d51 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -1,14 +1,31 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/mutex.h>
+#include <linux/netdevice.h>
 #include <linux/xarray.h>
+#include <net/net_debug.h>
 #include <net/page_pool/types.h>
 
 #include "page_pool_priv.h"
 
 static DEFINE_XARRAY_FLAGS(page_pools, XA_FLAGS_ALLOC1);
+/* Protects: page_pools, netdevice->page_pools, pool->slow.netdev, pool->user.
+ * Ordering: inside rtnl_lock
+ */
 static DEFINE_MUTEX(page_pools_lock);
 
+/* Page pools are only reachable from user space (via netlink) if they are
+ * linked to a netdev at creation time. Following page pool "visibility"
+ * states are possible:
+ *  - normal
+ *    - user.list: linked to real netdev, netdev: real netdev
+ *  - orphaned - real netdev has disappeared
+ *    - user.list: linked to lo, netdev: lo
+ *  - invisible - either (a) created without netdev linking, (b) unlisted due
+ *      to error, or (c) the entire namespace which owned this pool disappeared
+ *    - user.list: unhashed, netdev: unknown
+ */
+
 int page_pool_list(struct page_pool *pool)
 {
 	static u32 id_alloc_next;
@@ -20,6 +37,10 @@ int page_pool_list(struct page_pool *pool)
 	if (err < 0)
 		goto err_unlock;
 
+	if (pool->slow.netdev)
+		hlist_add_head(&pool->user.list,
+			       &pool->slow.netdev->page_pools);
+
 	mutex_unlock(&page_pools_lock);
 	return 0;
 
@@ -32,5 +53,74 @@ void page_pool_unlist(struct page_pool *pool)
 {
 	mutex_lock(&page_pools_lock);
 	xa_erase(&page_pools, pool->user.id);
+	hlist_del(&pool->user.list);
 	mutex_unlock(&page_pools_lock);
 }
+
+static void page_pool_unreg_netdev_wipe(struct net_device *netdev)
+{
+	struct page_pool *pool;
+	struct hlist_node *n;
+
+	mutex_lock(&page_pools_lock);
+	hlist_for_each_entry_safe(pool, n, &netdev->page_pools, user.list) {
+		hlist_del_init(&pool->user.list);
+		pool->slow.netdev = NET_PTR_POISON;
+	}
+	mutex_unlock(&page_pools_lock);
+}
+
+static void page_pool_unreg_netdev(struct net_device *netdev)
+{
+	struct page_pool *pool, *last;
+	struct net_device *lo;
+
+	lo = __dev_get_by_index(dev_net(netdev), 1);
+	if (!lo) {
+		netdev_err_once(netdev,
+				"can't get lo to store orphan page pools\n");
+		page_pool_unreg_netdev_wipe(netdev);
+		return;
+	}
+
+	mutex_lock(&page_pools_lock);
+	last = NULL;
+	hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
+		pool->slow.netdev = lo;
+		last = pool;
+	}
+	if (last)
+		hlist_splice_init(&netdev->page_pools, &last->user.list,
+				  &lo->page_pools);
+	mutex_unlock(&page_pools_lock);
+}
+
+static int
+page_pool_netdevice_event(struct notifier_block *nb,
+			  unsigned long event, void *ptr)
+{
+	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+
+	if (event != NETDEV_UNREGISTER)
+		return NOTIFY_DONE;
+
+	if (hlist_empty(&netdev->page_pools))
+		return NOTIFY_OK;
+
+	if (netdev->ifindex != LOOPBACK_IFINDEX)
+		page_pool_unreg_netdev(netdev);
+	else
+		page_pool_unreg_netdev_wipe(netdev);
+	return NOTIFY_OK;
+}
+
+static struct notifier_block page_pool_netdevice_nb = {
+	.notifier_call = page_pool_netdevice_event,
+};
+
+static int __init page_pool_user_init(void)
+{
+	return register_netdevice_notifier(&page_pool_netdevice_nb);
+}
+
+subsys_initcall(page_pool_user_init);
-- 
2.42.0

[PATCH net-next v2 06/15] net: page_pool: stash the NAPI ID for easier access

[Jakub Kicinski]

To avoid any issues with race conditions on accessing napi
and having to think about the lifetime of NAPI objects
in netlink GET - stash the napi_id to which page pool
was linked at creation time.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/net/page_pool/types.h | 1 +
 net/core/page_pool_user.c     | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index b258a571201e..7e47d7bb2c1e 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -193,6 +193,7 @@ struct page_pool {
 	/* User-facing fields, protected by page_pools_lock */
 	struct {
 		struct hlist_node list;
+		u32 napi_id;
 		u32 id;
 	} user;
 };
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 1591dbd66d51..23074d4c75fc 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -37,9 +37,11 @@ int page_pool_list(struct page_pool *pool)
 	if (err < 0)
 		goto err_unlock;
 
-	if (pool->slow.netdev)
+	if (pool->slow.netdev) {
 		hlist_add_head(&pool->user.list,
 			       &pool->slow.netdev->page_pools);
+		pool->user.napi_id = pool->p.napi ? pool->p.napi->napi_id : 0;
+	}
 
 	mutex_unlock(&page_pools_lock);
 	return 0;
-- 
2.42.0

[PATCH net-next v2 07/15] eth: link netdev to page_pools in drivers

[Jakub Kicinski]

Link page pool instances to netdev for the drivers which
already link to NAPI. Unless the driver is doing something
very weird per-NAPI should imply per-netdev.

Add netsec as well, Ilias indicates that it fits the mold.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
v2: add netsec
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c         | 1 +
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 1 +
 drivers/net/ethernet/microsoft/mana/mana_en.c     | 1 +
 drivers/net/ethernet/socionext/netsec.c           | 2 ++
 4 files changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index e6ac1bd21bb3..68cf0036f867 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -3322,6 +3322,7 @@ static int bnxt_alloc_rx_page_pool(struct bnxt *bp,
 		pp.pool_size += bp->rx_ring_size;
 	pp.nid = dev_to_node(&bp->pdev->dev);
 	pp.napi = &rxr->bnapi->napi;
+	pp.netdev = bp->dev;
 	pp.dev = &bp->pdev->dev;
 	pp.dma_dir = bp->rx_dir;
 	pp.max_len = PAGE_SIZE;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 3aecdf099a2f..af5e0d3c8ee1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -902,6 +902,7 @@ static int mlx5e_alloc_rq(struct mlx5e_params *params,
 		pp_params.nid       = node;
 		pp_params.dev       = rq->pdev;
 		pp_params.napi      = rq->cq.napi;
+		pp_params.netdev    = rq->netdev;
 		pp_params.dma_dir   = rq->buff.map_dir;
 		pp_params.max_len   = PAGE_SIZE;
 
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index fc3d2903a80f..d1adec01299c 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -2137,6 +2137,7 @@ static int mana_create_page_pool(struct mana_rxq *rxq, struct gdma_context *gc)
 	pprm.pool_size = RX_BUFFERS_PER_QUEUE;
 	pprm.nid = gc->numa_node;
 	pprm.napi = &rxq->rx_cq.napi;
+	pprm.netdev = rxq->ndev;
 
 	rxq->page_pool = page_pool_create(&pprm);
 
diff --git a/drivers/net/ethernet/socionext/netsec.c b/drivers/net/ethernet/socionext/netsec.c
index 0891e9e49ecb..384c506bb930 100644
--- a/drivers/net/ethernet/socionext/netsec.c
+++ b/drivers/net/ethernet/socionext/netsec.c
@@ -1302,6 +1302,8 @@ static int netsec_setup_rx_dring(struct netsec_priv *priv)
 		.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,
 		.offset = NETSEC_RXBUF_HEADROOM,
 		.max_len = NETSEC_RX_BUF_SIZE,
+		.napi = priv->napi,
+		.netdev = priv->ndev,
 	};
 	int i, err;
 
-- 
2.42.0

Re: [PATCH net-next v2 07/15] eth: link netdev to page_pools in drivers

[kernel test robot]

Hi Jakub,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Jakub-Kicinski/net-page_pool-split-the-page_pool_params-into-fast-and-slow/20231121-092240
base:   net-next/main
patch link:    https://lore.kernel.org/r/20231121000048.789613-8-kuba%40kernel.org
patch subject: [PATCH net-next v2 07/15] eth: link netdev to page_pools in drivers
config: openrisc-allmodconfig (https://download.01.org/0day-ci/archive/20231121/202311212126.kJXnPMgJ-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231121/202311212126.kJXnPMgJ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311212126.kJXnPMgJ-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/net/ethernet/socionext/netsec.c: In function 'netsec_setup_rx_dring':
>> drivers/net/ethernet/socionext/netsec.c:1305:25: error: incompatible types when initializing type 'struct napi_struct *' using type 'struct napi_struct'
    1305 |                 .napi = priv->napi,
         |                         ^~~~


vim +1305 drivers/net/ethernet/socionext/netsec.c

  1290	
  1291	static int netsec_setup_rx_dring(struct netsec_priv *priv)
  1292	{
  1293		struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX];
  1294		struct bpf_prog *xdp_prog = READ_ONCE(priv->xdp_prog);
  1295		struct page_pool_params pp_params = {
  1296			.order = 0,
  1297			/* internal DMA mapping in page_pool */
  1298			.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
  1299			.pool_size = DESC_NUM,
  1300			.nid = NUMA_NO_NODE,
  1301			.dev = priv->dev,
  1302			.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,
  1303			.offset = NETSEC_RXBUF_HEADROOM,
  1304			.max_len = NETSEC_RX_BUF_SIZE,
> 1305			.napi = priv->napi,
  1306			.netdev = priv->ndev,
  1307		};
  1308		int i, err;
  1309	
  1310		dring->page_pool = page_pool_create(&pp_params);
  1311		if (IS_ERR(dring->page_pool)) {
  1312			err = PTR_ERR(dring->page_pool);
  1313			dring->page_pool = NULL;
  1314			goto err_out;
  1315		}
  1316	
  1317		err = xdp_rxq_info_reg(&dring->xdp_rxq, priv->ndev, 0, priv->napi.napi_id);
  1318		if (err)
  1319			goto err_out;
  1320	
  1321		err = xdp_rxq_info_reg_mem_model(&dring->xdp_rxq, MEM_TYPE_PAGE_POOL,
  1322						 dring->page_pool);
  1323		if (err)
  1324			goto err_out;
  1325	
  1326		for (i = 0; i < DESC_NUM; i++) {
  1327			struct netsec_desc *desc = &dring->desc[i];
  1328			dma_addr_t dma_handle;
  1329			void *buf;
  1330			u16 len;
  1331	
  1332			buf = netsec_alloc_rx_data(priv, &dma_handle, &len);
  1333	
  1334			if (!buf) {
  1335				err = -ENOMEM;
  1336				goto err_out;
  1337			}
  1338			desc->dma_addr = dma_handle;
  1339			desc->addr = buf;
  1340			desc->len = len;
  1341		}
  1342	
  1343		netsec_rx_fill(priv, 0, DESC_NUM);
  1344	
  1345		return 0;
  1346	
  1347	err_out:
  1348		netsec_uninit_pkt_dring(priv, NETSEC_RING_RX);
  1349		return err;
  1350	}
  1351	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH net-next v2 07/15] eth: link netdev to page_pools in drivers

[kernel test robot]

Hi Jakub,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Jakub-Kicinski/net-page_pool-split-the-page_pool_params-into-fast-and-slow/20231121-092240
base:   net-next/main
patch link:    https://lore.kernel.org/r/20231121000048.789613-8-kuba%40kernel.org
patch subject: [PATCH net-next v2 07/15] eth: link netdev to page_pools in drivers
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20231122/202311220437.p7reesKP-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231122/202311220437.p7reesKP-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311220437.p7reesKP-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/net/ethernet/socionext/netsec.c:1305:11: error: initializing 'struct napi_struct *' with an expression of incompatible type 'struct napi_struct'; take the address with &
                   .napi = priv->napi,
                           ^~~~~~~~~~
                           &
   1 error generated.


vim +1305 drivers/net/ethernet/socionext/netsec.c

  1290	
  1291	static int netsec_setup_rx_dring(struct netsec_priv *priv)
  1292	{
  1293		struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX];
  1294		struct bpf_prog *xdp_prog = READ_ONCE(priv->xdp_prog);
  1295		struct page_pool_params pp_params = {
  1296			.order = 0,
  1297			/* internal DMA mapping in page_pool */
  1298			.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
  1299			.pool_size = DESC_NUM,
  1300			.nid = NUMA_NO_NODE,
  1301			.dev = priv->dev,
  1302			.dma_dir = xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE,
  1303			.offset = NETSEC_RXBUF_HEADROOM,
  1304			.max_len = NETSEC_RX_BUF_SIZE,
> 1305			.napi = priv->napi,
  1306			.netdev = priv->ndev,
  1307		};
  1308		int i, err;
  1309	
  1310		dring->page_pool = page_pool_create(&pp_params);
  1311		if (IS_ERR(dring->page_pool)) {
  1312			err = PTR_ERR(dring->page_pool);
  1313			dring->page_pool = NULL;
  1314			goto err_out;
  1315		}
  1316	
  1317		err = xdp_rxq_info_reg(&dring->xdp_rxq, priv->ndev, 0, priv->napi.napi_id);
  1318		if (err)
  1319			goto err_out;
  1320	
  1321		err = xdp_rxq_info_reg_mem_model(&dring->xdp_rxq, MEM_TYPE_PAGE_POOL,
  1322						 dring->page_pool);
  1323		if (err)
  1324			goto err_out;
  1325	
  1326		for (i = 0; i < DESC_NUM; i++) {
  1327			struct netsec_desc *desc = &dring->desc[i];
  1328			dma_addr_t dma_handle;
  1329			void *buf;
  1330			u16 len;
  1331	
  1332			buf = netsec_alloc_rx_data(priv, &dma_handle, &len);
  1333	
  1334			if (!buf) {
  1335				err = -ENOMEM;
  1336				goto err_out;
  1337			}
  1338			desc->dma_addr = dma_handle;
  1339			desc->addr = buf;
  1340			desc->len = len;
  1341		}
  1342	
  1343		netsec_rx_fill(priv, 0, DESC_NUM);
  1344	
  1345		return 0;
  1346	
  1347	err_out:
  1348		netsec_uninit_pkt_dring(priv, NETSEC_RING_RX);
  1349		return err;
  1350	}
  1351	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH net-next v2 08/15] net: page_pool: add nlspec for basic access to page pools

[Jakub Kicinski]

Add a Netlink spec in YAML for getting very basic information
about page pools.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/netlink/specs/netdev.yaml | 46 +++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 14511b13f305..84ca3c2ab872 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -86,6 +86,34 @@ name: netdev
              See Documentation/networking/xdp-rx-metadata.rst for more details.
         type: u64
         enum: xdp-rx-metadata
+  -
+    name: page-pool
+    attributes:
+      -
+        name: id
+        doc: Unique ID of a Page Pool instance.
+        type: uint
+        checks:
+          min: 1
+          max: u32-max
+      -
+        name: ifindex
+        doc: |
+          ifindex of the netdev to which the pool belongs.
+          May be reported as 0 if the page pool was allocated for a netdev
+          which got destroyed already (page pools may outlast their netdevs
+          because they wait for all memory to be returned).
+        type: u32
+        checks:
+          min: 1
+          max: s32-max
+      -
+        name: napi-id
+        doc: Id of NAPI using this Page Pool instance.
+        type: uint
+        checks:
+          min: 1
+          max: u32-max
 
 operations:
   list:
@@ -120,6 +148,24 @@ name: netdev
       doc: Notification about device configuration being changed.
       notify: dev-get
       mcgrp: mgmt
+    -
+      name: page-pool-get
+      doc: |
+        Get / dump information about Page Pools.
+        (Only Page Pools associated with a net_device can be listed.)
+      attribute-set: page-pool
+      do:
+        request:
+          attributes:
+            - id
+        reply: &pp-reply
+          attributes:
+            - id
+            - ifindex
+            - napi-id
+      dump:
+        reply: *pp-reply
+      config-cond: page-pool
 
 mcast-groups:
   list:
-- 
2.42.0

Re: [PATCH net-next v2 08/15] net: page_pool: add nlspec for basic access to page pools

[Willem de Bruijn]

Jakub Kicinski wrote:
> Add a Netlink spec in YAML for getting very basic information
> about page pools.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
>  Documentation/netlink/specs/netdev.yaml | 46 +++++++++++++++++++++++++
>  1 file changed, 46 insertions(+)
> 
> diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
> index 14511b13f305..84ca3c2ab872 100644
> --- a/Documentation/netlink/specs/netdev.yaml
> +++ b/Documentation/netlink/specs/netdev.yaml
> @@ -86,6 +86,34 @@ name: netdev
>               See Documentation/networking/xdp-rx-metadata.rst for more details.
>          type: u64
>          enum: xdp-rx-metadata
> +  -
> +    name: page-pool
> +    attributes:
> +      -
> +        name: id
> +        doc: Unique ID of a Page Pool instance.
> +        type: uint
> +        checks:
> +          min: 1
> +          max: u32-max
> +      -
> +        name: ifindex
> +        doc: |
> +          ifindex of the netdev to which the pool belongs.
> +          May be reported as 0 if the page pool was allocated for a netdev
> +          which got destroyed already (page pools may outlast their netdevs
> +          because they wait for all memory to be returned).
> +        type: u32
> +        checks:
> +          min: 1
> +          max: s32-max
> +      -
> +        name: napi-id
> +        doc: Id of NAPI using this Page Pool instance.
> +        type: uint
> +        checks:
> +          min: 1
> +          max: u32-max

Do you want to introduce a separate ID for page pools? That brings some
issues regarding network namespace isolation.

As a user API, it is also possible (and intuitive?) to refer to a
page_pool by (namespacified) ifindex plus netdev_rx_queue index,
or napi_id.

In fairness, napi_id is also global, not per netns.

By iterating over "for_each_netdev(net, ..", dump already limits
output to pools in the same netns and get only reports pools that
match the netns.

So it's only a minor matter of visible numbering, and perhaps
superfluous new id.

No technical comments to this series. Looks solid to me.

Re: [PATCH net-next v2 08/15] net: page_pool: add nlspec for basic access to page pools

[Jakub Kicinski]

On Tue, 21 Nov 2023 13:24:07 -0500 Willem de Bruijn wrote:
> Do you want to introduce a separate ID for page pools? That brings some
> issues regarding network namespace isolation.
> 
> As a user API, it is also possible (and intuitive?) to refer to a
> page_pool by (namespacified) ifindex plus netdev_rx_queue index,
> or napi_id.

That does not work for "destroyed" pools. In general, there is
no natural key for a page pool I can think of.

> In fairness, napi_id is also global, not per netns.
> 
> By iterating over "for_each_netdev(net, ..", dump already limits
> output to pools in the same netns and get only reports pools that
> match the netns.
> 
> So it's only a minor matter of visible numbering, and perhaps
> superfluous new id.

The IDs are not stable. Any reconfiguration of a device will create
a new page pool and therefore assign a new ID. So applications can't
hold onto the ID long term.

That said the only use case for exposing the ID right now is to
implement do/GET (since there is no other unique key). And manual debug
with drgn, but that doesn't require uAPI. So if you prefer strongly
I can drop the ID from the uAPI and do/GET support.

Re: [PATCH net-next v2 08/15] net: page_pool: add nlspec for basic access to page pools

[Willem de Bruijn]

Jakub Kicinski wrote:
> On Tue, 21 Nov 2023 13:24:07 -0500 Willem de Bruijn wrote:
> > Do you want to introduce a separate ID for page pools? That brings some
> > issues regarding network namespace isolation.
> > 
> > As a user API, it is also possible (and intuitive?) to refer to a
> > page_pool by (namespacified) ifindex plus netdev_rx_queue index,
> > or napi_id.
> 
> That does not work for "destroyed" pools. In general, there is
> no natural key for a page pool I can think of.

Pools for destroyed devices are attached to the loopback device.
If the netns is also destroyed, would it make sense to attach
them to the loopback device in the init namespace?

> > In fairness, napi_id is also global, not per netns.
> > 
> > By iterating over "for_each_netdev(net, ..", dump already limits
> > output to pools in the same netns and get only reports pools that
> > match the netns.
> > 
> > So it's only a minor matter of visible numbering, and perhaps
> > superfluous new id.
> 
> The IDs are not stable. Any reconfiguration of a device will create
> a new page pool and therefore assign a new ID. So applications can't
> hold onto the ID long term.
> 
> That said the only use case for exposing the ID right now is to
> implement do/GET (since there is no other unique key). And manual debug
> with drgn, but that doesn't require uAPI. So if you prefer strongly
> I can drop the ID from the uAPI and do/GET support.

No, this is fine. I just wanted to make sure that the alternative api
and netns details were considered beforehand, since it's uapi.

Re: [PATCH net-next v2 08/15] net: page_pool: add nlspec for basic access to page pools

[Jakub Kicinski]

On Tue, 21 Nov 2023 16:33:25 -0500 Willem de Bruijn wrote:
> > That does not work for "destroyed" pools. In general, there is
> > no natural key for a page pool I can think of.  
> 
> Pools for destroyed devices are attached to the loopback device.
> If the netns is also destroyed, would it make sense to attach
> them to the loopback device in the init namespace?

I remember discussing this somewhere in person... netconf?
I opted for only exposing the cases which are obvious now,
we can extend the API later, once we get some production experience.

> > The IDs are not stable. Any reconfiguration of a device will create
> > a new page pool and therefore assign a new ID. So applications can't
> > hold onto the ID long term.
> > 
> > That said the only use case for exposing the ID right now is to
> > implement do/GET (since there is no other unique key). And manual debug
> > with drgn, but that doesn't require uAPI. So if you prefer strongly
> > I can drop the ID from the uAPI and do/GET support.  
> 
> No, this is fine. I just wanted to make sure that the alternative api
> and netns details were considered beforehand, since it's uapi.

Okay, let me ditch it for now, in the interest of making progress..
It's easily added later.

Re: [PATCH net-next v2 08/15] net: page_pool: add nlspec for basic access to page pools

[David Ahern]

On 11/21/23 2:00 PM, Jakub Kicinski wrote:
> On Tue, 21 Nov 2023 16:33:25 -0500 Willem de Bruijn wrote:
>>> That does not work for "destroyed" pools. In general, there is
>>> no natural key for a page pool I can think of.  
>>
>> Pools for destroyed devices are attached to the loopback device.
>> If the netns is also destroyed, would it make sense to attach
>> them to the loopback device in the init namespace?
> 
> I remember discussing this somewhere in person... netconf?

I asked why not blackhole_dev for just that problem.

Re: [PATCH net-next v2 08/15] net: page_pool: add nlspec for basic access to page pools

[Jakub Kicinski]

On Tue, 21 Nov 2023 14:49:31 -0800 David Ahern wrote:
> > I remember discussing this somewhere in person... netconf?  
> 
> I asked why not blackhole_dev for just that problem.

Ack, but I don't see myself blabbering about the hidden objects
on that sub-thread now.

[PATCH net-next v2 09/15] net: page_pool: implement GET in the netlink API

[Jakub Kicinski]

Expose the very basic page pool information via netlink.

Example using ynl-py for a system with 9 queues:

$ ./cli.py --no-schema --spec netlink/specs/netdev.yaml \
           --dump page-pool-get
[{'id': 19, 'ifindex': 2, 'napi-id': 147},
 {'id': 18, 'ifindex': 2, 'napi-id': 146},
 {'id': 17, 'ifindex': 2, 'napi-id': 145},
 {'id': 16, 'ifindex': 2, 'napi-id': 144},
 {'id': 15, 'ifindex': 2, 'napi-id': 143},
 {'id': 14, 'ifindex': 2, 'napi-id': 142},
 {'id': 13, 'ifindex': 2, 'napi-id': 141},
 {'id': 12, 'ifindex': 2, 'napi-id': 140},
 {'id': 11, 'ifindex': 2, 'napi-id': 139},
 {'id': 10, 'ifindex': 2, 'napi-id': 138}]

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/uapi/linux/netdev.h |  10 +++
 net/core/netdev-genl-gen.c  |  27 ++++++++
 net/core/netdev-genl-gen.h  |   3 +
 net/core/page_pool_user.c   | 127 ++++++++++++++++++++++++++++++++++++
 4 files changed, 167 insertions(+)

diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 2943a151d4f1..176665bcf0da 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -64,11 +64,21 @@ enum {
 	NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)
 };
 
+enum {
+	NETDEV_A_PAGE_POOL_ID = 1,
+	NETDEV_A_PAGE_POOL_IFINDEX,
+	NETDEV_A_PAGE_POOL_NAPI_ID,
+
+	__NETDEV_A_PAGE_POOL_MAX,
+	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
+};
+
 enum {
 	NETDEV_CMD_DEV_GET = 1,
 	NETDEV_CMD_DEV_ADD_NTF,
 	NETDEV_CMD_DEV_DEL_NTF,
 	NETDEV_CMD_DEV_CHANGE_NTF,
+	NETDEV_CMD_PAGE_POOL_GET,
 
 	__NETDEV_CMD_MAX,
 	NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index ea9231378aa6..9d34b451cfa7 100644
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -10,11 +10,24 @@
 
 #include <uapi/linux/netdev.h>
 
+/* Integer value ranges */
+static const struct netlink_range_validation netdev_a_page_pool_id_range = {
+	.min	= 1,
+	.max	= 4294967295,
+};
+
 /* NETDEV_CMD_DEV_GET - do */
 static const struct nla_policy netdev_dev_get_nl_policy[NETDEV_A_DEV_IFINDEX + 1] = {
 	[NETDEV_A_DEV_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
 };
 
+/* NETDEV_CMD_PAGE_POOL_GET - do */
+#ifdef CONFIG_PAGE_POOL
+static const struct nla_policy netdev_page_pool_get_nl_policy[NETDEV_A_PAGE_POOL_ID + 1] = {
+	[NETDEV_A_PAGE_POOL_ID] = NLA_POLICY_FULL_RANGE(NLA_UINT, &netdev_a_page_pool_id_range),
+};
+#endif /* CONFIG_PAGE_POOL */
+
 /* Ops table for netdev */
 static const struct genl_split_ops netdev_nl_ops[] = {
 	{
@@ -29,6 +42,20 @@ static const struct genl_split_ops netdev_nl_ops[] = {
 		.dumpit	= netdev_nl_dev_get_dumpit,
 		.flags	= GENL_CMD_CAP_DUMP,
 	},
+#ifdef CONFIG_PAGE_POOL
+	{
+		.cmd		= NETDEV_CMD_PAGE_POOL_GET,
+		.doit		= netdev_nl_page_pool_get_doit,
+		.policy		= netdev_page_pool_get_nl_policy,
+		.maxattr	= NETDEV_A_PAGE_POOL_ID,
+		.flags		= GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NETDEV_CMD_PAGE_POOL_GET,
+		.dumpit	= netdev_nl_page_pool_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
+#endif /* CONFIG_PAGE_POOL */
 };
 
 static const struct genl_multicast_group netdev_nl_mcgrps[] = {
diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h
index 7b370c073e7d..a011d12abff4 100644
--- a/net/core/netdev-genl-gen.h
+++ b/net/core/netdev-genl-gen.h
@@ -13,6 +13,9 @@
 
 int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info);
 int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int netdev_nl_page_pool_get_doit(struct sk_buff *skb, struct genl_info *info);
+int netdev_nl_page_pool_get_dumpit(struct sk_buff *skb,
+				   struct netlink_callback *cb);
 
 enum {
 	NETDEV_NLGRP_MGMT,
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 23074d4c75fc..24f4e54f6266 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -5,8 +5,10 @@
 #include <linux/xarray.h>
 #include <net/net_debug.h>
 #include <net/page_pool/types.h>
+#include <net/sock.h>
 
 #include "page_pool_priv.h"
+#include "netdev-genl-gen.h"
 
 static DEFINE_XARRAY_FLAGS(page_pools, XA_FLAGS_ALLOC1);
 /* Protects: page_pools, netdevice->page_pools, pool->slow.netdev, pool->user.
@@ -26,6 +28,131 @@ static DEFINE_MUTEX(page_pools_lock);
  *    - user.list: unhashed, netdev: unknown
  */
 
+typedef int (*pp_nl_fill_cb)(struct sk_buff *rsp, const struct page_pool *pool,
+			     const struct genl_info *info);
+
+static int
+netdev_nl_page_pool_get_do(struct genl_info *info, u32 id, pp_nl_fill_cb fill)
+{
+	struct page_pool *pool;
+	struct sk_buff *rsp;
+	int err;
+
+	mutex_lock(&page_pools_lock);
+	pool = xa_load(&page_pools, id);
+	if (!pool || hlist_unhashed(&pool->user.list) ||
+	    !net_eq(dev_net(pool->slow.netdev), genl_info_net(info))) {
+		err = -ENOENT;
+		goto err_unlock;
+	}
+
+	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!rsp) {
+		err = -ENOMEM;
+		goto err_unlock;
+	}
+
+	err = fill(rsp, pool, info);
+	if (err)
+		goto err_free_msg;
+
+	mutex_unlock(&page_pools_lock);
+
+	return genlmsg_reply(rsp, info);
+
+err_free_msg:
+	nlmsg_free(rsp);
+err_unlock:
+	mutex_unlock(&page_pools_lock);
+	return err;
+}
+
+struct page_pool_dump_cb {
+	unsigned long ifindex;
+	u32 pp_id;
+};
+
+static int
+netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
+			     pp_nl_fill_cb fill)
+{
+	struct page_pool_dump_cb *state = (void *)cb->ctx;
+	const struct genl_info *info = genl_info_dump(cb);
+	struct net *net = sock_net(skb->sk);
+	struct net_device *netdev;
+	struct page_pool *pool;
+	int err = 0;
+
+	rtnl_lock();
+	mutex_lock(&page_pools_lock);
+	for_each_netdev_dump(net, netdev, state->ifindex) {
+		hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
+			if (state->pp_id && state->pp_id < pool->user.id)
+				continue;
+
+			state->pp_id = pool->user.id;
+			err = fill(skb, pool, info);
+			if (err)
+				break;
+		}
+
+		state->pp_id = 0;
+	}
+	mutex_unlock(&page_pools_lock);
+	rtnl_unlock();
+
+	if (skb->len && err == -EMSGSIZE)
+		return skb->len;
+	return err;
+}
+
+static int
+page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
+		  const struct genl_info *info)
+{
+	void *hdr;
+
+	hdr = genlmsg_iput(rsp, info);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_ID, pool->user.id))
+		goto err_cancel;
+
+	if (pool->slow.netdev->ifindex != LOOPBACK_IFINDEX &&
+	    nla_put_u32(rsp, NETDEV_A_PAGE_POOL_IFINDEX,
+			pool->slow.netdev->ifindex))
+		goto err_cancel;
+	if (pool->user.napi_id &&
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_NAPI_ID, pool->user.napi_id))
+		goto err_cancel;
+
+	genlmsg_end(rsp, hdr);
+
+	return 0;
+err_cancel:
+	genlmsg_cancel(rsp, hdr);
+	return -EMSGSIZE;
+}
+
+int netdev_nl_page_pool_get_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	u32 id;
+
+	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_PAGE_POOL_ID))
+		return -EINVAL;
+
+	id = nla_get_uint(info->attrs[NETDEV_A_PAGE_POOL_ID]);
+
+	return netdev_nl_page_pool_get_do(info, id, page_pool_nl_fill);
+}
+
+int netdev_nl_page_pool_get_dumpit(struct sk_buff *skb,
+				   struct netlink_callback *cb)
+{
+	return netdev_nl_page_pool_get_dump(skb, cb, page_pool_nl_fill);
+}
+
 int page_pool_list(struct page_pool *pool)
 {
 	static u32 id_alloc_next;
-- 
2.42.0

[PATCH net-next v2 10/15] net: page_pool: add netlink notifications for state changes

[Jakub Kicinski]

Generate netlink notifications about page pool state changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/netlink/specs/netdev.yaml | 20 ++++++++++++++
 include/uapi/linux/netdev.h             |  4 +++
 net/core/netdev-genl-gen.c              |  1 +
 net/core/netdev-genl-gen.h              |  1 +
 net/core/page_pool_user.c               | 36 +++++++++++++++++++++++++
 5 files changed, 62 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 84ca3c2ab872..82fbe81f7a49 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -166,8 +166,28 @@ name: netdev
       dump:
         reply: *pp-reply
       config-cond: page-pool
+    -
+      name: page-pool-add-ntf
+      doc: Notification about page pool appearing.
+      notify: page-pool-get
+      mcgrp: page-pool
+      config-cond: page-pool
+    -
+      name: page-pool-del-ntf
+      doc: Notification about page pool disappearing.
+      notify: page-pool-get
+      mcgrp: page-pool
+      config-cond: page-pool
+    -
+      name: page-pool-change-ntf
+      doc: Notification about page pool configuration being changed.
+      notify: page-pool-get
+      mcgrp: page-pool
+      config-cond: page-pool
 
 mcast-groups:
   list:
     -
       name: mgmt
+    -
+      name: page-pool
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 176665bcf0da..beb158872226 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -79,11 +79,15 @@ enum {
 	NETDEV_CMD_DEV_DEL_NTF,
 	NETDEV_CMD_DEV_CHANGE_NTF,
 	NETDEV_CMD_PAGE_POOL_GET,
+	NETDEV_CMD_PAGE_POOL_ADD_NTF,
+	NETDEV_CMD_PAGE_POOL_DEL_NTF,
+	NETDEV_CMD_PAGE_POOL_CHANGE_NTF,
 
 	__NETDEV_CMD_MAX,
 	NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
 };
 
 #define NETDEV_MCGRP_MGMT	"mgmt"
+#define NETDEV_MCGRP_PAGE_POOL	"page-pool"
 
 #endif /* _UAPI_LINUX_NETDEV_H */
diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index 9d34b451cfa7..278b43f5ed50 100644
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -60,6 +60,7 @@ static const struct genl_split_ops netdev_nl_ops[] = {
 
 static const struct genl_multicast_group netdev_nl_mcgrps[] = {
 	[NETDEV_NLGRP_MGMT] = { "mgmt", },
+	[NETDEV_NLGRP_PAGE_POOL] = { "page-pool", },
 };
 
 struct genl_family netdev_nl_family __ro_after_init = {
diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h
index a011d12abff4..738097847100 100644
--- a/net/core/netdev-genl-gen.h
+++ b/net/core/netdev-genl-gen.h
@@ -19,6 +19,7 @@ int netdev_nl_page_pool_get_dumpit(struct sk_buff *skb,
 
 enum {
 	NETDEV_NLGRP_MGMT,
+	NETDEV_NLGRP_PAGE_POOL,
 };
 
 extern struct genl_family netdev_nl_family;
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 24f4e54f6266..35c56fb41c46 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -135,6 +135,37 @@ page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
 	return -EMSGSIZE;
 }
 
+static void netdev_nl_page_pool_event(const struct page_pool *pool, u32 cmd)
+{
+	struct genl_info info;
+	struct sk_buff *ntf;
+	struct net *net;
+
+	lockdep_assert_held(&page_pools_lock);
+
+	/* 'invisible' page pools don't matter */
+	if (hlist_unhashed(&pool->user.list))
+		return;
+	net = dev_net(pool->slow.netdev);
+
+	if (!genl_has_listeners(&netdev_nl_family, net, NETDEV_NLGRP_PAGE_POOL))
+		return;
+
+	genl_info_init_ntf(&info, &netdev_nl_family, cmd);
+
+	ntf = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!ntf)
+		return;
+
+	if (page_pool_nl_fill(ntf, pool, &info)) {
+		nlmsg_free(ntf);
+		return;
+	}
+
+	genlmsg_multicast_netns(&netdev_nl_family, net, ntf,
+				0, NETDEV_NLGRP_PAGE_POOL, GFP_KERNEL);
+}
+
 int netdev_nl_page_pool_get_doit(struct sk_buff *skb, struct genl_info *info)
 {
 	u32 id;
@@ -168,6 +199,8 @@ int page_pool_list(struct page_pool *pool)
 		hlist_add_head(&pool->user.list,
 			       &pool->slow.netdev->page_pools);
 		pool->user.napi_id = pool->p.napi ? pool->p.napi->napi_id : 0;
+
+		netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_ADD_NTF);
 	}
 
 	mutex_unlock(&page_pools_lock);
@@ -181,6 +214,7 @@ int page_pool_list(struct page_pool *pool)
 void page_pool_unlist(struct page_pool *pool)
 {
 	mutex_lock(&page_pools_lock);
+	netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_DEL_NTF);
 	xa_erase(&page_pools, pool->user.id);
 	hlist_del(&pool->user.list);
 	mutex_unlock(&page_pools_lock);
@@ -216,6 +250,8 @@ static void page_pool_unreg_netdev(struct net_device *netdev)
 	last = NULL;
 	hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
 		pool->slow.netdev = lo;
+		netdev_nl_page_pool_event(pool,
+					  NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
 		last = pool;
 	}
 	if (last)
-- 
2.42.0

[PATCH net-next v2 11/15] net: page_pool: report amount of memory held by page pools

[Jakub Kicinski]

Advanced deployments need the ability to check memory use
of various system components. It makes it possible to make informed
decisions about memory allocation and to find regressions and leaks.

Report memory use of page pools. Report both number of references
and bytes held.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/netlink/specs/netdev.yaml | 13 +++++++++++++
 include/uapi/linux/netdev.h             |  2 ++
 net/core/page_pool.c                    | 13 +++++++++----
 net/core/page_pool_priv.h               |  2 ++
 net/core/page_pool_user.c               |  8 ++++++++
 5 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 82fbe81f7a49..85209e19dca9 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -114,6 +114,17 @@ name: netdev
         checks:
           min: 1
           max: u32-max
+      -
+        name: inflight
+        type: uint
+        doc: |
+          Number of outstanding references to this page pool (allocated
+          but yet to be freed pages).
+      -
+        name: inflight-mem
+        type: uint
+        doc: |
+          Amount of memory held by inflight pages.
 
 operations:
   list:
@@ -163,6 +174,8 @@ name: netdev
             - id
             - ifindex
             - napi-id
+            - inflight
+            - inflight-mem
       dump:
         reply: *pp-reply
       config-cond: page-pool
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index beb158872226..26ae5bdd3187 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -68,6 +68,8 @@ enum {
 	NETDEV_A_PAGE_POOL_ID = 1,
 	NETDEV_A_PAGE_POOL_IFINDEX,
 	NETDEV_A_PAGE_POOL_NAPI_ID,
+	NETDEV_A_PAGE_POOL_INFLIGHT,
+	NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
 
 	__NETDEV_A_PAGE_POOL_MAX,
 	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index a8d96ea38d18..566390759294 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -529,7 +529,7 @@ EXPORT_SYMBOL(page_pool_alloc_pages);
  */
 #define _distance(a, b)	(s32)((a) - (b))
 
-static s32 page_pool_inflight(struct page_pool *pool)
+s32 page_pool_inflight(const struct page_pool *pool, bool strict)
 {
 	u32 release_cnt = atomic_read(&pool->pages_state_release_cnt);
 	u32 hold_cnt = READ_ONCE(pool->pages_state_hold_cnt);
@@ -537,8 +537,13 @@ static s32 page_pool_inflight(struct page_pool *pool)
 
 	inflight = _distance(hold_cnt, release_cnt);
 
-	trace_page_pool_release(pool, inflight, hold_cnt, release_cnt);
-	WARN(inflight < 0, "Negative(%d) inflight packet-pages", inflight);
+	if (strict) {
+		trace_page_pool_release(pool, inflight, hold_cnt, release_cnt);
+		WARN(inflight < 0, "Negative(%d) inflight packet-pages",
+		     inflight);
+	} else {
+		inflight = max(0, inflight);
+	}
 
 	return inflight;
 }
@@ -881,7 +886,7 @@ static int page_pool_release(struct page_pool *pool)
 	int inflight;
 
 	page_pool_scrub(pool);
-	inflight = page_pool_inflight(pool);
+	inflight = page_pool_inflight(pool, true);
 	if (!inflight)
 		__page_pool_destroy(pool);
 
diff --git a/net/core/page_pool_priv.h b/net/core/page_pool_priv.h
index c17ea092b4ab..72fb21ea1ddc 100644
--- a/net/core/page_pool_priv.h
+++ b/net/core/page_pool_priv.h
@@ -3,6 +3,8 @@
 #ifndef __PAGE_POOL_PRIV_H
 #define __PAGE_POOL_PRIV_H
 
+s32 page_pool_inflight(const struct page_pool *pool, bool strict);
+
 int page_pool_list(struct page_pool *pool);
 void page_pool_unlist(struct page_pool *pool);
 
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index 35c56fb41c46..d889b347f8f4 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -110,6 +110,7 @@ static int
 page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
 		  const struct genl_info *info)
 {
+	size_t inflight, refsz;
 	void *hdr;
 
 	hdr = genlmsg_iput(rsp, info);
@@ -127,6 +128,13 @@ page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_NAPI_ID, pool->user.napi_id))
 		goto err_cancel;
 
+	inflight = page_pool_inflight(pool, false);
+	refsz =	PAGE_SIZE << pool->p.order;
+	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT, inflight) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
+			 inflight * refsz))
+		goto err_cancel;
+
 	genlmsg_end(rsp, hdr);
 
 	return 0;
-- 
2.42.0

[PATCH net-next v2 12/15] net: page_pool: report when page pool was destroyed

[Jakub Kicinski]

Report when page pool was destroyed. Together with the inflight
/ memory use reporting this can serve as a replacement for the
warning about leaked page pools we currently print to dmesg.

Example output for a fake leaked page pool using some hacks
in netdevsim (one "live" pool, and one "leaked" on the same dev):

$ ./cli.py --no-schema --spec netlink/specs/netdev.yaml \
           --dump page-pool-get
[{'id': 2, 'ifindex': 3},
 {'id': 1, 'ifindex': 3, 'destroyed': 133, 'inflight': 1}]

Tested-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/netlink/specs/netdev.yaml |  9 +++++++++
 include/net/page_pool/types.h           |  1 +
 include/uapi/linux/netdev.h             |  1 +
 net/core/page_pool.c                    |  1 +
 net/core/page_pool_priv.h               |  1 +
 net/core/page_pool_user.c               | 12 ++++++++++++
 6 files changed, 25 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 85209e19dca9..8dafa2a8a4dd 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -125,6 +125,14 @@ name: netdev
         type: uint
         doc: |
           Amount of memory held by inflight pages.
+      -
+        name: destroyed
+        type: uint
+        doc: |
+          Seconds in CLOCK_BOOTTIME of when Page Pool was destroyed.
+          Page Pools wait for all the memory allocated from them to be freed
+          before truly disappearing.
+          Absent if Page Pool hasn't been destroyed.
 
 operations:
   list:
@@ -176,6 +184,7 @@ name: netdev
             - napi-id
             - inflight
             - inflight-mem
+            - destroyed
       dump:
         reply: *pp-reply
       config-cond: page-pool
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 7e47d7bb2c1e..f0c51ef5e345 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -193,6 +193,7 @@ struct page_pool {
 	/* User-facing fields, protected by page_pools_lock */
 	struct {
 		struct hlist_node list;
+		u64 destroyed;
 		u32 napi_id;
 		u32 id;
 	} user;
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 26ae5bdd3187..e5bf66d2aa31 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -70,6 +70,7 @@ enum {
 	NETDEV_A_PAGE_POOL_NAPI_ID,
 	NETDEV_A_PAGE_POOL_INFLIGHT,
 	NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
+	NETDEV_A_PAGE_POOL_DESTROYED,
 
 	__NETDEV_A_PAGE_POOL_MAX,
 	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 566390759294..0f3f525c457a 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -953,6 +953,7 @@ void page_pool_destroy(struct page_pool *pool)
 	if (!page_pool_release(pool))
 		return;
 
+	page_pool_destroyed(pool);
 	pool->defer_start = jiffies;
 	pool->defer_warn  = jiffies + DEFER_WARN_INTERVAL;
 
diff --git a/net/core/page_pool_priv.h b/net/core/page_pool_priv.h
index 72fb21ea1ddc..7fe6f842a270 100644
--- a/net/core/page_pool_priv.h
+++ b/net/core/page_pool_priv.h
@@ -6,6 +6,7 @@
 s32 page_pool_inflight(const struct page_pool *pool, bool strict);
 
 int page_pool_list(struct page_pool *pool);
+void page_pool_destroyed(struct page_pool *pool);
 void page_pool_unlist(struct page_pool *pool);
 
 #endif
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index d889b347f8f4..d0f778f358fc 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -134,6 +134,10 @@ page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
 			 inflight * refsz))
 		goto err_cancel;
+	if (pool->user.destroyed &&
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_DESTROYED,
+			 pool->user.destroyed))
+		goto err_cancel;
 
 	genlmsg_end(rsp, hdr);
 
@@ -219,6 +223,14 @@ int page_pool_list(struct page_pool *pool)
 	return err;
 }
 
+void page_pool_destroyed(struct page_pool *pool)
+{
+	mutex_lock(&page_pools_lock);
+	pool->user.destroyed = ktime_get_boottime_seconds();
+	netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
+	mutex_unlock(&page_pools_lock);
+}
+
 void page_pool_unlist(struct page_pool *pool)
 {
 	mutex_lock(&page_pools_lock);
-- 
2.42.0

Re: [PATCH net-next v2 12/15] net: page_pool: report when page pool was destroyed

[Jesper Dangaard Brouer]

On 11/21/23 01:00, Jakub Kicinski wrote:

> Report when page pool was destroyed. Together with the inflight
> / memory use reporting this can serve as a replacement for the
> warning about leaked page pools we currently print to dmesg.
>
> Example output for a fake leaked page pool using some hacks
> in netdevsim (one "live" pool, and one "leaked" on the same dev):
>
> $ ./cli.py --no-schema --spec netlink/specs/netdev.yaml \
>             --dump page-pool-get
> [{'id': 2, 'ifindex': 3},
>   {'id': 1, 'ifindex': 3, 'destroyed': 133, 'inflight': 1}]
>
> Tested-by: Dragos Tatulea <dtatulea@nvidia.com>
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
>   Documentation/netlink/specs/netdev.yaml |  9 +++++++++
>   include/net/page_pool/types.h           |  1 +
>   include/uapi/linux/netdev.h             |  1 +
>   net/core/page_pool.c                    |  1 +
>   net/core/page_pool_priv.h               |  1 +
>   net/core/page_pool_user.c               | 12 ++++++++++++
>   6 files changed, 25 insertions(+)
>
> diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
> index 85209e19dca9..8dafa2a8a4dd 100644
> --- a/Documentation/netlink/specs/netdev.yaml
> +++ b/Documentation/netlink/specs/netdev.yaml
> @@ -125,6 +125,14 @@ name: netdev
>           type: uint
>           doc: |
>             Amount of memory held by inflight pages.
> +      -
> +        name: destroyed
> +        type: uint
> +        doc: |
> +          Seconds in CLOCK_BOOTTIME of when Page Pool was destroyed.
> +          Page Pools wait for all the memory allocated from them to be freed
> +          before truly disappearing.
> +          Absent if Page Pool hasn't been destroyed.
>   
>   operations:
>     list:
> @@ -176,6 +184,7 @@ name: netdev
>               - napi-id
>               - inflight
>               - inflight-mem
> +            - destroyed
>         dump:
>           reply: *pp-reply
>         config-cond: page-pool
> diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
> index 7e47d7bb2c1e..f0c51ef5e345 100644
> --- a/include/net/page_pool/types.h
> +++ b/include/net/page_pool/types.h
> @@ -193,6 +193,7 @@ struct page_pool {
>   	/* User-facing fields, protected by page_pools_lock */
>   	struct {
>   		struct hlist_node list;
> +		u64 destroyed;
>   		u32 napi_id;
>   		u32 id;
>   	} user;
> diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
> index 26ae5bdd3187..e5bf66d2aa31 100644
> --- a/include/uapi/linux/netdev.h
> +++ b/include/uapi/linux/netdev.h
> @@ -70,6 +70,7 @@ enum {
>   	NETDEV_A_PAGE_POOL_NAPI_ID,
>   	NETDEV_A_PAGE_POOL_INFLIGHT,
>   	NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
> +	NETDEV_A_PAGE_POOL_DESTROYED,
>   
>   	__NETDEV_A_PAGE_POOL_MAX,
>   	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index 566390759294..0f3f525c457a 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -953,6 +953,7 @@ void page_pool_destroy(struct page_pool *pool)
>   	if (!page_pool_release(pool))
>   		return;
>   
> +	page_pool_destroyed(pool);
Hmm, this is called when kernel could *NOT* destroy the PP, but have to 
start a work-queue that will retry deleting this. Thus, I think naming 
this "destroyed" is confusing as I then assumed was successfully 
destroyed, but it is not, instead it is on "deathrow".


>   	pool->defer_start = jiffies;
>   	pool->defer_warn  = jiffies + DEFER_WARN_INTERVAL;
>   
> diff --git a/net/core/page_pool_priv.h b/net/core/page_pool_priv.h
> index 72fb21ea1ddc..7fe6f842a270 100644
> --- a/net/core/page_pool_priv.h
> +++ b/net/core/page_pool_priv.h
> @@ -6,6 +6,7 @@
>   s32 page_pool_inflight(const struct page_pool *pool, bool strict);
>   
>   int page_pool_list(struct page_pool *pool);
> +void page_pool_destroyed(struct page_pool *pool);
>   void page_pool_unlist(struct page_pool *pool);
>   
>   #endif
> diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
> index d889b347f8f4..d0f778f358fc 100644
> --- a/net/core/page_pool_user.c
> +++ b/net/core/page_pool_user.c
> @@ -134,6 +134,10 @@ page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
>   	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
>   			 inflight * refsz))
>   		goto err_cancel;
> +	if (pool->user.destroyed &&
> +	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_DESTROYED,
> +			 pool->user.destroyed))
> +		goto err_cancel;
>   
>   	genlmsg_end(rsp, hdr);
>   
> @@ -219,6 +223,14 @@ int page_pool_list(struct page_pool *pool)
>   	return err;
>   }
>   
> +void page_pool_destroyed(struct page_pool *pool)
> +{
> +	mutex_lock(&page_pools_lock);
> +	pool->user.destroyed = ktime_get_boottime_seconds();
> +	netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_CHANGE_NTF);

Could we place this PP instance on another list of PP instances about to 
be deleted?

(e.g. a deathrow or sched_destroy list)


Perhaps this could also allow us to list those PP instances that 
no-longer have a netdev associated?


> +	mutex_unlock(&page_pools_lock);
> +}

Re: [PATCH net-next v2 12/15] net: page_pool: report when page pool was destroyed

[Jakub Kicinski]

On Tue, 21 Nov 2023 21:45:57 +0100 Jesper Dangaard Brouer wrote:
> Hmm, this is called when kernel could *NOT* destroy the PP, but have to 
> start a work-queue that will retry deleting this. Thus, I think naming 
> this "destroyed" is confusing as I then assumed was successfully 
> destroyed, but it is not, instead it is on "deathrow".

I wasn't sure what to call it so I called what the driver API is
called...

"deathrow" does not sound very intuitive to me. How about "detached"
or "removed"?

> Could we place this PP instance on another list of PP instances about to 
> be deleted?
> 
> (e.g. a deathrow or sched_destroy list)

Is there a need for that?

I mean - many interesting extensions to this API are possible.
I don't think they should all can all be here from day 1..

> Perhaps this could also allow us to list those PP instances that 
> no-longer have a netdev associated?

The current implementation uses loopback for that, since it's naturally
tied to a name space.

Re: [PATCH net-next v2 12/15] net: page_pool: report when page pool was destroyed

[Jesper Dangaard Brouer]

On 11/21/23 22:49, Jakub Kicinski wrote:
> On Tue, 21 Nov 2023 21:45:57 +0100 Jesper Dangaard Brouer wrote:
>> Hmm, this is called when kernel could *NOT* destroy the PP, but have to
>> start a work-queue that will retry deleting this. Thus, I think naming
>> this "destroyed" is confusing as I then assumed was successfully
>> destroyed, but it is not, instead it is on "deathrow".
> 
> I wasn't sure what to call it so I called what the driver API is
> called...
> 
> "deathrow" does not sound very intuitive to me. How about "detached"
> or "removed"?

I like "detached".

> 
>> Could we place this PP instance on another list of PP instances about to
>> be deleted?
>>
>> (e.g. a deathrow or sched_destroy list)
> 
> Is there a need for that?
> 
> I mean - many interesting extensions to this API are possible.
> I don't think they should all can all be here from day 1..
> 
>> Perhaps this could also allow us to list those PP instances that
>> no-longer have a netdev associated?
> 
> The current implementation uses loopback for that, since it's naturally
> tied to a name space.

Okay, guess it makes sense to tie this to loopback.

--Jesper

[PATCH net-next v2 13/15] net: page_pool: expose page pool stats via netlink

[Jakub Kicinski]

Dump the stats into netlink. More clever approaches
like dumping the stats per-CPU for each CPU individually
to see where the packets get consumed can be implemented
in the future.

A trimmed example from a real (but recently booted system):

$ ./cli.py --no-schema --spec netlink/specs/netdev.yaml \
           --dump page-pool-stats-get
[{'info': {'id': 19, 'ifindex': 2},
  'alloc-empty': 48,
  'alloc-fast': 3024,
  'alloc-refill': 0,
  'alloc-slow': 48,
  'alloc-slow-high-order': 0,
  'alloc-waive': 0,
  'recycle-cache-full': 0,
  'recycle-cached': 0,
  'recycle-released-refcnt': 0,
  'recycle-ring': 0,
  'recycle-ring-full': 0},
 {'info': {'id': 18, 'ifindex': 2},
  'alloc-empty': 66,
  'alloc-fast': 11811,
  'alloc-refill': 35,
  'alloc-slow': 66,
  'alloc-slow-high-order': 0,
  'alloc-waive': 0,
  'recycle-cache-full': 1145,
  'recycle-cached': 6541,
  'recycle-released-refcnt': 0,
  'recycle-ring': 1275,
  'recycle-ring-full': 0},
 {'info': {'id': 17, 'ifindex': 2},
  'alloc-empty': 73,
  'alloc-fast': 62099,
  'alloc-refill': 413,
...

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/netlink/specs/netdev.yaml |  78 ++++++++++++++++++
 Documentation/networking/page_pool.rst  |  10 ++-
 include/net/page_pool/helpers.h         |   8 +-
 include/uapi/linux/netdev.h             |  19 +++++
 net/core/netdev-genl-gen.c              |  32 ++++++++
 net/core/netdev-genl-gen.h              |   7 ++
 net/core/page_pool.c                    |   2 +-
 net/core/page_pool_user.c               | 103 ++++++++++++++++++++++++
 8 files changed, 250 insertions(+), 9 deletions(-)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 8dafa2a8a4dd..58f9996391b0 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -133,6 +133,59 @@ name: netdev
           Page Pools wait for all the memory allocated from them to be freed
           before truly disappearing.
           Absent if Page Pool hasn't been destroyed.
+  -
+    name: page-pool-info
+    subset-of: page-pool
+    attributes:
+      -
+        name: id
+      -
+        name: ifindex
+  -
+    name: page-pool-stats
+    doc: |
+      Page pool statistics, see docs for struct page_pool_stats
+      for information about individual statistics.
+    attributes:
+      -
+        name: info
+        doc: Page pool identifying information.
+        type: nest
+        nested-attributes: page-pool-info
+      -
+        name: alloc-fast
+        type: uint
+        value: 8 # reserve some attr ids in case we need more metadata later
+      -
+        name: alloc-slow
+        type: uint
+      -
+        name: alloc-slow-high-order
+        type: uint
+      -
+        name: alloc-empty
+        type: uint
+      -
+        name: alloc-refill
+        type: uint
+      -
+        name: alloc-waive
+        type: uint
+      -
+        name: recycle-cached
+        type: uint
+      -
+        name: recycle-cache-full
+        type: uint
+      -
+        name: recycle-ring
+        type: uint
+      -
+        name: recycle-ring-full
+        type: uint
+      -
+        name: recycle-released-refcnt
+        type: uint
 
 operations:
   list:
@@ -206,6 +259,31 @@ name: netdev
       notify: page-pool-get
       mcgrp: page-pool
       config-cond: page-pool
+    -
+      name: page-pool-stats-get
+      doc: Get page pool statistics.
+      attribute-set: page-pool-stats
+      do:
+        request:
+          attributes:
+            - info
+        reply: &pp-stats-reply
+          attributes:
+            - info
+            - alloc-fast
+            - alloc-slow
+            - alloc-slow-high-order
+            - alloc-empty
+            - alloc-refill
+            - alloc-waive
+            - recycle-cached
+            - recycle-cache-full
+            - recycle-ring
+            - recycle-ring-full
+            - recycle-released-refcnt
+      dump:
+        reply: *pp-stats-reply
+      config-cond: page-pool-stats
 
 mcast-groups:
   list:
diff --git a/Documentation/networking/page_pool.rst b/Documentation/networking/page_pool.rst
index 60993cb56b32..9d958128a57c 100644
--- a/Documentation/networking/page_pool.rst
+++ b/Documentation/networking/page_pool.rst
@@ -41,6 +41,11 @@ Architecture overview
                           |   Fast cache    |     |  ptr-ring cache  |
                           +-----------------+     +------------------+
 
+Monitoring
+==========
+Information about page pools on the system can be accessed via the netdev
+genetlink family (see Documentation/netlink/specs/netdev.yaml).
+
 API interface
 =============
 The number of pools created **must** match the number of hardware queues
@@ -107,8 +112,9 @@ page_pool_get_stats() and structures described below are available.
 It takes a  pointer to a ``struct page_pool`` and a pointer to a struct
 page_pool_stats allocated by the caller.
 
-The API will fill in the provided struct page_pool_stats with
-statistics about the page_pool.
+Older drivers expose page pool statistics via ethtool or debugfs.
+The same statistics are accessible via the netlink netdev family
+in a driver-independent fashion.
 
 .. kernel-doc:: include/net/page_pool/types.h
    :identifiers: struct page_pool_recycle_stats
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index 4ebd544ae977..7dc65774cde5 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -55,16 +55,12 @@
 #include <net/page_pool/types.h>
 
 #ifdef CONFIG_PAGE_POOL_STATS
+/* Deprecated driver-facing API, use netlink instead */
 int page_pool_ethtool_stats_get_count(void);
 u8 *page_pool_ethtool_stats_get_strings(u8 *data);
 u64 *page_pool_ethtool_stats_get(u64 *data, void *stats);
 
-/*
- * Drivers that wish to harvest page pool stats and report them to users
- * (perhaps via ethtool, debugfs, or another mechanism) can allocate a
- * struct page_pool_stats call page_pool_get_stats to get stats for the specified pool.
- */
-bool page_pool_get_stats(struct page_pool *pool,
+bool page_pool_get_stats(const struct page_pool *pool,
 			 struct page_pool_stats *stats);
 #else
 static inline int page_pool_ethtool_stats_get_count(void)
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index e5bf66d2aa31..9d0a48717d1f 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -76,6 +76,24 @@ enum {
 	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
 };
 
+enum {
+	NETDEV_A_PAGE_POOL_STATS_INFO = 1,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_FAST = 8,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW_HIGH_ORDER,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_EMPTY,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_REFILL,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_WAIVE,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHED,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHE_FULL,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING_FULL,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_RELEASED_REFCNT,
+
+	__NETDEV_A_PAGE_POOL_STATS_MAX,
+	NETDEV_A_PAGE_POOL_STATS_MAX = (__NETDEV_A_PAGE_POOL_STATS_MAX - 1)
+};
+
 enum {
 	NETDEV_CMD_DEV_GET = 1,
 	NETDEV_CMD_DEV_ADD_NTF,
@@ -85,6 +103,7 @@ enum {
 	NETDEV_CMD_PAGE_POOL_ADD_NTF,
 	NETDEV_CMD_PAGE_POOL_DEL_NTF,
 	NETDEV_CMD_PAGE_POOL_CHANGE_NTF,
+	NETDEV_CMD_PAGE_POOL_STATS_GET,
 
 	__NETDEV_CMD_MAX,
 	NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index 278b43f5ed50..b8af054b9fe5 100644
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -16,6 +16,17 @@ static const struct netlink_range_validation netdev_a_page_pool_id_range = {
 	.max	= 4294967295,
 };
 
+static const struct netlink_range_validation netdev_a_page_pool_ifindex_range = {
+	.min	= 1,
+	.max	= 2147483647,
+};
+
+/* Common nested types */
+const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFINDEX + 1] = {
+	[NETDEV_A_PAGE_POOL_ID] = NLA_POLICY_FULL_RANGE(NLA_UINT, &netdev_a_page_pool_id_range),
+	[NETDEV_A_PAGE_POOL_IFINDEX] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_page_pool_ifindex_range),
+};
+
 /* NETDEV_CMD_DEV_GET - do */
 static const struct nla_policy netdev_dev_get_nl_policy[NETDEV_A_DEV_IFINDEX + 1] = {
 	[NETDEV_A_DEV_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
@@ -28,6 +39,13 @@ static const struct nla_policy netdev_page_pool_get_nl_policy[NETDEV_A_PAGE_POOL
 };
 #endif /* CONFIG_PAGE_POOL */
 
+/* NETDEV_CMD_PAGE_POOL_STATS_GET - do */
+#ifdef CONFIG_PAGE_POOL_STATS
+static const struct nla_policy netdev_page_pool_stats_get_nl_policy[NETDEV_A_PAGE_POOL_STATS_INFO + 1] = {
+	[NETDEV_A_PAGE_POOL_STATS_INFO] = NLA_POLICY_NESTED(netdev_page_pool_info_nl_policy),
+};
+#endif /* CONFIG_PAGE_POOL_STATS */
+
 /* Ops table for netdev */
 static const struct genl_split_ops netdev_nl_ops[] = {
 	{
@@ -56,6 +74,20 @@ static const struct genl_split_ops netdev_nl_ops[] = {
 		.flags	= GENL_CMD_CAP_DUMP,
 	},
 #endif /* CONFIG_PAGE_POOL */
+#ifdef CONFIG_PAGE_POOL_STATS
+	{
+		.cmd		= NETDEV_CMD_PAGE_POOL_STATS_GET,
+		.doit		= netdev_nl_page_pool_stats_get_doit,
+		.policy		= netdev_page_pool_stats_get_nl_policy,
+		.maxattr	= NETDEV_A_PAGE_POOL_STATS_INFO,
+		.flags		= GENL_CMD_CAP_DO,
+	},
+	{
+		.cmd	= NETDEV_CMD_PAGE_POOL_STATS_GET,
+		.dumpit	= netdev_nl_page_pool_stats_get_dumpit,
+		.flags	= GENL_CMD_CAP_DUMP,
+	},
+#endif /* CONFIG_PAGE_POOL_STATS */
 };
 
 static const struct genl_multicast_group netdev_nl_mcgrps[] = {
diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h
index 738097847100..649e4b46eccf 100644
--- a/net/core/netdev-genl-gen.h
+++ b/net/core/netdev-genl-gen.h
@@ -11,11 +11,18 @@
 
 #include <uapi/linux/netdev.h>
 
+/* Common nested types */
+extern const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFINDEX + 1];
+
 int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info);
 int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int netdev_nl_page_pool_get_doit(struct sk_buff *skb, struct genl_info *info);
 int netdev_nl_page_pool_get_dumpit(struct sk_buff *skb,
 				   struct netlink_callback *cb);
+int netdev_nl_page_pool_stats_get_doit(struct sk_buff *skb,
+				       struct genl_info *info);
+int netdev_nl_page_pool_stats_get_dumpit(struct sk_buff *skb,
+					 struct netlink_callback *cb);
 
 enum {
 	NETDEV_NLGRP_MGMT,
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 0f3f525c457a..af30c115769b 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -71,7 +71,7 @@ static const char pp_stats[][ETH_GSTRING_LEN] = {
  * is passed to this API which is filled in. The caller can then report
  * those stats to the user (perhaps via ethtool, debugfs, etc.).
  */
-bool page_pool_get_stats(struct page_pool *pool,
+bool page_pool_get_stats(const struct page_pool *pool,
 			 struct page_pool_stats *stats)
 {
 	int cpu = 0;
diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index d0f778f358fc..93dac22dff1a 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -5,6 +5,7 @@
 #include <linux/xarray.h>
 #include <net/net_debug.h>
 #include <net/page_pool/types.h>
+#include <net/page_pool/helpers.h>
 #include <net/sock.h>
 
 #include "page_pool_priv.h"
@@ -106,6 +107,108 @@ netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
 	return err;
 }
 
+static int
+page_pool_nl_stats_fill(struct sk_buff *rsp, const struct page_pool *pool,
+			const struct genl_info *info)
+{
+#ifdef CONFIG_PAGE_POOL_STATS
+	struct page_pool_stats stats = {};
+	struct nlattr *nest;
+	void *hdr;
+
+	if (!page_pool_get_stats(pool, &stats))
+		return 0;
+
+	hdr = genlmsg_iput(rsp, info);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	nest = nla_nest_start(rsp, NETDEV_A_PAGE_POOL_STATS_INFO);
+
+	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_ID, pool->user.id) ||
+	    (pool->slow.netdev->ifindex != LOOPBACK_IFINDEX &&
+	     nla_put_u32(rsp, NETDEV_A_PAGE_POOL_IFINDEX,
+			 pool->slow.netdev->ifindex)))
+		goto err_cancel_nest;
+
+	nla_nest_end(rsp, nest);
+
+	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_FAST,
+			 stats.alloc_stats.fast) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW,
+			 stats.alloc_stats.slow) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW_HIGH_ORDER,
+			 stats.alloc_stats.slow_high_order) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_EMPTY,
+			 stats.alloc_stats.empty) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_REFILL,
+			 stats.alloc_stats.refill) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_WAIVE,
+			 stats.alloc_stats.waive) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHED,
+			 stats.recycle_stats.cached) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHE_FULL,
+			 stats.recycle_stats.cache_full) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING,
+			 stats.recycle_stats.ring) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING_FULL,
+			 stats.recycle_stats.ring_full) ||
+	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RELEASED_REFCNT,
+			 stats.recycle_stats.released_refcnt))
+		goto err_cancel_msg;
+
+	genlmsg_end(rsp, hdr);
+
+	return 0;
+err_cancel_nest:
+	nla_nest_cancel(rsp, nest);
+err_cancel_msg:
+	genlmsg_cancel(rsp, hdr);
+	return -EMSGSIZE;
+#else
+	GENL_SET_ERR_MSG(info, "kernel built without CONFIG_PAGE_POOL_STATS");
+	return -EOPNOTSUPP;
+#endif
+}
+
+int netdev_nl_page_pool_stats_get_doit(struct sk_buff *skb,
+				       struct genl_info *info)
+{
+	struct nlattr *tb[ARRAY_SIZE(netdev_page_pool_info_nl_policy)];
+	struct nlattr *nest;
+	int err;
+	u32 id;
+
+	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_PAGE_POOL_STATS_INFO))
+		return -EINVAL;
+
+	nest = info->attrs[NETDEV_A_PAGE_POOL_STATS_INFO];
+	err = nla_parse_nested(tb, ARRAY_SIZE(tb) - 1, nest,
+			       netdev_page_pool_info_nl_policy,
+			       info->extack);
+	if (err)
+		return err;
+
+	if (NL_REQ_ATTR_CHECK(info->extack, nest, tb, NETDEV_A_PAGE_POOL_ID))
+		return -EINVAL;
+	if (tb[NETDEV_A_PAGE_POOL_IFINDEX]) {
+		NL_SET_ERR_MSG_ATTR(info->extack,
+				    tb[NETDEV_A_PAGE_POOL_IFINDEX],
+				    "selecting by ifindex not supported");
+		return -EINVAL;
+	}
+
+	id = nla_get_uint(tb[NETDEV_A_PAGE_POOL_ID]);
+
+	return netdev_nl_page_pool_get_do(info, id, page_pool_nl_stats_fill);
+}
+
+int netdev_nl_page_pool_stats_get_dumpit(struct sk_buff *skb,
+					 struct netlink_callback *cb)
+{
+	return netdev_nl_page_pool_get_dump(skb, cb, page_pool_nl_stats_fill);
+}
+
 static int
 page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
 		  const struct genl_info *info)
-- 
2.42.0

[PATCH net-next v2 14/15] net: page_pool: mute the periodic warning for visible page pools

[Jakub Kicinski]

Mute the periodic "stalled pool shutdown" warning if the page pool
is visible to user space. Rolling out a driver using page pools
to just a few hundred hosts at Meta surfaces applications which
fail to reap their broken sockets. Obviously it's best if the
applications are fixed, but we don't generally print warnings
for application resource leaks. Admins can now depend on the
netlink interface for getting page pool info to detect buggy
apps.

While at it throw in the ID of the pool into the message,
in rare cases (pools from destroyed netns) this will make
finding the pool with a debugger easier.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 net/core/page_pool.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index af30c115769b..29cfd5d955ac 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -897,18 +897,21 @@ static void page_pool_release_retry(struct work_struct *wq)
 {
 	struct delayed_work *dwq = to_delayed_work(wq);
 	struct page_pool *pool = container_of(dwq, typeof(*pool), release_dw);
+	void *netdev;
 	int inflight;
 
 	inflight = page_pool_release(pool);
 	if (!inflight)
 		return;
 
-	/* Periodic warning */
-	if (time_after_eq(jiffies, pool->defer_warn)) {
+	/* Periodic warning for page pools the user can't see */
+	netdev = READ_ONCE(pool->slow.netdev);
+	if (time_after_eq(jiffies, pool->defer_warn) &&
+	    (!netdev || netdev == NET_PTR_POISON)) {
 		int sec = (s32)((u32)jiffies - (u32)pool->defer_start) / HZ;
 
-		pr_warn("%s() stalled pool shutdown %d inflight %d sec\n",
-			__func__, inflight, sec);
+		pr_warn("%s() stalled pool shutdown: id %u, %d inflight %d sec\n",
+			__func__, pool->user.id, inflight, sec);
 		pool->defer_warn = jiffies + DEFER_WARN_INTERVAL;
 	}
 
-- 
2.42.0

[PATCH net-next v2 15/15] tools: ynl: add sample for getting page-pool information

[Jakub Kicinski]

Regenerate the tools/ code after netdev spec changes.

Add sample to query page-pool info in a concise fashion:

$ ./page-pool
    eth0[2]	page pools: 10 (zombies: 0)
		refs: 41984 bytes: 171966464 (refs: 0 bytes: 0)
		recycling: 90.3% (alloc: 656:397681 recycle: 89652:270201)

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 tools/include/uapi/linux/netdev.h     |  36 +++
 tools/net/ynl/generated/netdev-user.c | 419 ++++++++++++++++++++++++++
 tools/net/ynl/generated/netdev-user.h | 171 +++++++++++
 tools/net/ynl/lib/ynl.h               |   2 +-
 tools/net/ynl/samples/.gitignore      |   1 +
 tools/net/ynl/samples/Makefile        |   2 +-
 tools/net/ynl/samples/page-pool.c     | 147 +++++++++
 7 files changed, 776 insertions(+), 2 deletions(-)
 create mode 100644 tools/net/ynl/samples/page-pool.c

diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 2943a151d4f1..9d0a48717d1f 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -64,16 +64,52 @@ enum {
 	NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)
 };
 
+enum {
+	NETDEV_A_PAGE_POOL_ID = 1,
+	NETDEV_A_PAGE_POOL_IFINDEX,
+	NETDEV_A_PAGE_POOL_NAPI_ID,
+	NETDEV_A_PAGE_POOL_INFLIGHT,
+	NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
+	NETDEV_A_PAGE_POOL_DESTROYED,
+
+	__NETDEV_A_PAGE_POOL_MAX,
+	NETDEV_A_PAGE_POOL_MAX = (__NETDEV_A_PAGE_POOL_MAX - 1)
+};
+
+enum {
+	NETDEV_A_PAGE_POOL_STATS_INFO = 1,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_FAST = 8,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW_HIGH_ORDER,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_EMPTY,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_REFILL,
+	NETDEV_A_PAGE_POOL_STATS_ALLOC_WAIVE,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHED,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHE_FULL,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING_FULL,
+	NETDEV_A_PAGE_POOL_STATS_RECYCLE_RELEASED_REFCNT,
+
+	__NETDEV_A_PAGE_POOL_STATS_MAX,
+	NETDEV_A_PAGE_POOL_STATS_MAX = (__NETDEV_A_PAGE_POOL_STATS_MAX - 1)
+};
+
 enum {
 	NETDEV_CMD_DEV_GET = 1,
 	NETDEV_CMD_DEV_ADD_NTF,
 	NETDEV_CMD_DEV_DEL_NTF,
 	NETDEV_CMD_DEV_CHANGE_NTF,
+	NETDEV_CMD_PAGE_POOL_GET,
+	NETDEV_CMD_PAGE_POOL_ADD_NTF,
+	NETDEV_CMD_PAGE_POOL_DEL_NTF,
+	NETDEV_CMD_PAGE_POOL_CHANGE_NTF,
+	NETDEV_CMD_PAGE_POOL_STATS_GET,
 
 	__NETDEV_CMD_MAX,
 	NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
 };
 
 #define NETDEV_MCGRP_MGMT	"mgmt"
+#define NETDEV_MCGRP_PAGE_POOL	"page-pool"
 
 #endif /* _UAPI_LINUX_NETDEV_H */
diff --git a/tools/net/ynl/generated/netdev-user.c b/tools/net/ynl/generated/netdev-user.c
index b5ffe8cd1144..f9a000584493 100644
--- a/tools/net/ynl/generated/netdev-user.c
+++ b/tools/net/ynl/generated/netdev-user.c
@@ -18,6 +18,11 @@ static const char * const netdev_op_strmap[] = {
 	[NETDEV_CMD_DEV_ADD_NTF] = "dev-add-ntf",
 	[NETDEV_CMD_DEV_DEL_NTF] = "dev-del-ntf",
 	[NETDEV_CMD_DEV_CHANGE_NTF] = "dev-change-ntf",
+	[NETDEV_CMD_PAGE_POOL_GET] = "page-pool-get",
+	[NETDEV_CMD_PAGE_POOL_ADD_NTF] = "page-pool-add-ntf",
+	[NETDEV_CMD_PAGE_POOL_DEL_NTF] = "page-pool-del-ntf",
+	[NETDEV_CMD_PAGE_POOL_CHANGE_NTF] = "page-pool-change-ntf",
+	[NETDEV_CMD_PAGE_POOL_STATS_GET] = "page-pool-stats-get",
 };
 
 const char *netdev_op_str(int op)
@@ -59,6 +64,16 @@ const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value)
 }
 
 /* Policies */
+struct ynl_policy_attr netdev_page_pool_info_policy[NETDEV_A_PAGE_POOL_MAX + 1] = {
+	[NETDEV_A_PAGE_POOL_ID] = { .name = "id", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_IFINDEX] = { .name = "ifindex", .type = YNL_PT_U32, },
+};
+
+struct ynl_policy_nest netdev_page_pool_info_nest = {
+	.max_attr = NETDEV_A_PAGE_POOL_MAX,
+	.table = netdev_page_pool_info_policy,
+};
+
 struct ynl_policy_attr netdev_dev_policy[NETDEV_A_DEV_MAX + 1] = {
 	[NETDEV_A_DEV_IFINDEX] = { .name = "ifindex", .type = YNL_PT_U32, },
 	[NETDEV_A_DEV_PAD] = { .name = "pad", .type = YNL_PT_IGNORE, },
@@ -72,7 +87,85 @@ struct ynl_policy_nest netdev_dev_nest = {
 	.table = netdev_dev_policy,
 };
 
+struct ynl_policy_attr netdev_page_pool_policy[NETDEV_A_PAGE_POOL_MAX + 1] = {
+	[NETDEV_A_PAGE_POOL_ID] = { .name = "id", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_IFINDEX] = { .name = "ifindex", .type = YNL_PT_U32, },
+	[NETDEV_A_PAGE_POOL_NAPI_ID] = { .name = "napi-id", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_INFLIGHT] = { .name = "inflight", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_INFLIGHT_MEM] = { .name = "inflight-mem", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_DESTROYED] = { .name = "destroyed", .type = YNL_PT_UINT, },
+};
+
+struct ynl_policy_nest netdev_page_pool_nest = {
+	.max_attr = NETDEV_A_PAGE_POOL_MAX,
+	.table = netdev_page_pool_policy,
+};
+
+struct ynl_policy_attr netdev_page_pool_stats_policy[NETDEV_A_PAGE_POOL_STATS_MAX + 1] = {
+	[NETDEV_A_PAGE_POOL_STATS_INFO] = { .name = "info", .type = YNL_PT_NEST, .nest = &netdev_page_pool_info_nest, },
+	[NETDEV_A_PAGE_POOL_STATS_ALLOC_FAST] = { .name = "alloc-fast", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW] = { .name = "alloc-slow", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW_HIGH_ORDER] = { .name = "alloc-slow-high-order", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_ALLOC_EMPTY] = { .name = "alloc-empty", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_ALLOC_REFILL] = { .name = "alloc-refill", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_ALLOC_WAIVE] = { .name = "alloc-waive", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHED] = { .name = "recycle-cached", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHE_FULL] = { .name = "recycle-cache-full", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING] = { .name = "recycle-ring", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING_FULL] = { .name = "recycle-ring-full", .type = YNL_PT_UINT, },
+	[NETDEV_A_PAGE_POOL_STATS_RECYCLE_RELEASED_REFCNT] = { .name = "recycle-released-refcnt", .type = YNL_PT_UINT, },
+};
+
+struct ynl_policy_nest netdev_page_pool_stats_nest = {
+	.max_attr = NETDEV_A_PAGE_POOL_STATS_MAX,
+	.table = netdev_page_pool_stats_policy,
+};
+
 /* Common nested types */
+void netdev_page_pool_info_free(struct netdev_page_pool_info *obj)
+{
+}
+
+int netdev_page_pool_info_put(struct nlmsghdr *nlh, unsigned int attr_type,
+			      struct netdev_page_pool_info *obj)
+{
+	struct nlattr *nest;
+
+	nest = mnl_attr_nest_start(nlh, attr_type);
+	if (obj->_present.id)
+		mnl_attr_put_uint(nlh, NETDEV_A_PAGE_POOL_ID, obj->id);
+	if (obj->_present.ifindex)
+		mnl_attr_put_u32(nlh, NETDEV_A_PAGE_POOL_IFINDEX, obj->ifindex);
+	mnl_attr_nest_end(nlh, nest);
+
+	return 0;
+}
+
+int netdev_page_pool_info_parse(struct ynl_parse_arg *yarg,
+				const struct nlattr *nested)
+{
+	struct netdev_page_pool_info *dst = yarg->data;
+	const struct nlattr *attr;
+
+	mnl_attr_for_each_nested(attr, nested) {
+		unsigned int type = mnl_attr_get_type(attr);
+
+		if (type == NETDEV_A_PAGE_POOL_ID) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.id = 1;
+			dst->id = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_IFINDEX) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.ifindex = 1;
+			dst->ifindex = mnl_attr_get_u32(attr);
+		}
+	}
+
+	return 0;
+}
+
 /* ============== NETDEV_CMD_DEV_GET ============== */
 /* NETDEV_CMD_DEV_GET - do */
 void netdev_dev_get_req_free(struct netdev_dev_get_req *req)
@@ -197,6 +290,314 @@ void netdev_dev_get_ntf_free(struct netdev_dev_get_ntf *rsp)
 	free(rsp);
 }
 
+/* ============== NETDEV_CMD_PAGE_POOL_GET ============== */
+/* NETDEV_CMD_PAGE_POOL_GET - do */
+void netdev_page_pool_get_req_free(struct netdev_page_pool_get_req *req)
+{
+	free(req);
+}
+
+void netdev_page_pool_get_rsp_free(struct netdev_page_pool_get_rsp *rsp)
+{
+	free(rsp);
+}
+
+int netdev_page_pool_get_rsp_parse(const struct nlmsghdr *nlh, void *data)
+{
+	struct netdev_page_pool_get_rsp *dst;
+	struct ynl_parse_arg *yarg = data;
+	const struct nlattr *attr;
+
+	dst = yarg->data;
+
+	mnl_attr_for_each(attr, nlh, sizeof(struct genlmsghdr)) {
+		unsigned int type = mnl_attr_get_type(attr);
+
+		if (type == NETDEV_A_PAGE_POOL_ID) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.id = 1;
+			dst->id = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_IFINDEX) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.ifindex = 1;
+			dst->ifindex = mnl_attr_get_u32(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_NAPI_ID) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.napi_id = 1;
+			dst->napi_id = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_INFLIGHT) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.inflight = 1;
+			dst->inflight = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_INFLIGHT_MEM) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.inflight_mem = 1;
+			dst->inflight_mem = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_DESTROYED) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.destroyed = 1;
+			dst->destroyed = mnl_attr_get_uint(attr);
+		}
+	}
+
+	return MNL_CB_OK;
+}
+
+struct netdev_page_pool_get_rsp *
+netdev_page_pool_get(struct ynl_sock *ys, struct netdev_page_pool_get_req *req)
+{
+	struct ynl_req_state yrs = { .yarg = { .ys = ys, }, };
+	struct netdev_page_pool_get_rsp *rsp;
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NETDEV_CMD_PAGE_POOL_GET, 1);
+	ys->req_policy = &netdev_page_pool_nest;
+	yrs.yarg.rsp_policy = &netdev_page_pool_nest;
+
+	if (req->_present.id)
+		mnl_attr_put_uint(nlh, NETDEV_A_PAGE_POOL_ID, req->id);
+
+	rsp = calloc(1, sizeof(*rsp));
+	yrs.yarg.data = rsp;
+	yrs.cb = netdev_page_pool_get_rsp_parse;
+	yrs.rsp_cmd = NETDEV_CMD_PAGE_POOL_GET;
+
+	err = ynl_exec(ys, nlh, &yrs);
+	if (err < 0)
+		goto err_free;
+
+	return rsp;
+
+err_free:
+	netdev_page_pool_get_rsp_free(rsp);
+	return NULL;
+}
+
+/* NETDEV_CMD_PAGE_POOL_GET - dump */
+void netdev_page_pool_get_list_free(struct netdev_page_pool_get_list *rsp)
+{
+	struct netdev_page_pool_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		free(rsp);
+	}
+}
+
+struct netdev_page_pool_get_list *
+netdev_page_pool_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct netdev_page_pool_get_list);
+	yds.cb = netdev_page_pool_get_rsp_parse;
+	yds.rsp_cmd = NETDEV_CMD_PAGE_POOL_GET;
+	yds.rsp_policy = &netdev_page_pool_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NETDEV_CMD_PAGE_POOL_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	netdev_page_pool_get_list_free(yds.first);
+	return NULL;
+}
+
+/* NETDEV_CMD_PAGE_POOL_GET - notify */
+void netdev_page_pool_get_ntf_free(struct netdev_page_pool_get_ntf *rsp)
+{
+	free(rsp);
+}
+
+/* ============== NETDEV_CMD_PAGE_POOL_STATS_GET ============== */
+/* NETDEV_CMD_PAGE_POOL_STATS_GET - do */
+void
+netdev_page_pool_stats_get_req_free(struct netdev_page_pool_stats_get_req *req)
+{
+	netdev_page_pool_info_free(&req->info);
+	free(req);
+}
+
+void
+netdev_page_pool_stats_get_rsp_free(struct netdev_page_pool_stats_get_rsp *rsp)
+{
+	netdev_page_pool_info_free(&rsp->info);
+	free(rsp);
+}
+
+int netdev_page_pool_stats_get_rsp_parse(const struct nlmsghdr *nlh,
+					 void *data)
+{
+	struct netdev_page_pool_stats_get_rsp *dst;
+	struct ynl_parse_arg *yarg = data;
+	const struct nlattr *attr;
+	struct ynl_parse_arg parg;
+
+	dst = yarg->data;
+	parg.ys = yarg->ys;
+
+	mnl_attr_for_each(attr, nlh, sizeof(struct genlmsghdr)) {
+		unsigned int type = mnl_attr_get_type(attr);
+
+		if (type == NETDEV_A_PAGE_POOL_STATS_INFO) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.info = 1;
+
+			parg.rsp_policy = &netdev_page_pool_info_nest;
+			parg.data = &dst->info;
+			if (netdev_page_pool_info_parse(&parg, attr))
+				return MNL_CB_ERROR;
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_ALLOC_FAST) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.alloc_fast = 1;
+			dst->alloc_fast = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.alloc_slow = 1;
+			dst->alloc_slow = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW_HIGH_ORDER) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.alloc_slow_high_order = 1;
+			dst->alloc_slow_high_order = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_ALLOC_EMPTY) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.alloc_empty = 1;
+			dst->alloc_empty = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_ALLOC_REFILL) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.alloc_refill = 1;
+			dst->alloc_refill = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_ALLOC_WAIVE) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.alloc_waive = 1;
+			dst->alloc_waive = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHED) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.recycle_cached = 1;
+			dst->recycle_cached = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHE_FULL) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.recycle_cache_full = 1;
+			dst->recycle_cache_full = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.recycle_ring = 1;
+			dst->recycle_ring = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING_FULL) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.recycle_ring_full = 1;
+			dst->recycle_ring_full = mnl_attr_get_uint(attr);
+		} else if (type == NETDEV_A_PAGE_POOL_STATS_RECYCLE_RELEASED_REFCNT) {
+			if (ynl_attr_validate(yarg, attr))
+				return MNL_CB_ERROR;
+			dst->_present.recycle_released_refcnt = 1;
+			dst->recycle_released_refcnt = mnl_attr_get_uint(attr);
+		}
+	}
+
+	return MNL_CB_OK;
+}
+
+struct netdev_page_pool_stats_get_rsp *
+netdev_page_pool_stats_get(struct ynl_sock *ys,
+			   struct netdev_page_pool_stats_get_req *req)
+{
+	struct ynl_req_state yrs = { .yarg = { .ys = ys, }, };
+	struct netdev_page_pool_stats_get_rsp *rsp;
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, NETDEV_CMD_PAGE_POOL_STATS_GET, 1);
+	ys->req_policy = &netdev_page_pool_stats_nest;
+	yrs.yarg.rsp_policy = &netdev_page_pool_stats_nest;
+
+	if (req->_present.info)
+		netdev_page_pool_info_put(nlh, NETDEV_A_PAGE_POOL_STATS_INFO, &req->info);
+
+	rsp = calloc(1, sizeof(*rsp));
+	yrs.yarg.data = rsp;
+	yrs.cb = netdev_page_pool_stats_get_rsp_parse;
+	yrs.rsp_cmd = NETDEV_CMD_PAGE_POOL_STATS_GET;
+
+	err = ynl_exec(ys, nlh, &yrs);
+	if (err < 0)
+		goto err_free;
+
+	return rsp;
+
+err_free:
+	netdev_page_pool_stats_get_rsp_free(rsp);
+	return NULL;
+}
+
+/* NETDEV_CMD_PAGE_POOL_STATS_GET - dump */
+void
+netdev_page_pool_stats_get_list_free(struct netdev_page_pool_stats_get_list *rsp)
+{
+	struct netdev_page_pool_stats_get_list *next = rsp;
+
+	while ((void *)next != YNL_LIST_END) {
+		rsp = next;
+		next = rsp->next;
+
+		netdev_page_pool_info_free(&rsp->obj.info);
+		free(rsp);
+	}
+}
+
+struct netdev_page_pool_stats_get_list *
+netdev_page_pool_stats_get_dump(struct ynl_sock *ys)
+{
+	struct ynl_dump_state yds = {};
+	struct nlmsghdr *nlh;
+	int err;
+
+	yds.ys = ys;
+	yds.alloc_sz = sizeof(struct netdev_page_pool_stats_get_list);
+	yds.cb = netdev_page_pool_stats_get_rsp_parse;
+	yds.rsp_cmd = NETDEV_CMD_PAGE_POOL_STATS_GET;
+	yds.rsp_policy = &netdev_page_pool_stats_nest;
+
+	nlh = ynl_gemsg_start_dump(ys, ys->family_id, NETDEV_CMD_PAGE_POOL_STATS_GET, 1);
+
+	err = ynl_exec_dump(ys, nlh, &yds);
+	if (err < 0)
+		goto free_list;
+
+	return yds.first;
+
+free_list:
+	netdev_page_pool_stats_get_list_free(yds.first);
+	return NULL;
+}
+
 static const struct ynl_ntf_info netdev_ntf_info[] =  {
 	[NETDEV_CMD_DEV_ADD_NTF] =  {
 		.alloc_sz	= sizeof(struct netdev_dev_get_ntf),
@@ -216,6 +617,24 @@ static const struct ynl_ntf_info netdev_ntf_info[] =  {
 		.policy		= &netdev_dev_nest,
 		.free		= (void *)netdev_dev_get_ntf_free,
 	},
+	[NETDEV_CMD_PAGE_POOL_ADD_NTF] =  {
+		.alloc_sz	= sizeof(struct netdev_page_pool_get_ntf),
+		.cb		= netdev_page_pool_get_rsp_parse,
+		.policy		= &netdev_page_pool_nest,
+		.free		= (void *)netdev_page_pool_get_ntf_free,
+	},
+	[NETDEV_CMD_PAGE_POOL_DEL_NTF] =  {
+		.alloc_sz	= sizeof(struct netdev_page_pool_get_ntf),
+		.cb		= netdev_page_pool_get_rsp_parse,
+		.policy		= &netdev_page_pool_nest,
+		.free		= (void *)netdev_page_pool_get_ntf_free,
+	},
+	[NETDEV_CMD_PAGE_POOL_CHANGE_NTF] =  {
+		.alloc_sz	= sizeof(struct netdev_page_pool_get_ntf),
+		.cb		= netdev_page_pool_get_rsp_parse,
+		.policy		= &netdev_page_pool_nest,
+		.free		= (void *)netdev_page_pool_get_ntf_free,
+	},
 };
 
 const struct ynl_family ynl_netdev_family =  {
diff --git a/tools/net/ynl/generated/netdev-user.h b/tools/net/ynl/generated/netdev-user.h
index 4fafac879df3..f27ad84fe020 100644
--- a/tools/net/ynl/generated/netdev-user.h
+++ b/tools/net/ynl/generated/netdev-user.h
@@ -21,6 +21,16 @@ const char *netdev_xdp_act_str(enum netdev_xdp_act value);
 const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value);
 
 /* Common nested types */
+struct netdev_page_pool_info {
+	struct {
+		__u32 id:1;
+		__u32 ifindex:1;
+	} _present;
+
+	__u64 id;
+	__u32 ifindex;
+};
+
 /* ============== NETDEV_CMD_DEV_GET ============== */
 /* NETDEV_CMD_DEV_GET - do */
 struct netdev_dev_get_req {
@@ -87,4 +97,165 @@ struct netdev_dev_get_ntf {
 
 void netdev_dev_get_ntf_free(struct netdev_dev_get_ntf *rsp);
 
+/* ============== NETDEV_CMD_PAGE_POOL_GET ============== */
+/* NETDEV_CMD_PAGE_POOL_GET - do */
+struct netdev_page_pool_get_req {
+	struct {
+		__u32 id:1;
+	} _present;
+
+	__u64 id;
+};
+
+static inline struct netdev_page_pool_get_req *
+netdev_page_pool_get_req_alloc(void)
+{
+	return calloc(1, sizeof(struct netdev_page_pool_get_req));
+}
+void netdev_page_pool_get_req_free(struct netdev_page_pool_get_req *req);
+
+static inline void
+netdev_page_pool_get_req_set_id(struct netdev_page_pool_get_req *req, __u64 id)
+{
+	req->_present.id = 1;
+	req->id = id;
+}
+
+struct netdev_page_pool_get_rsp {
+	struct {
+		__u32 id:1;
+		__u32 ifindex:1;
+		__u32 napi_id:1;
+		__u32 inflight:1;
+		__u32 inflight_mem:1;
+		__u32 destroyed:1;
+	} _present;
+
+	__u64 id;
+	__u32 ifindex;
+	__u64 napi_id;
+	__u64 inflight;
+	__u64 inflight_mem;
+	__u64 destroyed;
+};
+
+void netdev_page_pool_get_rsp_free(struct netdev_page_pool_get_rsp *rsp);
+
+/*
+ * Get / dump information about Page Pools.
+(Only Page Pools associated with a net_device can be listed.)
+
+ */
+struct netdev_page_pool_get_rsp *
+netdev_page_pool_get(struct ynl_sock *ys, struct netdev_page_pool_get_req *req);
+
+/* NETDEV_CMD_PAGE_POOL_GET - dump */
+struct netdev_page_pool_get_list {
+	struct netdev_page_pool_get_list *next;
+	struct netdev_page_pool_get_rsp obj __attribute__((aligned(8)));
+};
+
+void netdev_page_pool_get_list_free(struct netdev_page_pool_get_list *rsp);
+
+struct netdev_page_pool_get_list *
+netdev_page_pool_get_dump(struct ynl_sock *ys);
+
+/* NETDEV_CMD_PAGE_POOL_GET - notify */
+struct netdev_page_pool_get_ntf {
+	__u16 family;
+	__u8 cmd;
+	struct ynl_ntf_base_type *next;
+	void (*free)(struct netdev_page_pool_get_ntf *ntf);
+	struct netdev_page_pool_get_rsp obj __attribute__((aligned(8)));
+};
+
+void netdev_page_pool_get_ntf_free(struct netdev_page_pool_get_ntf *rsp);
+
+/* ============== NETDEV_CMD_PAGE_POOL_STATS_GET ============== */
+/* NETDEV_CMD_PAGE_POOL_STATS_GET - do */
+struct netdev_page_pool_stats_get_req {
+	struct {
+		__u32 info:1;
+	} _present;
+
+	struct netdev_page_pool_info info;
+};
+
+static inline struct netdev_page_pool_stats_get_req *
+netdev_page_pool_stats_get_req_alloc(void)
+{
+	return calloc(1, sizeof(struct netdev_page_pool_stats_get_req));
+}
+void
+netdev_page_pool_stats_get_req_free(struct netdev_page_pool_stats_get_req *req);
+
+static inline void
+netdev_page_pool_stats_get_req_set_info_id(struct netdev_page_pool_stats_get_req *req,
+					   __u64 id)
+{
+	req->_present.info = 1;
+	req->info._present.id = 1;
+	req->info.id = id;
+}
+static inline void
+netdev_page_pool_stats_get_req_set_info_ifindex(struct netdev_page_pool_stats_get_req *req,
+						__u32 ifindex)
+{
+	req->_present.info = 1;
+	req->info._present.ifindex = 1;
+	req->info.ifindex = ifindex;
+}
+
+struct netdev_page_pool_stats_get_rsp {
+	struct {
+		__u32 info:1;
+		__u32 alloc_fast:1;
+		__u32 alloc_slow:1;
+		__u32 alloc_slow_high_order:1;
+		__u32 alloc_empty:1;
+		__u32 alloc_refill:1;
+		__u32 alloc_waive:1;
+		__u32 recycle_cached:1;
+		__u32 recycle_cache_full:1;
+		__u32 recycle_ring:1;
+		__u32 recycle_ring_full:1;
+		__u32 recycle_released_refcnt:1;
+	} _present;
+
+	struct netdev_page_pool_info info;
+	__u64 alloc_fast;
+	__u64 alloc_slow;
+	__u64 alloc_slow_high_order;
+	__u64 alloc_empty;
+	__u64 alloc_refill;
+	__u64 alloc_waive;
+	__u64 recycle_cached;
+	__u64 recycle_cache_full;
+	__u64 recycle_ring;
+	__u64 recycle_ring_full;
+	__u64 recycle_released_refcnt;
+};
+
+void
+netdev_page_pool_stats_get_rsp_free(struct netdev_page_pool_stats_get_rsp *rsp);
+
+/*
+ * Get page pool statistics.
+ */
+struct netdev_page_pool_stats_get_rsp *
+netdev_page_pool_stats_get(struct ynl_sock *ys,
+			   struct netdev_page_pool_stats_get_req *req);
+
+/* NETDEV_CMD_PAGE_POOL_STATS_GET - dump */
+struct netdev_page_pool_stats_get_list {
+	struct netdev_page_pool_stats_get_list *next;
+	struct netdev_page_pool_stats_get_rsp obj __attribute__((aligned(8)));
+};
+
+void
+netdev_page_pool_stats_get_list_free(struct netdev_page_pool_stats_get_list *rsp);
+
+struct netdev_page_pool_stats_get_list *
+netdev_page_pool_stats_get_dump(struct ynl_sock *ys);
+
 #endif /* _LINUX_NETDEV_GEN_H */
diff --git a/tools/net/ynl/lib/ynl.h b/tools/net/ynl/lib/ynl.h
index e974378e3b8c..075d868f3b57 100644
--- a/tools/net/ynl/lib/ynl.h
+++ b/tools/net/ynl/lib/ynl.h
@@ -239,7 +239,7 @@ int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg);
 #ifndef MNL_HAS_AUTO_SCALARS
 static inline uint64_t mnl_attr_get_uint(const struct nlattr *attr)
 {
-	if (mnl_attr_get_len(attr) == 4)
+	if (mnl_attr_get_payload_len(attr) == 4)
 		return mnl_attr_get_u32(attr);
 	return mnl_attr_get_u64(attr);
 }
diff --git a/tools/net/ynl/samples/.gitignore b/tools/net/ynl/samples/.gitignore
index 2aae60c4829f..49637b26c482 100644
--- a/tools/net/ynl/samples/.gitignore
+++ b/tools/net/ynl/samples/.gitignore
@@ -1,3 +1,4 @@
 ethtool
 devlink
 netdev
+page-pool
\ No newline at end of file
diff --git a/tools/net/ynl/samples/Makefile b/tools/net/ynl/samples/Makefile
index 3dbb106e87d9..1afefc266b7a 100644
--- a/tools/net/ynl/samples/Makefile
+++ b/tools/net/ynl/samples/Makefile
@@ -18,7 +18,7 @@ include $(wildcard *.d)
 
 all: $(BINS)
 
-$(BINS): ../lib/ynl.a ../generated/protos.a
+$(BINS): ../lib/ynl.a ../generated/protos.a $(SRCS)
 	@echo -e '\tCC sample $@'
 	@$(COMPILE.c) $(CFLAGS_$@) $@.c -o $@.o
 	@$(LINK.c) $@.o -o $@  $(LDLIBS)
diff --git a/tools/net/ynl/samples/page-pool.c b/tools/net/ynl/samples/page-pool.c
new file mode 100644
index 000000000000..18d359713469
--- /dev/null
+++ b/tools/net/ynl/samples/page-pool.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <string.h>
+
+#include <ynl.h>
+
+#include <net/if.h>
+
+#include "netdev-user.h"
+
+struct stat {
+	unsigned int ifc;
+
+	struct {
+		unsigned int cnt;
+		size_t refs, bytes;
+	} live[2];
+
+	size_t alloc_slow, alloc_fast, recycle_ring, recycle_cache;
+};
+
+struct stats_array {
+	unsigned int i, max;
+	struct stat *s;
+};
+
+static struct stat *find_ifc(struct stats_array *a, unsigned int ifindex)
+{
+	unsigned int i;
+
+	for (i = 0; i < a->i; i++) {
+		if (a->s[i].ifc == ifindex)
+			return &a->s[i];
+	}
+
+	a->i++;
+	if (a->i == a->max) {
+		a->max *= 2;
+		a->s = reallocarray(a->s, a->max, sizeof(*a->s));
+	}
+	a->s[i].ifc = ifindex;
+	return &a->s[i];
+}
+
+static void count(struct stat *s, unsigned int l,
+		  struct netdev_page_pool_get_rsp *pp)
+{
+	s->live[l].cnt++;
+	if (pp->_present.inflight)
+		s->live[l].refs += pp->inflight;
+	if (pp->_present.inflight_mem)
+		s->live[l].bytes += pp->inflight_mem;
+}
+
+int main(int argc, char **argv)
+{
+	struct netdev_page_pool_stats_get_list *pp_stats;
+	struct netdev_page_pool_get_list *pools;
+	struct stats_array a = {};
+	struct ynl_error yerr;
+	struct ynl_sock *ys;
+
+	ys = ynl_sock_create(&ynl_netdev_family, &yerr);
+	if (!ys) {
+		fprintf(stderr, "YNL: %s\n", yerr.msg);
+		return 1;
+	}
+
+	a.max = 128;
+	a.s = calloc(a.max, sizeof(*a.s));
+	if (!a.s)
+		goto err_close;
+
+	pools = netdev_page_pool_get_dump(ys);
+	if (!pools)
+		goto err_free;
+
+	ynl_dump_foreach(pools, pp) {
+		struct stat *s = find_ifc(&a, pp->ifindex);
+
+		count(s, 1, pp);
+		if (pp->_present.destroyed)
+			count(s, 0, pp);
+	}
+	netdev_page_pool_get_list_free(pools);
+
+	pp_stats = netdev_page_pool_stats_get_dump(ys);
+	if (!pp_stats)
+		goto err_free;
+
+	ynl_dump_foreach(pp_stats, pp) {
+		struct stat *s = find_ifc(&a, pp->info.ifindex);
+
+		if (pp->_present.alloc_fast)
+			s->alloc_fast += pp->alloc_fast;
+		if (pp->_present.alloc_slow)
+			s->alloc_slow += pp->alloc_slow;
+		if (pp->_present.recycle_ring)
+			s->recycle_ring += pp->recycle_ring;
+		if (pp->_present.recycle_cached)
+			s->recycle_cache += pp->recycle_cached;
+	}
+	netdev_page_pool_stats_get_list_free(pp_stats);
+
+	for (unsigned int i = 0; i < a.i; i++) {
+		char ifname[IF_NAMESIZE];
+		struct stat *s = &a.s[i];
+		const char *name;
+		double recycle;
+
+		if (!s->ifc) {
+			name = "<orphan>\t";
+		} else {
+			name = if_indextoname(s->ifc, ifname);
+			if (name)
+				printf("%8s", name);
+			printf("[%d]\t", s->ifc);
+		}
+
+		printf("page pools: %u (zombies: %u)\n",
+		       s->live[1].cnt, s->live[0].cnt);
+		printf("\t\trefs: %zu bytes: %zu (refs: %zu bytes: %zu)\n",
+		       s->live[1].refs, s->live[1].bytes,
+		       s->live[0].refs, s->live[0].bytes);
+
+		/* We don't know how many pages are sitting in cache and ring
+		 * so we will under-count the recycling rate a bit.
+		 */
+		recycle = (double)(s->recycle_ring + s->recycle_cache) /
+			(s->alloc_fast + s->alloc_slow) * 100;
+		printf("\t\trecycling: %.1lf%% (alloc: %zu:%zu recycle: %zu:%zu)\n",
+		       recycle, s->alloc_slow, s->alloc_fast,
+		       s->recycle_ring, s->recycle_cache);
+	}
+
+	ynl_sock_destroy(ys);
+	return 0;
+
+err_free:
+	free(a.s);
+err_close:
+	fprintf(stderr, "YNL: %s\n", ys->err.msg);
+	ynl_sock_destroy(ys);
+	return 2;
+}
-- 
2.42.0

Re: [PATCH net-next v2 00/15] net: page_pool: add netlink-based introspection

[Jakub Kicinski]

On Mon, 20 Nov 2023 16:00:33 -0800 Jakub Kicinski wrote:
>   net: page_pool: split the page_pool_params into fast and slow
>   net: page_pool: avoid touching slow on the fastpath

To relieve some of the pain and suffering this series causes to our
build tester I'm going to apply the first 2 patches already. I hope
that's fine. They are pretty stand-alone and have broad acks/review
tags.

Re: [PATCH net-next v2 00/15] net: page_pool: add netlink-based introspection

[Jesper Dangaard Brouer]

On 11/22/23 02:31, Jakub Kicinski wrote:
> On Mon, 20 Nov 2023 16:00:33 -0800 Jakub Kicinski wrote:
>>    net: page_pool: split the page_pool_params into fast and slow
>>    net: page_pool: avoid touching slow on the fastpath
> 
> To relieve some of the pain and suffering this series causes to our
> build tester I'm going to apply the first 2 patches already. I hope
> that's fine. They are pretty stand-alone and have broad acks/review
> tags.

Fine by me to apply the first 2 patches. Thanks for communicating this 
as I did get confused seeing patchwork-bot reporting this was applied 
and seeing a V3 on the list.

Keep up the good work. Overall I like this netlink-based introspection.
I'll try to get some opinions from Cloudflare people how this can be
integrated into existing monitoring systems.

--Jesper

Re: [PATCH net-next v2 00/15] net: page_pool: add netlink-based introspection

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 20 Nov 2023 16:00:33 -0800 you wrote:
> We recently started to deploy newer kernels / drivers at Meta,
> making significant use of page pools for the first time.
> We immediately run into page pool leaks both real and false positive
> warnings. As Eric pointed out/predicted there's no guarantee that
> applications will read / close their sockets so a page pool page
> may be stuck in a socket (but not leaked) forever. This happens
> a lot in our fleet. Most of these are obviously due to application
> bugs but we should not be printing kernel warnings due to minor
> application resource leaks.
> 
> [...]

Here is the summary with links:
  - [net-next,v2,01/15] net: page_pool: split the page_pool_params into fast and slow
    https://git.kernel.org/netdev/net-next/c/5027ec19f104
  - [net-next,v2,02/15] net: page_pool: avoid touching slow on the fastpath
    https://git.kernel.org/netdev/net-next/c/2da0cac1e949
  - [net-next,v2,03/15] net: page_pool: factor out uninit
    (no matching commit)
  - [net-next,v2,04/15] net: page_pool: id the page pools
    (no matching commit)
  - [net-next,v2,05/15] net: page_pool: record pools per netdev
    (no matching commit)
  - [net-next,v2,06/15] net: page_pool: stash the NAPI ID for easier access
    (no matching commit)
  - [net-next,v2,07/15] eth: link netdev to page_pools in drivers
    (no matching commit)
  - [net-next,v2,08/15] net: page_pool: add nlspec for basic access to page pools
    (no matching commit)
  - [net-next,v2,09/15] net: page_pool: implement GET in the netlink API
    (no matching commit)
  - [net-next,v2,10/15] net: page_pool: add netlink notifications for state changes
    (no matching commit)
  - [net-next,v2,11/15] net: page_pool: report amount of memory held by page pools
    (no matching commit)
  - [net-next,v2,12/15] net: page_pool: report when page pool was destroyed
    (no matching commit)
  - [net-next,v2,13/15] net: page_pool: expose page pool stats via netlink
    (no matching commit)
  - [net-next,v2,14/15] net: page_pool: mute the periodic warning for visible page pools
    (no matching commit)
  - [net-next,v2,15/15] tools: ynl: add sample for getting page-pool information
    (no matching commit)

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html