page_pool: add tracepoints for page_pool with details need by XDP

The xdp tracepoints for mem id disconnect don't carry information about, why
it was not safe_to_remove.  The tracepoint page_pool:page_pool_inflight in
this patch can be used for extract this info for further debugging.

This patchset also adds tracepoint for the pages_state_* release/hold
transitions, including a pointer to the page.  This can be used for stats
about in-flight pages, or used to debug page leakage via keeping track of
page pointer and combining this with kprobe for __put_page().

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 87 insertions, 0 deletions

diff --git a/include/trace/events/page_pool.h b/include/trace/events/page_pool.h
new file mode 100644
index 000000000000..47b5ee880aa9
--- /dev/null
+++ b/include/trace/events/page_pool.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM page_pool
+
+#if !defined(_TRACE_PAGE_POOL_H) || defined(TRACE_HEADER_MULTI_READ)
+#define      _TRACE_PAGE_POOL_H
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+#include <net/page_pool.h>
+
+TRACE_EVENT(page_pool_inflight,
+
+	TP_PROTO(const struct page_pool *pool,
+		 s32 inflight, u32 hold, u32 release),
+
+	TP_ARGS(pool, inflight, hold, release),
+
+	TP_STRUCT__entry(
+		__field(const struct page_pool *, pool)
+		__field(s32,	inflight)
+		__field(u32,	hold)
+		__field(u32,	release)
+	),
+
+	TP_fast_assign(
+		__entry->pool		= pool;
+		__entry->inflight	= inflight;
+		__entry->hold		= hold;
+		__entry->release	= release;
+	),
+
+	TP_printk("page_pool=%p inflight=%d hold=%u release=%u",
+	  __entry->pool, __entry->inflight, __entry->hold, __entry->release)
+);
+
+TRACE_EVENT(page_pool_state_release,
+
+	TP_PROTO(const struct page_pool *pool,
+		 const struct page *page, u32 release),
+
+	TP_ARGS(pool, page, release),
+
+	TP_STRUCT__entry(
+		__field(const struct page_pool *,	pool)
+		__field(const struct page *,		page)
+		__field(u32,				release)
+	),
+
+	TP_fast_assign(
+		__entry->pool		= pool;
+		__entry->page		= page;
+		__entry->release	= release;
+	),
+
+	TP_printk("page_pool=%p page=%p release=%u",
+		  __entry->pool, __entry->page, __entry->release)
+);
+
+TRACE_EVENT(page_pool_state_hold,
+
+	TP_PROTO(const struct page_pool *pool,
+		 const struct page *page, u32 hold),
+
+	TP_ARGS(pool, page, hold),
+
+	TP_STRUCT__entry(
+		__field(const struct page_pool *,	pool)
+		__field(const struct page *,		page)
+		__field(u32,				hold)
+	),
+
+	TP_fast_assign(
+		__entry->pool	= pool;
+		__entry->page	= page;
+		__entry->hold	= hold;
+	),
+
+	TP_printk("page_pool=%p page=%p hold=%u",
+		  __entry->pool, __entry->page, __entry->hold)
+);
+
+#endif /* _TRACE_PAGE_POOL_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>