Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 32c28f7e authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by David S. Miller
Browse files

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: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f033b688

include/trace/events/page_pool.h

0 → 100644
+87 −0
Original line number Diff line number Diff line 
/* 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>

net/core/net-traces.c

+4 −0
Original line number Diff line number Diff line
@@ -43,6 +43,10 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(fdb_delete); 
EXPORT_TRACEPOINT_SYMBOL_GPL(br_fdb_update);

#endif



#if IS_ENABLED(CONFIG_PAGE_POOL)

#include <trace/events/page_pool.h>

#endif



#include <trace/events/neigh.h>

EXPORT_TRACEPOINT_SYMBOL_GPL(neigh_update);

EXPORT_TRACEPOINT_SYMBOL_GPL(neigh_update_done);

net/core/page_pool.c

+8 −1
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 *	Author:	Jesper Dangaard Brouer <netoptimizer@brouer.com>

 *	Copyright (C) 2016 Red Hat, Inc.

 */



#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/slab.h>
@@ -14,6 +15,8 @@ 
#include <linux/page-flags.h>

#include <linux/mm.h> /* for __put_page() */



#include <trace/events/page_pool.h>



static int page_pool_init(struct page_pool *pool,

			  const struct page_pool_params *params)

{
@@ -156,6 +159,8 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, 
	/* Track how many pages are held 'in-flight' */

	pool->pages_state_hold_cnt++;



	trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt);



	/* When page just alloc'ed is should/must have refcnt 1. */

	return page;

}
@@ -191,7 +196,7 @@ static s32 page_pool_inflight(struct page_pool *pool) 


	distance = _distance(hold_cnt, release_cnt);



	/* TODO: Add tracepoint here */

	trace_page_pool_inflight(pool, distance, hold_cnt, release_cnt);

	return distance;

}
@@ -222,6 +227,8 @@ static void __page_pool_clean_page(struct page_pool *pool, 
	page->dma_addr = 0;

skip_dma_unmap:

	atomic_inc(&pool->pages_state_release_cnt);

	trace_page_pool_state_release(pool, page,

			      atomic_read(&pool->pages_state_release_cnt));

}



/* unmap the page and clean our state */