From 32c28f7e413981c7dd4a3ad9bbb1151e4b654261 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 18 Jun 2019 15:06:03 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/trace/events/page_pool.h | 87 ++++++++++++++++++++++++++++++++ net/core/net-traces.c | 4 ++ net/core/page_pool.c | 9 +++- 3 files changed, 99 insertions(+), 1 deletion(-) create mode 100644 include/trace/events/page_pool.h 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 +#include + +#include + +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 diff --git a/net/core/net-traces.c b/net/core/net-traces.c index 470b179d599e..283ddb2dbc7d 100644 --- a/net/core/net-traces.c +++ b/net/core/net-traces.c @@ -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 +#endif + #include EXPORT_TRACEPOINT_SYMBOL_GPL(neigh_update); EXPORT_TRACEPOINT_SYMBOL_GPL(neigh_update_done); diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 42c3b0a5a259..f55ab055d543 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -4,6 +4,7 @@ * Author: Jesper Dangaard Brouer * Copyright (C) 2016 Red Hat, Inc. */ + #include #include #include @@ -14,6 +15,8 @@ #include #include /* for __put_page() */ +#include + 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 */