diff options
| -rw-r--r-- | crypto/async_tx/async_pq.c | 2 | ||||
| -rw-r--r-- | include/linux/page_ref.h | 98 | ||||
| -rw-r--r-- | include/trace/events/page_ref.h | 134 | ||||
| -rw-r--r-- | mm/Kconfig.debug | 13 | ||||
| -rw-r--r-- | mm/Makefile | 1 | ||||
| -rw-r--r-- | mm/debug_page_ref.c | 54 |
6 files changed, 296 insertions, 6 deletions
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c index c0748bbd4c08..08b3ac68952b 100644 --- a/crypto/async_tx/async_pq.c +++ b/crypto/async_tx/async_pq.c @@ -444,7 +444,7 @@ static int __init async_pq_init(void) static void __exit async_pq_exit(void) { - put_page(pq_scribble_page); + __free_page(pq_scribble_page); } module_init(async_pq_init); diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h index 30f5817f6b8e..e596d5d9540e 100644 --- a/include/linux/page_ref.h +++ b/include/linux/page_ref.h @@ -4,6 +4,62 @@ #include <linux/atomic.h> #include <linux/mm_types.h> #include <linux/page-flags.h> +#include <linux/tracepoint-defs.h> + +extern struct tracepoint __tracepoint_page_ref_set; +extern struct tracepoint __tracepoint_page_ref_mod; +extern struct tracepoint __tracepoint_page_ref_mod_and_test; +extern struct tracepoint __tracepoint_page_ref_mod_and_return; +extern struct tracepoint __tracepoint_page_ref_mod_unless; +extern struct tracepoint __tracepoint_page_ref_freeze; +extern struct tracepoint __tracepoint_page_ref_unfreeze; + +#ifdef CONFIG_DEBUG_PAGE_REF + +/* + * Ideally we would want to use the trace_<tracepoint>_enabled() helper + * functions. But due to include header file issues, that is not + * feasible. Instead we have to open code the static key functions. + * + * See trace_##name##_enabled(void) in include/linux/tracepoint.h + */ +#define page_ref_tracepoint_active(t) static_key_false(&(t).key) + +extern void __page_ref_set(struct page *page, int v); +extern void __page_ref_mod(struct page *page, int v); +extern void __page_ref_mod_and_test(struct page *page, int v, int ret); +extern void __page_ref_mod_and_return(struct page *page, int v, int ret); +extern void __page_ref_mod_unless(struct page *page, int v, int u); +extern void __page_ref_freeze(struct page *page, int v, int ret); +extern void __page_ref_unfreeze(struct page *page, int v); + +#else + +#define page_ref_tracepoint_active(t) false + +static inline void __page_ref_set(struct page *page, int v) +{ +} +static inline void __page_ref_mod(struct page *page, int v) +{ +} +static inline void __page_ref_mod_and_test(struct page *page, int v, int ret) +{ +} +static inline void __page_ref_mod_and_return(struct page *page, int v, int ret) +{ +} +static inline void __page_ref_mod_unless(struct page *page, int v, int u) +{ +} +static inline void __page_ref_freeze(struct page *page, int v, int ret) +{ +} +static inline void __page_ref_unfreeze(struct page *page, int v) +{ +} + +#endif static inline int page_ref_count(struct page *page) { @@ -18,6 +74,8 @@ static inline int page_count(struct page *page) static inline void set_page_count(struct page *page, int v) { atomic_set(&page->_count, v); + if (page_ref_tracepoint_active(__tracepoint_page_ref_set)) + __page_ref_set(page, v); } /* @@ -32,46 +90,74 @@ static inline void init_page_count(struct page *page) static inline void page_ref_add(struct page *page, int nr) { atomic_add(nr, &page->_count); + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) + __page_ref_mod(page, nr); } static inline void page_ref_sub(struct page *page, int nr) { atomic_sub(nr, &page->_count); + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) + __page_ref_mod(page, -nr); } static inline void page_ref_inc(struct page *page) { atomic_inc(&page->_count); + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) + __page_ref_mod(page, 1); } static inline void page_ref_dec(struct page *page) { atomic_dec(&page->_count); + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) + __page_ref_mod(page, -1); } static inline int page_ref_sub_and_test(struct page *page, int nr) { - return atomic_sub_and_test(nr, &page->_count); + int ret = atomic_sub_and_test(nr, &page->_count); + + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod_and_test)) + __page_ref_mod_and_test(page, -nr, ret); + return ret; } static inline int page_ref_dec_and_test(struct page *page) { - return atomic_dec_and_test(&page->_count); + int ret = atomic_dec_and_test(&page->_count); + + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod_and_test)) + __page_ref_mod_and_test(page, -1, ret); + return ret; } static inline int page_ref_dec_return(struct page *page) { - return atomic_dec_return(&page->_count); + int ret = atomic_dec_return(&page->_count); + + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod_and_return)) + __page_ref_mod_and_return(page, -1, ret); + return ret; } static inline int page_ref_add_unless(struct page *page, int nr, int u) { - return atomic_add_unless(&page->_count, nr, u); + int ret = atomic_add_unless(&page->_count, nr, u); + + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod_unless)) + __page_ref_mod_unless(page, nr, ret); + return ret; } static inline int page_ref_freeze(struct page *page, int count) { - return likely(atomic_cmpxchg(&page->_count, count, 0) == count); + int ret = likely(atomic_cmpxchg(&page->_count, count, 0) == count); + + if (page_ref_tracepoint_active(__tracepoint_page_ref_freeze)) + __page_ref_freeze(page, count, ret); + return ret; } static inline void page_ref_unfreeze(struct page *page, int count) @@ -80,6 +166,8 @@ static inline void page_ref_unfreeze(struct page *page, int count) VM_BUG_ON(count == 0); atomic_set(&page->_count, count); + if (page_ref_tracepoint_active(__tracepoint_page_ref_unfreeze)) + __page_ref_unfreeze(page, count); } #endif diff --git a/include/trace/events/page_ref.h b/include/trace/events/page_ref.h new file mode 100644 index 000000000000..81001f8b0db4 --- /dev/null +++ b/include/trace/events/page_ref.h @@ -0,0 +1,134 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM page_ref + +#if !defined(_TRACE_PAGE_REF_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PAGE_REF_H + +#include <linux/types.h> +#include <linux/page_ref.h> +#include <linux/tracepoint.h> +#include <trace/events/mmflags.h> + +DECLARE_EVENT_CLASS(page_ref_mod_template, + + TP_PROTO(struct page *page, int v), + + TP_ARGS(page, v), + + TP_STRUCT__entry( + __field(unsigned long, pfn) + __field(unsigned long, flags) + __field(int, count) + __field(int, mapcount) + __field(void *, mapping) + __field(int, mt) + __field(int, val) + ), + + TP_fast_assign( + __entry->pfn = page_to_pfn(page); + __entry->flags = page->flags; + __entry->count = page_ref_count(page); + __entry->mapcount = page_mapcount(page); + __entry->mapping = page->mapping; + __entry->mt = get_pageblock_migratetype(page); + __entry->val = v; + ), + + TP_printk("pfn=0x%lx flags=%s count=%d mapcount=%d mapping=%p mt=%d val=%d", + __entry->pfn, + show_page_flags(__entry->flags & ((1UL << NR_PAGEFLAGS) - 1)), + __entry->count, + __entry->mapcount, __entry->mapping, __entry->mt, + __entry->val) +); + +DEFINE_EVENT(page_ref_mod_template, page_ref_set, + + TP_PROTO(struct page *page, int v), + + TP_ARGS(page, v) +); + +DEFINE_EVENT(page_ref_mod_template, page_ref_mod, + + TP_PROTO(struct page *page, int v), + + TP_ARGS(page, v) +); + +DECLARE_EVENT_CLASS(page_ref_mod_and_test_template, + + TP_PROTO(struct page *page, int v, int ret), + + TP_ARGS(page, v, ret), + + TP_STRUCT__entry( + __field(unsigned long, pfn) + __field(unsigned long, flags) + __field(int, count) + __field(int, mapcount) + __field(void *, mapping) + __field(int, mt) + __field(int, val) + __field(int, ret) + ), + + TP_fast_assign( + __entry->pfn = page_to_pfn(page); + __entry->flags = page->flags; + __entry->count = page_ref_count(page); + __entry->mapcount = page_mapcount(page); + __entry->mapping = page->mapping; + __entry->mt = get_pageblock_migratetype(page); + __entry->val = v; + __entry->ret = ret; + ), + + TP_printk("pfn=0x%lx flags=%s count=%d mapcount=%d mapping=%p mt=%d val=%d ret=%d", + __entry->pfn, + show_page_flags(__entry->flags & ((1UL << NR_PAGEFLAGS) - 1)), + __entry->count, + __entry->mapcount, __entry->mapping, __entry->mt, + __entry->val, __entry->ret) +); + +DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_mod_and_test, + + TP_PROTO(struct page *page, int v, int ret), + + TP_ARGS(page, v, ret) +); + +DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_mod_and_return, + + TP_PROTO(struct page *page, int v, int ret), + + TP_ARGS(page, v, ret) +); + +DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_mod_unless, + + TP_PROTO(struct page *page, int v, int ret), + + TP_ARGS(page, v, ret) +); + +DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_freeze, + + TP_PROTO(struct page *page, int v, int ret), + + TP_ARGS(page, v, ret) +); + +DEFINE_EVENT(page_ref_mod_template, page_ref_unfreeze, + + TP_PROTO(struct page *page, int v), + + TP_ARGS(page, v) +); + +#endif /* _TRACE_PAGE_COUNT_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 5c50b238b770..22f4cd96acb0 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -79,3 +79,16 @@ config PAGE_POISONING_ZERO Enabling page poisoning with this option will disable hibernation If unsure, say N + bool + +config DEBUG_PAGE_REF + bool "Enable tracepoint to track down page reference manipulation" + depends on DEBUG_KERNEL + depends on TRACEPOINTS + ---help--- + This is a feature to add tracepoint for tracking down page reference + manipulation. This tracking is useful to diagnose functional failure + due to migration failures caused by page reference mismatches. Be + careful when enabling this feature because it adds about 30 KB to the + kernel code. However the runtime performance overhead is virtually + nil until the tracepoints are actually enabled. diff --git a/mm/Makefile b/mm/Makefile index cfdd481d27a5..6da300a1414b 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -81,3 +81,4 @@ obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o obj-$(CONFIG_USERFAULTFD) += userfaultfd.o obj-$(CONFIG_IDLE_PAGE_TRACKING) += page_idle.o obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o +obj-$(CONFIG_DEBUG_PAGE_REF) += debug_page_ref.o diff --git a/mm/debug_page_ref.c b/mm/debug_page_ref.c new file mode 100644 index 000000000000..1aef3d562e52 --- /dev/null +++ b/mm/debug_page_ref.c @@ -0,0 +1,54 @@ +#include <linux/mm_types.h> +#include <linux/tracepoint.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/page_ref.h> + +void __page_ref_set(struct page *page, int v) +{ + trace_page_ref_set(page, v); +} +EXPORT_SYMBOL(__page_ref_set); +EXPORT_TRACEPOINT_SYMBOL(page_ref_set); + +void __page_ref_mod(struct page *page, int v) +{ + trace_page_ref_mod(page, v); +} +EXPORT_SYMBOL(__page_ref_mod); +EXPORT_TRACEPOINT_SYMBOL(page_ref_mod); + +void __page_ref_mod_and_test(struct page *page, int v, int ret) +{ + trace_page_ref_mod_and_test(page, v, ret); +} +EXPORT_SYMBOL(__page_ref_mod_and_test); +EXPORT_TRACEPOINT_SYMBOL(page_ref_mod_and_test); + +void __page_ref_mod_and_return(struct page *page, int v, int ret) +{ + trace_page_ref_mod_and_return(page, v, ret); +} +EXPORT_SYMBOL(__page_ref_mod_and_return); +EXPORT_TRACEPOINT_SYMBOL(page_ref_mod_and_return); + +void __page_ref_mod_unless(struct page *page, int v, int u) +{ + trace_page_ref_mod_unless(page, v, u); +} +EXPORT_SYMBOL(__page_ref_mod_unless); +EXPORT_TRACEPOINT_SYMBOL(page_ref_mod_unless); + +void __page_ref_freeze(struct page *page, int v, int ret) +{ + trace_page_ref_freeze(page, v, ret); +} +EXPORT_SYMBOL(__page_ref_freeze); +EXPORT_TRACEPOINT_SYMBOL(page_ref_freeze); + +void __page_ref_unfreeze(struct page *page, int v) +{ + trace_page_ref_unfreeze(page, v); +} +EXPORT_SYMBOL(__page_ref_unfreeze); +EXPORT_TRACEPOINT_SYMBOL(page_ref_unfreeze); |