tracing, mm: Record pfn instead of pointer to struct page

The struct page is opaque for userspace tools, so it'd be better to save
pfn in order to identify page frames.

The textual output of $debugfs/tracing/trace file remains unchanged and
only raw (binary) data format is changed - but thanks to libtraceevent,
userspace tools which deal with the raw data (like perf and trace-cmd)
can parse the format easily.  So impact on the userspace will also be
minimal.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Based-on-patch-by: Joonsoo Kim <js1304@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1428298576-9785-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/include/trace/events/filemap.h b/include/trace/events/filemap.h
index 0421f49a20f7a2af50ca0ab7e7280455d1871367..42febb6bc1d56a00256a62cbb9149c3b5e3c92a7 100644 (file)
--- a/include/trace/events/filemap.h
+++ b/include/trace/events/filemap.h
@@ -18,14 +18,14 @@ DECLARE_EVENT_CLASS(mm_filemap_op_page_cache,
        TP_ARGS(page),
 
        TP_STRUCT__entry(
-               __field(struct page *, page)
+               __field(unsigned long, pfn)
                __field(unsigned long, i_ino)
                __field(unsigned long, index)
                __field(dev_t, s_dev)
        ),
 
        TP_fast_assign(
-               __entry->page = page;
+               __entry->pfn = page_to_pfn(page);
                __entry->i_ino = page->mapping->host->i_ino;
                __entry->index = page->index;
                if (page->mapping->host->i_sb)
@@ -37,8 +37,8 @@ DECLARE_EVENT_CLASS(mm_filemap_op_page_cache,
        TP_printk("dev %d:%d ino %lx page=%p pfn=%lu ofs=%lu",
                MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
                __entry->i_ino,
-               __entry->page,
-               page_to_pfn(__entry->page),
+               pfn_to_page(__entry->pfn),
+               __entry->pfn,
                __entry->index << PAGE_SHIFT)
 );
 

diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index 4ad10baecd4dcddbb47e503ccc41b1c309aaba3c..81ea598121173bf782c04f7c6bfae63b5207b75e 100644 (file)
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -154,18 +154,18 @@ TRACE_EVENT(mm_page_free,
        TP_ARGS(page, order),
 
        TP_STRUCT__entry(
-               __field(        struct page *,  page            )
+               __field(        unsigned long,  pfn             )
                __field(        unsigned int,   order           )
        ),
 
        TP_fast_assign(
-               __entry->page           = page;
+               __entry->pfn            = page_to_pfn(page);
                __entry->order          = order;
        ),
 
        TP_printk("page=%p pfn=%lu order=%d",
-                       __entry->page,
-                       page_to_pfn(__entry->page),
+                       pfn_to_page(__entry->pfn),
+                       __entry->pfn,
                        __entry->order)
 );
 
@@ -176,18 +176,18 @@ TRACE_EVENT(mm_page_free_batched,
        TP_ARGS(page, cold),
 
        TP_STRUCT__entry(
-               __field(        struct page *,  page            )
+               __field(        unsigned long,  pfn             )
                __field(        int,            cold            )
        ),
 
        TP_fast_assign(
-               __entry->page           = page;
+               __entry->pfn            = page_to_pfn(page);
                __entry->cold           = cold;
        ),
 
        TP_printk("page=%p pfn=%lu order=0 cold=%d",
-                       __entry->page,
-                       page_to_pfn(__entry->page),
+                       pfn_to_page(__entry->pfn),
+                       __entry->pfn,
                        __entry->cold)
 );
 
@@ -199,22 +199,22 @@ TRACE_EVENT(mm_page_alloc,
        TP_ARGS(page, order, gfp_flags, migratetype),
 
        TP_STRUCT__entry(
-               __field(        struct page *,  page            )
+               __field(        unsigned long,  pfn             )
                __field(        unsigned int,   order           )
                __field(        gfp_t,          gfp_flags       )
                __field(        int,            migratetype     )
        ),
 
        TP_fast_assign(
-               __entry->page           = page;
+               __entry->pfn            = page ? page_to_pfn(page) : -1UL;
                __entry->order          = order;
                __entry->gfp_flags      = gfp_flags;
                __entry->migratetype    = migratetype;
        ),
 
        TP_printk("page=%p pfn=%lu order=%d migratetype=%d gfp_flags=%s",
-               __entry->page,
-               __entry->page ? page_to_pfn(__entry->page) : 0,
+               __entry->pfn != -1UL ? pfn_to_page(__entry->pfn) : NULL,
+               __entry->pfn != -1UL ? __entry->pfn : 0,
                __entry->order,
                __entry->migratetype,
                show_gfp_flags(__entry->gfp_flags))
@@ -227,20 +227,20 @@ DECLARE_EVENT_CLASS(mm_page,
        TP_ARGS(page, order, migratetype),
 
        TP_STRUCT__entry(
-               __field(        struct page *,  page            )
+               __field(        unsigned long,  pfn             )
                __field(        unsigned int,   order           )
                __field(        int,            migratetype     )
        ),
 
        TP_fast_assign(
-               __entry->page           = page;
+               __entry->pfn            = page ? page_to_pfn(page) : -1UL;
                __entry->order          = order;
                __entry->migratetype    = migratetype;
        ),
 
        TP_printk("page=%p pfn=%lu order=%u migratetype=%d percpu_refill=%d",
-               __entry->page,
-               __entry->page ? page_to_pfn(__entry->page) : 0,
+               __entry->pfn != -1UL ? pfn_to_page(__entry->pfn) : NULL,
+               __entry->pfn != -1UL ? __entry->pfn : 0,
                __entry->order,
                __entry->migratetype,
                __entry->order == 0)
@@ -260,7 +260,7 @@ DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain,
        TP_ARGS(page, order, migratetype),
 
        TP_printk("page=%p pfn=%lu order=%d migratetype=%d",
-               __entry->page, page_to_pfn(__entry->page),
+               pfn_to_page(__entry->pfn), __entry->pfn,
                __entry->order, __entry->migratetype)
 );
 
@@ -275,7 +275,7 @@ TRACE_EVENT(mm_page_alloc_extfrag,
                alloc_migratetype, fallback_migratetype),
 
        TP_STRUCT__entry(
-               __field(        struct page *,  page                    )
+               __field(        unsigned long,  pfn                     )
                __field(        int,            alloc_order             )
                __field(        int,            fallback_order          )
                __field(        int,            alloc_migratetype       )
@@ -284,7 +284,7 @@ TRACE_EVENT(mm_page_alloc_extfrag,
        ),
 
        TP_fast_assign(
-               __entry->page                   = page;
+               __entry->pfn                    = page_to_pfn(page);
                __entry->alloc_order            = alloc_order;
                __entry->fallback_order         = fallback_order;
                __entry->alloc_migratetype      = alloc_migratetype;
@@ -294,8 +294,8 @@ TRACE_EVENT(mm_page_alloc_extfrag,
        ),
 
        TP_printk("page=%p pfn=%lu alloc_order=%d fallback_order=%d pageblock_order=%d alloc_migratetype=%d fallback_migratetype=%d fragmenting=%d change_ownership=%d",
-               __entry->page,
-               page_to_pfn(__entry->page),
+               pfn_to_page(__entry->pfn),
+               __entry->pfn,
                __entry->alloc_order,
                __entry->fallback_order,
                pageblock_order,

diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 69590b6ffc091116911b29dffbb64871bd9f92b1..f66476b96264cec3cc11f7797bd8fb3acac64de7 100644 (file)
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -336,18 +336,18 @@ TRACE_EVENT(mm_vmscan_writepage,
        TP_ARGS(page, reclaim_flags),
 
        TP_STRUCT__entry(
-               __field(struct page *, page)
+               __field(unsigned long, pfn)
                __field(int, reclaim_flags)
        ),
 
        TP_fast_assign(
-               __entry->page = page;
+               __entry->pfn = page_to_pfn(page);
                __entry->reclaim_flags = reclaim_flags;
        ),
 
        TP_printk("page=%p pfn=%lu flags=%s",
-               __entry->page,
-               page_to_pfn(__entry->page),
+               pfn_to_page(__entry->pfn),
+               __entry->pfn,
                show_reclaim_flags(__entry->reclaim_flags))
 );