On Sun, 6 Nov 2022 23:03:54 +0900
Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> wrote:
> Some page flags are not actually set in 'flags' field. To provide
> better understanding of tracepoint output, introduce show_page_types()
> that shows page flags from page_type.
>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
> Cc: Marco Elver <elver@xxxxxxxxxx>
> Cc: Vasily Averin <vasily.averin@xxxxxxxxx>
> Cc: NeilBrown <neilb@xxxxxxx>
> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
> ---
> include/trace/events/mmflags.h | 12 ++++++++++++
> include/trace/events/page_ref.h | 10 ++++++++--
> 2 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
> index 72c11a16f771..a8dfb98a4dd6 100644
> --- a/include/trace/events/mmflags.h
> +++ b/include/trace/events/mmflags.h
> @@ -136,6 +136,18 @@ IF_HAVE_PG_SKIP_KASAN_POISON(PG_skip_kasan_poison, "skip_kasan_poison")
> __def_pageflag_names \
> ) : "none"
>
> +#define __def_pagetype_names \
> + {PG_slab, "slab" }, \
> + {PG_offline, "offline" }, \
> + {PG_guard, "guard" }, \
> + {PG_table, "table" }, \
> + {PG_buddy, "buddy" }
> +
> +#define show_page_types(page_type) \
> + page_type_has_type(page_type) ? \
> + __print_flags((~page_type), "|", __def_pagetype_names) \
> + : "none"
> +
> #if defined(CONFIG_X86)
> #define __VM_ARCH_SPECIFIC_1 {VM_PAT, "pat" }
> #elif defined(CONFIG_PPC)
> diff --git a/include/trace/events/page_ref.h b/include/trace/events/page_ref.h
> index 8a99c1cd417b..b00d23e90e93 100644
> --- a/include/trace/events/page_ref.h
> +++ b/include/trace/events/page_ref.h
> @@ -21,6 +21,7 @@ DECLARE_EVENT_CLASS(page_ref_mod_template,
> __field(unsigned long, flags)
> __field(int, count)
> __field(int, mapcount)
> + __field(unsigned int, page_type)
Be careful were you add int fields for 64 bit machines.
The above is going to add 4 bytes of nothing in the ring buffer for
each event. Please try to keep ints together by 2s, especially between
long and pointer fields.
> __field(void *, mapping)
> __field(int, mt)
> __field(int, val)
> @@ -31,14 +32,16 @@ DECLARE_EVENT_CLASS(page_ref_mod_template,
> __entry->flags = page->flags;
> __entry->count = page_ref_count(page);
> __entry->mapcount = page_mapcount(page);
> + __entry->page_type = page->page_type;
> __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",
> + TP_printk("pfn=0x%lx flags=%s page_type=%s count=%d mapcount=%d mapping=%p mt=%d val=%d",
> __entry->pfn,
> show_page_flags(__entry->flags & PAGEFLAGS_MASK),
> + show_page_types(__entry->page_type & PAGE_TYPE_MASK),
> __entry->count,
> __entry->mapcount, __entry->mapping, __entry->mt,
> __entry->val)
> @@ -69,6 +72,7 @@ DECLARE_EVENT_CLASS(page_ref_mod_and_test_template,
> __field(unsigned long, flags)
> __field(int, count)
> __field(int, mapcount)
> + __field(unsigned int, page_type)
Here too.
-- Steve
> __field(void *, mapping)
> __field(int, mt)
> __field(int, val)
> @@ -80,15 +84,17 @@ DECLARE_EVENT_CLASS(page_ref_mod_and_test_template,
> __entry->flags = page->flags;
> __entry->count = page_ref_count(page);
> __entry->mapcount = page_mapcount(page);
> + __entry->page_type = page->page_type;
> __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",
> + TP_printk("pfn=0x%lx flags=%s page_type=%s count=%d mapcount=%d mapping=%p mt=%d val=%d ret=%d",
> __entry->pfn,
> show_page_flags(__entry->flags & PAGEFLAGS_MASK),
> + show_page_types(__entry->page_type & PAGE_TYPE_MASK),
> __entry->count,
> __entry->mapcount, __entry->mapping, __entry->mt,
> __entry->val, __entry->ret)
