On Sun, Nov 06, 2022 at 01:23:15PM -0500, Steven Rostedt wrote:
> 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.
Oh, I wasn't aware of it. I think I can use the field 'mapcount' to
represent both mapcount and page_type as they have same offset and size
within the structure.
Just wondering where this constraint came from...
>
> > __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)
>
--
Thanks,
Hyeonggon
