On Mon, 8 Mar 2021 20:50:00 +0200 Ovidiu Panait <[email protected]> wrote:
> Adjust the rss_stat tracepoint to print the name of the resident page type > that got updated(e.g. MM_ANONPAGES/MM_FILEPAGES), rather than the numeric > index corresponding to it(the __entry->member value): > > Before this patch: > ------------------ > rss_stat: mm_id=1216113068 curr=0 member=1 size=28672B > rss_stat: mm_id=1216113068 curr=0 member=1 size=0B > rss_stat: mm_id=534402304 curr=1 member=0 size=188416B > rss_stat: mm_id=534402304 curr=1 member=1 size=40960B > > After this patch: > ----------------- > rss_stat: mm_id=1726253524 curr=1 type=MM_ANONPAGES size=40960B > rss_stat: mm_id=1726253524 curr=1 type=MM_FILEPAGES size=663552B > rss_stat: mm_id=1726253524 curr=1 type=MM_ANONPAGES size=65536B > rss_stat: mm_id=1726253524 curr=1 type=MM_FILEPAGES size=647168B > > Also, make the resident_page_types[] array in kernel/fork.c non-static so > that it can be reused from tracing code. > > Signed-off-by: Ovidiu Panait <[email protected]> > --- > include/linux/mm.h | 2 ++ > include/trace/events/kmem.h | 5 +++-- > kernel/fork.c | 2 +- > 3 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 89fca443e6f1..7916112d5952 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3141,5 +3141,7 @@ void mem_dump_obj(void *object); > static inline void mem_dump_obj(void *object) {} > #endif > > +extern const char * const resident_page_types[]; > + > #endif /* __KERNEL__ */ > #endif /* _LINUX_MM_H */ > diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h > index 3a60b6b6db32..623506917cd0 100644 > --- a/include/trace/events/kmem.h > +++ b/include/trace/events/kmem.h > @@ -5,6 +5,7 @@ > #if !defined(_TRACE_KMEM_H) || defined(TRACE_HEADER_MULTI_READ) > #define _TRACE_KMEM_H > > +#include <linux/mm.h> > #include <linux/types.h> > #include <linux/tracepoint.h> > #include <trace/events/mmflags.h> > @@ -365,10 +366,10 @@ TRACE_EVENT(rss_stat, > __entry->size = (count << PAGE_SHIFT); > ), > > - TP_printk("mm_id=%u curr=%d member=%d size=%ldB", > + TP_printk("mm_id=%u curr=%d type=%s size=%ldB", > __entry->mm_id, > __entry->curr, > - __entry->member, > + resident_page_types[__entry->member], This will be useless for user space tools that parse the raw data. The correct way is to have before this: #define TRACE_MM_PAGES \ EM(MM_FILEPAGES) \ EM(MM_ANONPAGES) \ EM(MM_SWAPENTS) \ EMe(MM_SHMEMPAGES) #undef EM #undef EMe #define EM(a) TRACE_DEFINE_ENUM(a); #define EMe(a) TRACE_DEFINE_ENUM(a); TRACE_MM_PAGES #undef EM #undef EMe #define EM(a) { a, #a }, #define EMe(a) { a, #a } Then you can have: TP_printk("mm_id=%u curr=%d type=%s size=%1dB", __entry->mm_id, __entry->curr, __print_symbolic(__entry->member, TRACE_MM_PAGES), > __entry->size) > ); > #endif /* _TRACE_KMEM_H */ And then this will work fine for user space as well. Other events have done this, for example, see include/trace/events/writeback.h -- Steve > diff --git a/kernel/fork.c b/kernel/fork.c > index d3171e8e88e5..b30fe8ca56b3 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -128,7 +128,7 @@ static int max_threads; /* tunable limit on > nr_threads */ > > #define NAMED_ARRAY_INDEX(x) [x] = __stringify(x) > > -static const char * const resident_page_types[] = { > +const char * const resident_page_types[] = { > NAMED_ARRAY_INDEX(MM_FILEPAGES), > NAMED_ARRAY_INDEX(MM_ANONPAGES), > NAMED_ARRAY_INDEX(MM_SWAPENTS),
