Re: [PATCH 4/7] mm, vmscan: show LRU name in mm_vmscan_lru_isolate tracepoint

[Michal Hocko <mhocko@kernel.org>]

On Tue 03-01-17 18:08:58, Vlastimil Babka wrote:
> On 12/28/2016 04:30 PM, Michal Hocko wrote:
> > From: Michal Hocko <mhocko@suse.com>
> > 
> > mm_vmscan_lru_isolate currently prints only whether the LRU we isolate
> > from is file or anonymous but we do not know which LRU this is. It is
> > useful to know whether the list is file or anonymous as well. Change
> > the tracepoint to show symbolic names of the lru rather.
> > 
> > Signed-off-by: Michal Hocko <mhocko@suse.com>
> > ---
> >  include/trace/events/vmscan.h | 20 ++++++++++++++------
> >  mm/vmscan.c                   |  2 +-
> >  2 files changed, 15 insertions(+), 7 deletions(-)
> > 
> > diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
> > index 6af4dae46db2..cc0b4c456c78 100644
> > --- a/include/trace/events/vmscan.h
> > +++ b/include/trace/events/vmscan.h
> > @@ -36,6 +36,14 @@
> >  		(RECLAIM_WB_ASYNC) \
> >  	)
> > 
> > +#define show_lru_name(lru) \
> > +	__print_symbolic(lru, \
> > +			{LRU_INACTIVE_ANON, "LRU_INACTIVE_ANON"}, \
> > +			{LRU_ACTIVE_ANON, "LRU_ACTIVE_ANON"}, \
> > +			{LRU_INACTIVE_FILE, "LRU_INACTIVE_FILE"}, \
> > +			{LRU_ACTIVE_FILE, "LRU_ACTIVE_FILE"}, \
> > +			{LRU_UNEVICTABLE, "LRU_UNEVICTABLE"})
> > +
> 
> Does this work with external tools such as trace-cmd, i.e. does it export
> the correct format file?

How do I find out?

> I wouldn't expect it to be that easy to avoid the EM()/EMe() dance :)

Well, I will not pretend I understand the EM dances...

> Also can we make the symbolic names lower_case and without the LRU_ prefix?
> I think it's more consistent with other mm tracepoints, shorter and nicer.

OK, will make it lowercase without the LRU_ prefix.

-- 
Michal Hocko
SUSE Labs