Re: [PATCH V2 6/7] proc: show MADV_FREE pages info in smaps

[Shaohua Li <shli@fb.com>]

On Fri, Feb 10, 2017 at 02:30:40PM +0100, Michal Hocko wrote:
> $DESCRIPTION_OF_YOUR_USECASE_GOES_HERE
> 
> Moreover Documentation/filesystems/proc.txt should be updated as well.
> 
> Other than that, the patch looks good to me.

Ok, will add more description and add doc for proc.txt. I don't have solid use
case for this though. It's consistent with other info we exported to userspace
and mostly for diagnosing purpose.

Thanks,
Shaohua
 
> On Fri 03-02-17 15:33:22, Shaohua Li wrote:
> > Cc: Michal Hocko <mhocko@suse.com>
> > Cc: Minchan Kim <minchan@kernel.org>
> > Cc: Hugh Dickins <hughd@google.com>
> > Cc: Johannes Weiner <hannes@cmpxchg.org>
> > Cc: Rik van Riel <riel@redhat.com>
> > Cc: Mel Gorman <mgorman@techsingularity.net>
> > Cc: Andrew Morton <akpm@linux-foundation.org>
> > Signed-off-by: Shaohua Li <shli@fb.com>
> 
> after the description is added and documentation updated
> Acked-by: Michal Hocko <mhocko@suse.com>
> 
> > ---
> >  fs/proc/task_mmu.c | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> > index ee3efb2..8f2423f 100644
> > --- a/fs/proc/task_mmu.c
> > +++ b/fs/proc/task_mmu.c
> > @@ -440,6 +440,7 @@ struct mem_size_stats {
> >  	unsigned long private_dirty;
> >  	unsigned long referenced;
> >  	unsigned long anonymous;
> > +	unsigned long lazyfree;
> >  	unsigned long anonymous_thp;
> >  	unsigned long shmem_thp;
> >  	unsigned long swap;
> > @@ -456,8 +457,11 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
> >  	int i, nr = compound ? 1 << compound_order(page) : 1;
> >  	unsigned long size = nr * PAGE_SIZE;
> >  
> > -	if (PageAnon(page))
> > +	if (PageAnon(page)) {
> >  		mss->anonymous += size;
> > +		if (!PageSwapBacked(page))
> > +			mss->lazyfree += size;
> > +	}
> >  
> >  	mss->resident += size;
> >  	/* Accumulate the size in pages that have been accessed. */
> > @@ -770,6 +774,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
> >  		   "Private_Dirty:  %8lu kB\n"
> >  		   "Referenced:     %8lu kB\n"
> >  		   "Anonymous:      %8lu kB\n"
> > +		   "LazyFree:       %8lu kB\n"
> >  		   "AnonHugePages:  %8lu kB\n"
> >  		   "ShmemPmdMapped: %8lu kB\n"
> >  		   "Shared_Hugetlb: %8lu kB\n"
> > @@ -788,6 +793,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
> >  		   mss.private_dirty >> 10,
> >  		   mss.referenced >> 10,
> >  		   mss.anonymous >> 10,
> > +		   mss.lazyfree >> 10,
> >  		   mss.anonymous_thp >> 10,
> >  		   mss.shmem_thp >> 10,
> >  		   mss.shared_hugetlb >> 10,
> > -- 
> > 2.9.3
> > 
> 
> -- 
> Michal Hocko
> SUSE Labs