[PATCH] mm:slab: Adjust the print format for the slabinfo

[PATCH] mm:slab: Adjust the print format for the slabinfo

[jun qian]

Header and the corresponding information is not aligned,
adjust the printing format helps us to understand the slabinfo better.

Signed-off-by: jun qian <hangdianqj@163.com>
Cc: Barry song <21cnbao@gmail.com>
---
 mm/slab_common.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/mm/slab_common.c b/mm/slab_common.c
index fea3376f9816..07a324cbbfb6 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1263,9 +1263,13 @@ static void print_slabinfo_header(struct seq_file *m)
 #else
 	seq_puts(m, "slabinfo - version: 2.1\n");
 #endif
-	seq_puts(m, "# name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
-	seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
-	seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
+	seq_printf(m, "%-22s %-14s %-11s %-10s %-13s %-14s",
+		  "# name", "<active_objs>", "<num_objs>", "<objsize>",
+		  "<objperslab>", "<pagesperslab>");
+	seq_printf(m, " : %-9s %-8s %-13s %-14s",
+		  "tunables", "<limit>", "<batchcount>", "<sharedfactor>");
+	seq_printf(m, " : %-9s %-15s %-12s %-16s",
+		  "slabdata", "<active_slabs>", "<num_slabs>", "<sharedavail>");
 #ifdef CONFIG_DEBUG_SLAB
 	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
 	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
@@ -1319,13 +1323,13 @@ static void cache_show(struct kmem_cache *s, struct seq_file *m)
 
 	memcg_accumulate_slabinfo(s, &sinfo);
 
-	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
+	seq_printf(m, "%-22s %-14lu %-11lu %-10u %-13u %-14d",
 		   cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
 		   sinfo.objects_per_slab, (1 << sinfo.cache_order));
 
-	seq_printf(m, " : tunables %4u %4u %4u",
+	seq_printf(m, " : %-9s %-8u %-13u %-14u", "tunables",
 		   sinfo.limit, sinfo.batchcount, sinfo.shared);
-	seq_printf(m, " : slabdata %6lu %6lu %6lu",
+	seq_printf(m, " : %-9s %-15lu %-12lu %-16lu", "slabdata",
 		   sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
 	slabinfo_show_stats(m, s);
 	seq_putc(m, '\n');
-- 
2.17.1

Re: [PATCH] mm:slab: Adjust the print format for the slabinfo

[Michal Hocko]

On Mon 01-10-18 19:59:39, jun qian wrote:
> Header and the corresponding information is not aligned,
> adjust the printing format helps us to understand the slabinfo better.

What prevents you from formating the output when printint the file? In
other words why do we want to do special formating in the kernel?
 
> Signed-off-by: jun qian <hangdianqj@163.com>
> Cc: Barry song <21cnbao@gmail.com>
> ---
>  mm/slab_common.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index fea3376f9816..07a324cbbfb6 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -1263,9 +1263,13 @@ static void print_slabinfo_header(struct seq_file *m)
>  #else
>  	seq_puts(m, "slabinfo - version: 2.1\n");
>  #endif
> -	seq_puts(m, "# name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
> -	seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
> -	seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
> +	seq_printf(m, "%-22s %-14s %-11s %-10s %-13s %-14s",
> +		  "# name", "<active_objs>", "<num_objs>", "<objsize>",
> +		  "<objperslab>", "<pagesperslab>");
> +	seq_printf(m, " : %-9s %-8s %-13s %-14s",
> +		  "tunables", "<limit>", "<batchcount>", "<sharedfactor>");
> +	seq_printf(m, " : %-9s %-15s %-12s %-16s",
> +		  "slabdata", "<active_slabs>", "<num_slabs>", "<sharedavail>");
>  #ifdef CONFIG_DEBUG_SLAB
>  	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
>  	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
> @@ -1319,13 +1323,13 @@ static void cache_show(struct kmem_cache *s, struct seq_file *m)
>  
>  	memcg_accumulate_slabinfo(s, &sinfo);
>  
> -	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
> +	seq_printf(m, "%-22s %-14lu %-11lu %-10u %-13u %-14d",
>  		   cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
>  		   sinfo.objects_per_slab, (1 << sinfo.cache_order));
>  
> -	seq_printf(m, " : tunables %4u %4u %4u",
> +	seq_printf(m, " : %-9s %-8u %-13u %-14u", "tunables",
>  		   sinfo.limit, sinfo.batchcount, sinfo.shared);
> -	seq_printf(m, " : slabdata %6lu %6lu %6lu",
> +	seq_printf(m, " : %-9s %-15lu %-12lu %-16lu", "slabdata",
>  		   sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
>  	slabinfo_show_stats(m, s);
>  	seq_putc(m, '\n');
> -- 
> 2.17.1
> 
> 

-- 
Michal Hocko
SUSE Labs

Re: [PATCH] mm:slab: Adjust the print format for the slabinfo

[Vlastimil Babka]

On 10/2/18 4:59 AM, jun qian wrote:
> Header and the corresponding information is not aligned,
> adjust the printing format helps us to understand the slabinfo better.
> 
> Signed-off-by: jun qian <hangdianqj@163.com>
> Cc: Barry song <21cnbao@gmail.com>

I've tried the patch and it makes the slabinfo not fit my screen
anymore, and the value density is very sparse. IMHO the current layout
is better, sorry.

Vlastimil