[PATCHv3 4/4] zsmalloc: show per fullness group class stats

[Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>]

We keep the old fullness (3/4 threshold) reporting in
zs_stats_size_show(). Switch from allmost full/empty
stats to fine-grained per inuse ratio (fullness group)
reporting, which gives signicantly more data on classes
fragmentation.

Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
 mm/zsmalloc.c | 50 +++++++++++++++++++++++---------------------------
 1 file changed, 23 insertions(+), 27 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 141a3f69b642..5ee9a76b3446 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -172,9 +172,7 @@
 enum fullness_group {
 	ZS_INUSE_RATIO_0,
 	ZS_INUSE_RATIO_10,
-	/* NOTE: 5 more fullness groups here */
-	ZS_INUSE_RATIO_70	= 7,
-	/* NOTE: 2 more fullness groups here */
+	/* NOTE: 8 more fullness groups here */
 	ZS_INUSE_RATIO_99       = 10,
 	ZS_INUSE_RATIO_100,
 	NR_FULLNESS_GROUPS,
@@ -625,19 +623,19 @@ static int zs_stats_size_show(struct seq_file *s, void *v)
 	struct zs_pool *pool = s->private;
 	struct size_class *class;
 	int objs_per_zspage;
-	unsigned long class_almost_full, class_almost_empty;
 	unsigned long obj_allocated, obj_used, pages_used, freeable;
-	unsigned long total_class_almost_full = 0, total_class_almost_empty = 0;
 	unsigned long total_objs = 0, total_used_objs = 0, total_pages = 0;
 	unsigned long total_freeable = 0;
+	unsigned long inuse_totals[NR_FULLNESS_GROUPS] = {0, };
+	int fg;
 
-	seq_printf(s, " %5s %5s %11s %12s %13s %10s %10s %16s %8s\n",
-			"class", "size", "almost_full", "almost_empty",
+	seq_printf(s, " %5s %5s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s %8s %13s %10s %10s %16s %8s\n",
+			"class", "size", "10%", "20%", "30%", "40%",
+			"50%", "60%", "70%", "80%", "90%", "99%", "100%",
 			"obj_allocated", "obj_used", "pages_used",
 			"pages_per_zspage", "freeable");
 
 	for (i = 0; i < ZS_SIZE_CLASSES; i++) {
-		int fg;
 
 		class = pool->size_class[i];
 
@@ -646,14 +644,12 @@ static int zs_stats_size_show(struct seq_file *s, void *v)
 
 		spin_lock(&pool->lock);
 
-		/*
-		 * Replecate old behaviour for almost_full and almost_empty
-		 * stats.
-		 */
-		for (fg = ZS_INUSE_RATIO_70; fg <= ZS_INUSE_RATIO_99; fg++)
-			class_almost_full = zs_stat_get(class, fg);
-		for (fg = ZS_INUSE_RATIO_10; fg < ZS_INUSE_RATIO_70; fg++)
-			class_almost_empty = zs_stat_get(class, fg);
+		seq_printf(s, " %5u %5u ", i, class->size);
+
+		for (fg = ZS_INUSE_RATIO_10; fg <= ZS_INUSE_RATIO_100; fg++) {
+			inuse_totals[fg] += zs_stat_get(class, fg);
+			seq_printf(s, "%8lu ", zs_stat_get(class, fg));
+		}
 
 		obj_allocated = zs_stat_get(class, ZS_OBJS_ALLOCATED);
 		obj_used = zs_stat_get(class, ZS_OBJS_INUSE);
@@ -664,14 +660,10 @@ static int zs_stats_size_show(struct seq_file *s, void *v)
 		pages_used = obj_allocated / objs_per_zspage *
 				class->pages_per_zspage;
 
-		seq_printf(s, " %5u %5u %11lu %12lu %13lu"
-				" %10lu %10lu %16d %8lu\n",
-			i, class->size, class_almost_full, class_almost_empty,
-			obj_allocated, obj_used, pages_used,
-			class->pages_per_zspage, freeable);
+		seq_printf(s, "%13lu %10lu %10lu %16d %8lu\n",
+			   obj_allocated, obj_used, pages_used,
+			   class->pages_per_zspage, freeable);
 
-		total_class_almost_full += class_almost_full;
-		total_class_almost_empty += class_almost_empty;
 		total_objs += obj_allocated;
 		total_used_objs += obj_used;
 		total_pages += pages_used;
@@ -679,10 +671,14 @@ static int zs_stats_size_show(struct seq_file *s, void *v)
 	}
 
 	seq_puts(s, "\n");
-	seq_printf(s, " %5s %5s %11lu %12lu %13lu %10lu %10lu %16s %8lu\n",
-			"Total", "", total_class_almost_full,
-			total_class_almost_empty, total_objs,
-			total_used_objs, total_pages, "", total_freeable);
+	seq_printf(s, " %5s %5s ", "Total", "");
+
+	for (fg = ZS_INUSE_RATIO_10; fg <= ZS_INUSE_RATIO_100; fg++)
+		seq_printf(s, "%8lu ", inuse_totals[fg]);
+
+	seq_printf(s, "%13lu %10lu %10lu %16s %8lu\n",
+		   total_objs, total_used_objs, total_pages, "",
+		   total_freeable);
 
 	return 0;
 }
-- 
2.40.0.rc0.216.gc4246ad0f0-goog