[PATCH 03/10] lib: add a batch size to fprop_global

[Josef Bacik <josef@xxxxxxxxxxxxxx>]

From: Josef Bacik <jbacik@xxxxxx>

The flexible proportion stuff has been used to track how many pages we
are writing out over a period of time, so counts everything in single
increments.  If we wanted to use another base value we need to be able
to adjust the batch size to fit our the units we'll be using for the
proportions.

Signed-off-by: Josef Bacik <jbacik@xxxxxx>
---
 include/linux/flex_proportions.h |  4 +++-
 lib/flex_proportions.c           | 11 +++++------
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/include/linux/flex_proportions.h b/include/linux/flex_proportions.h
index 0d348e011a6e..853f4305d1b2 100644
--- a/include/linux/flex_proportions.h
+++ b/include/linux/flex_proportions.h
@@ -20,7 +20,7 @@
  */
 #define FPROP_FRAC_SHIFT 10
 #define FPROP_FRAC_BASE (1UL << FPROP_FRAC_SHIFT)
-
+#define FPROP_BATCH_SIZE (8*(1+ilog2(nr_cpu_ids)))
 /*
  * ---- Global proportion definitions ----
  */
@@ -31,6 +31,8 @@ struct fprop_global {
 	unsigned int period;
 	/* Synchronization with period transitions */
 	seqcount_t sequence;
+	/* batch size */
+	s32 batch_size;
 };
 
 int fprop_global_init(struct fprop_global *p, gfp_t gfp);
diff --git a/lib/flex_proportions.c b/lib/flex_proportions.c
index 2cc1f94e03a1..5552523b663a 100644
--- a/lib/flex_proportions.c
+++ b/lib/flex_proportions.c
@@ -44,6 +44,7 @@ int fprop_global_init(struct fprop_global *p, gfp_t gfp)
 	if (err)
 		return err;
 	seqcount_init(&p->sequence);
+	p->batch_size = FPROP_BATCH_SIZE;
 	return 0;
 }
 
@@ -166,8 +167,6 @@ void fprop_fraction_single(struct fprop_global *p,
 /*
  * ---- PERCPU ----
  */
-#define PROP_BATCH (8*(1+ilog2(nr_cpu_ids)))
-
 int fprop_local_init_percpu(struct fprop_local_percpu *pl, gfp_t gfp)
 {
 	int err;
@@ -204,11 +203,11 @@ static void fprop_reflect_period_percpu(struct fprop_global *p,
 	if (period - pl->period < BITS_PER_LONG) {
 		s64 val = percpu_counter_read(&pl->events);
 
-		if (val < (nr_cpu_ids * PROP_BATCH))
+		if (val < (nr_cpu_ids * p->batch_size))
 			val = percpu_counter_sum(&pl->events);
 
 		percpu_counter_add_batch(&pl->events,
-			-val + (val >> (period-pl->period)), PROP_BATCH);
+			-val + (val >> (period-pl->period)), p->batch_size);
 	} else
 		percpu_counter_set(&pl->events, 0);
 	pl->period = period;
@@ -219,7 +218,7 @@ static void fprop_reflect_period_percpu(struct fprop_global *p,
 void __fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl)
 {
 	fprop_reflect_period_percpu(p, pl);
-	percpu_counter_add_batch(&pl->events, 1, PROP_BATCH);
+	percpu_counter_add_batch(&pl->events, 1, p->batch_size);
 	percpu_counter_add(&p->events, 1);
 }
 
@@ -267,6 +266,6 @@ void __fprop_inc_percpu_max(struct fprop_global *p,
 			return;
 	} else
 		fprop_reflect_period_percpu(p, pl);
-	percpu_counter_add_batch(&pl->events, 1, PROP_BATCH);
+	percpu_counter_add_batch(&pl->events, 1, p->batch_size);
 	percpu_counter_add(&p->events, 1);
 }
-- 
2.7.5