[PATCH 3/5] blk-throttle: Define readable macros instead of static variables

From: Baolin Wang
Date: Mon Sep 07 2020 - 04:12:08 EST


The 'throtl_grp_quantum' and 'throtl_quantum' are both read-only
variables, thus better to use readable macros instead of static
variables, which can also save some spaces for .bss area.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
---
block/blk-throttle.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 06e73ed..ca9002d 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -15,10 +15,10 @@
#include "blk-cgroup-rwstat.h"

/* Max dispatch from a group in 1 round */
-static int throtl_grp_quantum = 8;
+#define THROTL_GRP_QUANTUM 8

/* Total max dispatch from all groups in one round */
-static int throtl_quantum = 32;
+#define THROTL_QUANTUM 32

/* Throttling is performed over a slice and after that slice is renewed */
#define DFL_THROTL_SLICE_HD (HZ / 10)
@@ -1175,8 +1175,8 @@ static int throtl_dispatch_tg(struct throtl_grp *tg)
{
struct throtl_service_queue *sq = &tg->service_queue;
unsigned int nr_reads = 0, nr_writes = 0;
- unsigned int max_nr_reads = throtl_grp_quantum*3/4;
- unsigned int max_nr_writes = throtl_grp_quantum - max_nr_reads;
+ unsigned int max_nr_reads = THROTL_GRP_QUANTUM * 3 / 4;
+ unsigned int max_nr_writes = THROTL_GRP_QUANTUM - max_nr_reads;
struct bio *bio;

/* Try to dispatch 75% READS and 25% WRITES */
@@ -1226,7 +1226,7 @@ static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
if (sq->nr_queued[0] || sq->nr_queued[1])
tg_update_disptime(tg);

- if (nr_disp >= throtl_quantum)
+ if (nr_disp >= THROTL_QUANTUM)
break;
}

--
1.8.3.1