We use the constants 0 and 200 in a few places in the mm code when
referring to the min and max swappiness. This patch adds MIN_SWAPPINESS
and MAX_SWAPPINESS #defines to improve clarity. There are no functional
changes.
Signed-off-by: Dan Schatzberg <schatzberg.dan@xxxxxxxxx>
---
include/linux/swap.h | 2 ++
mm/memcontrol.c | 2 +-
mm/vmscan.c | 14 +++++++-------
3 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index f6dd6575b905..e2ab76c25b4a 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -407,6 +407,8 @@ extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
#define MEMCG_RECLAIM_MAY_SWAP (1 << 1)
#define MEMCG_RECLAIM_PROACTIVE (1 << 2)
+#define MIN_SWAPPINESS 0
+#define MAX_SWAPPINESS 200
extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
unsigned long nr_pages,
gfp_t gfp_mask,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b226090fd906..fbe9f02dd206 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4337,7 +4337,7 @@ static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- if (val > 200)
+ if (val > MAX_SWAPPINESS)
return -EINVAL;
if (!mem_cgroup_is_root(memcg))
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9dd8977de5a2..d91963e2d47f 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -183,7 +183,7 @@ struct scan_control {
#endif
/*
- * From 0 .. 200. Higher means more swappy.
+ * From 0 .. MAX_SWAPPINESS. Higher means more swappy.
*/
int vm_swappiness = 60;
@@ -2403,7 +2403,7 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
ap = swappiness * (total_cost + 1);
ap /= anon_cost + 1;
- fp = (200 - swappiness) * (total_cost + 1);
+ fp = (MAX_SWAPPINESS - swappiness) * (total_cost + 1);
fp /= file_cost + 1;
fraction[0] = ap;
@@ -4400,7 +4400,7 @@ static int get_type_to_scan(struct lruvec *lruvec, int swappiness, int *tier_idx
{
int type, tier;
struct ctrl_pos sp, pv;
- int gain[ANON_AND_FILE] = { swappiness, 200 - swappiness };
+ int gain[ANON_AND_FILE] = { swappiness, MAX_SWAPPINESS - swappiness };
/*
* Compare the first tier of anon with that of file to determine which
@@ -4436,7 +4436,7 @@ static int isolate_folios(struct lruvec *lruvec, struct scan_control *sc, int sw
/*
* Try to make the obvious choice first. When anon and file are both
* available from the same generation, interpret swappiness 1 as file
- * first and 200 as anon first.
+ * first and MAX_SWAPPINESS as anon first.
*/
if (!swappiness)
type = LRU_GEN_FILE;
@@ -4444,7 +4444,7 @@ static int isolate_folios(struct lruvec *lruvec, struct scan_control *sc, int sw
type = LRU_GEN_ANON;
else if (swappiness == 1)
type = LRU_GEN_FILE;
- else if (swappiness == 200)
+ else if (swappiness == MAX_SWAPPINESS)
type = LRU_GEN_ANON;
else
type = get_type_to_scan(lruvec, swappiness, &tier);
@@ -5398,9 +5398,9 @@ static int run_cmd(char cmd, int memcg_id, int nid, unsigned long seq,
lruvec = get_lruvec(memcg, nid);
- if (swappiness < 0)
+ if (swappiness < MIN_SWAPPINESS)
swappiness = get_swappiness(lruvec, sc);
- else if (swappiness > 200)
+ else if (swappiness > MAX_SWAPPINESS)
goto done;
switch (cmd) {
--
2.39.3
