* [PATCH] mm: workingset: define macro WORKINGSET_SHIFT
@ 2021-06-24 12:23 Miaohe Lin
0 siblings, 0 replies; only message in thread
From: Miaohe Lin @ 2021-06-24 12:23 UTC (permalink / raw)
To: akpm; +Cc: linux-kernel, linux-mm, linmiaohe
The magic number 1 is used in several places in workingset.c. Define a
macro WORKINGSET_SHIFT for it to improve code readability.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/workingset.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/mm/workingset.c b/mm/workingset.c
index 9d3d2b4ce44d..cf8bb34fb321 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -168,8 +168,10 @@
* refault distance will immediately activate the refaulting page.
*/
+#define WORKINGSET_SHIFT 1
#define EVICTION_SHIFT ((BITS_PER_LONG - BITS_PER_XA_VALUE) + \
- 1 + NODES_SHIFT + MEM_CGROUP_ID_SHIFT)
+ WORKINGSET_SHIFT + NODES_SHIFT + \
+ MEM_CGROUP_ID_SHIFT)
#define EVICTION_MASK (~0UL >> EVICTION_SHIFT)
/*
@@ -189,7 +191,7 @@ static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction,
eviction &= EVICTION_MASK;
eviction = (eviction << MEM_CGROUP_ID_SHIFT) | memcgid;
eviction = (eviction << NODES_SHIFT) | pgdat->node_id;
- eviction = (eviction << 1) | workingset;
+ eviction = (eviction << WORKINGSET_SHIFT) | workingset;
return xa_mk_value(eviction);
}
@@ -201,8 +203,8 @@ static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat,
int memcgid, nid;
bool workingset;
- workingset = entry & 1;
- entry >>= 1;
+ workingset = entry & ((1UL << WORKINGSET_SHIFT) - 1);
+ entry >>= WORKINGSET_SHIFT;
nid = entry & ((1UL << NODES_SHIFT) - 1);
entry >>= NODES_SHIFT;
memcgid = entry & ((1UL << MEM_CGROUP_ID_SHIFT) - 1);
--
2.23.0
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2021-06-24 12:23 [PATCH] mm: workingset: define macro WORKINGSET_SHIFT Miaohe Lin
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