From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm: workingset: define macro WORKINGSET_SHIFT The magic number 1 is used in several places in workingset.c. Define a macro WORKINGSET_SHIFT for it to improve code readability. Link: https://lkml.kernel.org/r/20210624122307.1759342-1-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/workingset.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/mm/workingset.c~mm-workingset-define-macro-workingset_shift +++ a/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 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 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); _
