Commit 3ebc57f4 authored by Miaohe Lin's avatar Miaohe Lin Committed by Linus Torvalds
Browse files

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@huawei.com


Signed-off-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 764c04a9

mm/workingset.c

+6 −4
Original line number Diff line number Diff line
@@ -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);