[PATCH RESEND 3/3] mm/zsmalloc: remove unused zspage->isolated

Chengming Zhou
2024-02-20T11:37:36Z

From: Chengming Zhou <zhouchengming@bytedance.com>

The zspage->isolated is not used anywhere, we don't need to maintain it,
which needs to hold the heavy pool lock to update it, so just remove it.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
---
mm/zsmalloc.c | 32 --------------------------------
1 file changed, 32 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index f2ae7d4c6f21..a48f4651d143 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -116,7 +116,6 @@
#define HUGE_BITS 1
#define FULLNESS_BITS 4
#define CLASS_BITS 8
-#define ISOLATED_BITS 5
#define MAGIC_VAL_BITS 8

#define MAX(a, b) ((a) >= (b) ? (a) : (b))
@@ -246,7 +245,6 @@ struct zspage {
unsigned int huge:HUGE_BITS;
unsigned int fullness:FULLNESS_BITS;
unsigned int class:CLASS_BITS + 1;
- unsigned int isolated:ISOLATED_BITS;
unsigned int magic:MAGIC_VAL_BITS;
};
unsigned int inuse;
@@ -1732,17 +1730,6 @@ static void migrate_write_unlock(struct zspage *zspage)
}

#ifdef CONFIG_COMPACTION
-/* Number of isolated subpage for *page migration* in this zspage */
-static void inc_zspage_isolation(struct zspage *zspage)
-{
- zspage->isolated++;
-}
-
-static void dec_zspage_isolation(struct zspage *zspage)
-{
- VM_BUG_ON(zspage->isolated == 0);
- zspage->isolated--;
-}

static const struct movable_operations zsmalloc_mops;

@@ -1771,21 +1758,12 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage,

static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
{
- struct zs_pool *pool;
- struct zspage *zspage;
-
/*
* Page is locked so zspage couldn't be destroyed. For detail, look at
* lock_zspage in free_zspage.
*/
VM_BUG_ON_PAGE(PageIsolated(page), page);

- zspage = get_zspage(page);
- pool = zspage->pool;
- spin_lock(&pool->lock);
- inc_zspage_isolation(zspage);
- spin_unlock(&pool->lock);
-
return true;
}

@@ -1850,7 +1828,6 @@ static int zs_page_migrate(struct page *newpage, struct page *page,
kunmap_atomic(s_addr);

replace_sub_page(class, zspage, newpage, page);
- dec_zspage_isolation(zspage);
/*
* Since we complete the data copy and set up new zspage structure,
* it's okay to release the pool's lock.
@@ -1872,16 +1849,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page,

static void zs_page_putback(struct page *page)
{
- struct zs_pool *pool;
- struct zspage *zspage;
-
VM_BUG_ON_PAGE(!PageIsolated(page), page);
-
- zspage = get_zspage(page);
- pool = zspage->pool;
- spin_lock(&pool->lock);
- dec_zspage_isolation(zspage);
- spin_unlock(&pool->lock);
}

static const struct movable_operations zsmalloc_mops = {

--
b4 0.10.1