mm/zsmalloc: remove unused zspage->isolated

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.

Link: https://lkml.kernel.org/r/20240219-b4-szmalloc-migrate-v1-3-34cd49c6545b@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index f2ae7d4c6f216fbb4102b87f14a02824e400ad0c..a48f4651d143bca99615777c7a68359c3f889d2c 100644 (file)
--- 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 = {