zsmalloc: move huge compressed obj from page to zspage

The flag aims for zspage, not per page.  Let's move it to zspage.

Link: https://lkml.kernel.org/r/20211115185909.3949505-6-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 5c72fd5..6483062 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -121,6 +121,7 @@
 #define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS)
 #define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1)
 
+#define HUGE_BITS      1
 #define FULLNESS_BITS  2
 #define CLASS_BITS     8
 #define ISOLATED_BITS  3
@@ -213,22 +214,6 @@ struct size_class {
        struct zs_size_stat stats;
 };
 
-/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */
-static void SetPageHugeObject(struct page *page)
-{
-       SetPageOwnerPriv1(page);
-}
-
-static void ClearPageHugeObject(struct page *page)
-{
-       ClearPageOwnerPriv1(page);
-}
-
-static int PageHugeObject(struct page *page)
-{
-       return PageOwnerPriv1(page);
-}
-
 /*
  * Placed within free objects to form a singly linked list.
  * For every zspage, zspage->freeobj gives head of this list.
@@ -278,6 +263,7 @@ struct zs_pool {
 
 struct zspage {
        struct {
+               unsigned int huge:HUGE_BITS;
                unsigned int fullness:FULLNESS_BITS;
                unsigned int class:CLASS_BITS + 1;
                unsigned int isolated:ISOLATED_BITS;
@@ -298,6 +284,17 @@ struct mapping_area {
        enum zs_mapmode vm_mm; /* mapping mode */
 };
 
+/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */
+static void SetZsHugePage(struct zspage *zspage)
+{
+       zspage->huge = 1;
+}
+
+static bool ZsHugePage(struct zspage *zspage)
+{
+       return zspage->huge;
+}
+
 #ifdef CONFIG_COMPACTION
 static int zs_register_migration(struct zs_pool *pool);
 static void zs_unregister_migration(struct zs_pool *pool);
@@ -830,7 +827,9 @@ static struct zspage *get_zspage(struct page *page)
 
 static struct page *get_next_page(struct page *page)
 {
-       if (unlikely(PageHugeObject(page)))
+       struct zspage *zspage = get_zspage(page);
+
+       if (unlikely(ZsHugePage(zspage)))
                return NULL;
 
        return (struct page *)page->index;
@@ -880,8 +879,9 @@ static unsigned long handle_to_obj(unsigned long handle)
 static bool obj_allocated(struct page *page, void *obj, unsigned long *phandle)
 {
        unsigned long handle;
+       struct zspage *zspage = get_zspage(page);
 
-       if (unlikely(PageHugeObject(page))) {
+       if (unlikely(ZsHugePage(zspage))) {
                VM_BUG_ON_PAGE(!is_first_page(page), page);
                handle = page->index;
        } else
@@ -920,7 +920,6 @@ static void reset_page(struct page *page)
        ClearPagePrivate(page);
        set_page_private(page, 0);
        page_mapcount_reset(page);
-       ClearPageHugeObject(page);
        page->index = 0;
 }
 
@@ -1062,7 +1061,7 @@ static void create_page_chain(struct size_class *class, struct zspage *zspage,
                        SetPagePrivate(page);
                        if (unlikely(class->objs_per_zspage == 1 &&
                                        class->pages_per_zspage == 1))
-                               SetPageHugeObject(page);
+                               SetZsHugePage(zspage);
                } else {
                        prev_page->index = (unsigned long)page;
                }
@@ -1307,7 +1306,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle,
 
        ret = __zs_map_object(area, pages, off, class->size);
 out:
-       if (likely(!PageHugeObject(page)))
+       if (likely(!ZsHugePage(zspage)))
                ret += ZS_HANDLE_SIZE;
 
        return ret;
@@ -1395,7 +1394,7 @@ static unsigned long obj_malloc(struct zs_pool *pool,
        vaddr = kmap_atomic(m_page);
        link = (struct link_free *)vaddr + m_offset / sizeof(*link);
        set_freeobj(zspage, link->next >> OBJ_TAG_BITS);
-       if (likely(!PageHugeObject(m_page)))
+       if (likely(!ZsHugePage(zspage)))
                /* record handle in the header of allocated chunk */
                link->handle = handle;
        else
@@ -1496,7 +1495,10 @@ static void obj_free(int class_size, unsigned long obj)
 
        /* Insert this object in containing zspage's freelist */
        link = (struct link_free *)(vaddr + f_offset);
-       link->next = get_freeobj(zspage) << OBJ_TAG_BITS;
+       if (likely(!ZsHugePage(zspage)))
+               link->next = get_freeobj(zspage) << OBJ_TAG_BITS;
+       else
+               f_page->index = 0;
        kunmap_atomic(vaddr);
        set_freeobj(zspage, f_objidx);
        mod_zspage_inuse(zspage, -1);
@@ -1867,7 +1869,7 @@ static void replace_sub_page(struct size_class *class, struct zspage *zspage,
 
        create_page_chain(class, zspage, pages);
        set_first_obj_offset(newpage, get_first_obj_offset(oldpage));
-       if (unlikely(PageHugeObject(oldpage)))
+       if (unlikely(ZsHugePage(zspage)))
                newpage->index = oldpage->index;
        __SetPageMovable(newpage, page_mapping(oldpage));
 }