[PATCH v2 06/20] mm/zsmalloc: convert create_page_chain() and its users to use zpdesc

alexs
2024-07-03T04:01:31Z

From: Alex Shi <alexs@kernel.org>

Introduce a few helper functions for conversion to convert create_page_chain()
to use zpdesc, then use zpdesc in replace_sub_page() too.

Originally-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Alex Shi <alexs@kernel.org>
---
mm/zpdesc.h | 6 +++
mm/zsmalloc.c | 115 +++++++++++++++++++++++++++++++++-----------------
2 files changed, 82 insertions(+), 39 deletions(-)

diff --git a/mm/zpdesc.h b/mm/zpdesc.h
index 96b9ce80ea49..a2e320f24dd4 100644
--- a/mm/zpdesc.h
+++ b/mm/zpdesc.h
@@ -100,4 +100,10 @@ static inline struct zpdesc *pfn_zpdesc(unsigned long pfn)
{
return page_zpdesc(pfn_to_page(pfn));
}
+
+static inline void __zpdesc_set_movable(struct zpdesc *zpdesc,
+ const struct movable_operations *mops)
+{
+ __SetPageMovable(zpdesc_page(zpdesc), mops);
+}
#endif
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index bbc165cb587d..a8f390beeab8 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -248,6 +248,41 @@ static inline void *zpdesc_kmap_atomic(struct zpdesc *zpdesc)
return kmap_atomic(zpdesc_page(zpdesc));
}

+static inline void zpdesc_set_zspage(struct zpdesc *zpdesc,
+ struct zspage *zspage)
+{
+ zpdesc->zspage = zspage;
+}
+
+static inline void zpdesc_set_first(struct zpdesc *zpdesc)
+{
+ SetPagePrivate(zpdesc_page(zpdesc));
+}
+
+static inline void zpdesc_inc_zone_page_state(struct zpdesc *zpdesc)
+{
+ inc_zone_page_state(zpdesc_page(zpdesc), NR_ZSPAGES);
+}
+
+static inline void zpdesc_dec_zone_page_state(struct zpdesc *zpdesc)
+{
+ dec_zone_page_state(zpdesc_page(zpdesc), NR_ZSPAGES);
+}
+
+static inline struct zpdesc *alloc_zpdesc(gfp_t gfp)
+{
+ struct page *page = alloc_page(gfp);
+
+ return page_zpdesc(page);
+}
+
+static inline void free_zpdesc(struct zpdesc *zpdesc)
+{
+ struct page *page = zpdesc_page(zpdesc);
+
+ __free_page(page);
+}
+
struct zspage {
struct {
unsigned int huge:HUGE_BITS;
@@ -954,35 +989,35 @@ static void init_zspage(struct size_class *class, struct zspage *zspage)
}

static void create_page_chain(struct size_class *class, struct zspage *zspage,
- struct page *pages[])
+ struct zpdesc *zpdescs[])
{
int i;
- struct page *page;
- struct page *prev_page = NULL;
- int nr_pages = class->pages_per_zspage;
+ struct zpdesc *zpdesc;
+ struct zpdesc *prev_zpdesc = NULL;
+ int nr_zpdescs = class->pages_per_zspage;

/*
* Allocate individual pages and link them together as:
- * 1. all pages are linked together using page->index
- * 2. each sub-page point to zspage using page->private
+ * 1. all pages are linked together using zpdesc->next
+ * 2. each sub-page point to zspage using zpdesc->zspage
*
- * we set PG_private to identify the first page (i.e. no other sub-page
+ * we set PG_private to identify the first zpdesc (i.e. no other zpdesc
* has this flag set).
*/
- for (i = 0; i < nr_pages; i++) {
- page = pages[i];
- set_page_private(page, (unsigned long)zspage);
- page->index = 0;
+ for (i = 0; i < nr_zpdescs; i++) {
+ zpdesc = zpdescs[i];
+ zpdesc_set_zspage(zpdesc, zspage);
+ zpdesc->next = NULL;
if (i == 0) {
- zspage->first_zpdesc = page_zpdesc(page);
- SetPagePrivate(page);
+ zspage->first_zpdesc = zpdesc;
+ zpdesc_set_first(zpdesc);
if (unlikely(class->objs_per_zspage == 1 &&
class->pages_per_zspage == 1))
SetZsHugePage(zspage);
} else {
- prev_page->index = (unsigned long)page;
+ prev_zpdesc->next = zpdesc;
}
- prev_page = page;
+ prev_zpdesc = zpdesc;
}
}

@@ -994,7 +1029,7 @@ static struct zspage *alloc_zspage(struct zs_pool *pool,
gfp_t gfp)
{
int i;
- struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE];
+ struct zpdesc *zpdescs[ZS_MAX_PAGES_PER_ZSPAGE];
struct zspage *zspage = cache_alloc_zspage(pool, gfp);

if (!zspage)
@@ -1004,25 +1039,25 @@ static struct zspage *alloc_zspage(struct zs_pool *pool,
migrate_lock_init(zspage);

for (i = 0; i < class->pages_per_zspage; i++) {
- struct page *page;
+ struct zpdesc *zpdesc;

- page = alloc_page(gfp);
- if (!page) {
+ zpdesc = alloc_zpdesc(gfp);
+ if (!zpdesc) {
while (--i >= 0) {
- dec_zone_page_state(pages[i], NR_ZSPAGES);
- __ClearPageZsmalloc(pages[i]);
- __free_page(pages[i]);
+ zpdesc_dec_zone_page_state(zpdescs[i]);
+ __ClearPageZsmalloc(zpdesc_page(zpdescs[i]));
+ free_zpdesc(zpdescs[i]);
}
cache_free_zspage(pool, zspage);
return NULL;
}
- __SetPageZsmalloc(page);
+ __SetPageZsmalloc(zpdesc_page(zpdesc));

- inc_zone_page_state(page, NR_ZSPAGES);
- pages[i] = page;
+ zpdesc_inc_zone_page_state(zpdesc);
+ zpdescs[i] = zpdesc;
}

- create_page_chain(class, zspage, pages);
+ create_page_chain(class, zspage, zpdescs);
init_zspage(class, zspage);
zspage->pool = pool;
zspage->class = class->index;
@@ -1753,26 +1788,28 @@ static void migrate_write_unlock(struct zspage *zspage)
static const struct movable_operations zsmalloc_mops;

static void replace_sub_page(struct size_class *class, struct zspage *zspage,
- struct page *newpage, struct page *oldpage)
+ struct zpdesc *newzpdesc, struct zpdesc *oldzpdesc)
{
- struct page *page;
- struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE] = {NULL, };
+ struct zpdesc *zpdesc;
+ struct zpdesc *zpdescs[ZS_MAX_PAGES_PER_ZSPAGE] = {NULL, };
+ unsigned int first_obj_offset;
int idx = 0;

- page = get_first_page(zspage);
+ zpdesc = get_first_zpdesc(zspage);
do {
- if (page == oldpage)
- pages[idx] = newpage;
+ if (zpdesc == oldzpdesc)
+ zpdescs[idx] = newzpdesc;
else
- pages[idx] = page;
+ zpdescs[idx] = zpdesc;
idx++;
- } while ((page = get_next_page(page)) != NULL);
+ } while ((zpdesc = get_next_zpdesc(zpdesc)) != NULL);

- create_page_chain(class, zspage, pages);
- set_first_obj_offset(newpage, get_first_obj_offset(oldpage));
+ create_page_chain(class, zspage, zpdescs);
+ first_obj_offset = get_first_obj_offset(zpdesc_page(oldzpdesc));
+ set_first_obj_offset(zpdesc_page(newzpdesc), first_obj_offset);
if (unlikely(ZsHugePage(zspage)))
- newpage->index = oldpage->index;
- __SetPageMovable(newpage, &zsmalloc_mops);
+ newzpdesc->handle = oldzpdesc->handle;
+ __zpdesc_set_movable(newzpdesc, &zsmalloc_mops);
}

static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
@@ -1845,7 +1882,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page,
}
kunmap_atomic(s_addr);

- replace_sub_page(class, zspage, newpage, page);
+ replace_sub_page(class, zspage, page_zpdesc(newpage), page_zpdesc(page));
/*
* Since we complete the data copy and set up new zspage structure,
* it's okay to release migration_lock.
--
2.43.0