Commit 68721300 authored by Harry Yoo's avatar Harry Yoo Committed by Andrew Morton
Browse files

mm/zsmalloc: add two helpers for zs_page_migrate() and make it use zpdesc 

To convert page to zpdesc in zs_page_migrate(), we added
zpdesc_is_isolated()/zpdesc_zone() helpers.  No functional change.
Link: https://lkml.kernel.org/r/20241216150450.1228021-11-42.hyeyoo@gmail.com


Signed-off-by: default avatarHyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: default avatarAlex Shi <alexs@kernel.org>
Acked-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 4e04d10c

mm/zpdesc.h

+11 −0
Original line number Diff line number Diff line
@@ -154,4 +154,15 @@ static inline void __zpdesc_set_movable(struct zpdesc *zpdesc, 
{

	__SetPageMovable(zpdesc_page(zpdesc), mops);

}



static inline bool zpdesc_is_isolated(struct zpdesc *zpdesc)

{

	return PageIsolated(zpdesc_page(zpdesc));

}



static inline struct zone *zpdesc_zone(struct zpdesc *zpdesc)

{

	return page_zone(zpdesc_page(zpdesc));

}



#endif

mm/zsmalloc.c

+16 −14
Original line number Diff line number Diff line
@@ -1796,19 +1796,21 @@ static int zs_page_migrate(struct page *newpage, struct page *page, 
	struct size_class *class;

	struct zspage *zspage;

	struct zpdesc *dummy;

	struct zpdesc *newzpdesc = page_zpdesc(newpage);

	struct zpdesc *zpdesc = page_zpdesc(page);

	void *s_addr, *d_addr, *addr;

	unsigned int offset;

	unsigned long handle;

	unsigned long old_obj, new_obj;

	unsigned int obj_idx;



	VM_BUG_ON_PAGE(!PageIsolated(page), page);

	VM_BUG_ON_PAGE(!zpdesc_is_isolated(zpdesc), zpdesc_page(zpdesc));



	/* We're committed, tell the world that this is a Zsmalloc page. */

	__SetPageZsmalloc(newpage);

	__SetPageZsmalloc(zpdesc_page(newzpdesc));



	/* The page is locked, so this pointer must remain valid */

	zspage = get_zspage(page);

	zspage = get_zspage(zpdesc_page(zpdesc));

	pool = zspage->pool;



	/*
@@ -1825,30 +1827,30 @@ static int zs_page_migrate(struct page *newpage, struct page *page, 
	/* the migrate_write_lock protects zpage access via zs_map_object */

	migrate_write_lock(zspage);



	offset = get_first_obj_offset(page);

	s_addr = kmap_local_page(page);

	offset = get_first_obj_offset(zpdesc_page(zpdesc));

	s_addr = kmap_local_zpdesc(zpdesc);



	/*

	 * Here, any user cannot access all objects in the zspage so let's move.

	 */

	d_addr = kmap_local_page(newpage);

	d_addr = kmap_local_zpdesc(newzpdesc);

	copy_page(d_addr, s_addr);

	kunmap_local(d_addr);



	for (addr = s_addr + offset; addr < s_addr + PAGE_SIZE;

					addr += class->size) {

		if (obj_allocated(page_zpdesc(page), addr, &handle)) {

		if (obj_allocated(zpdesc, addr, &handle)) {



			old_obj = handle_to_obj(handle);

			obj_to_location(old_obj, &dummy, &obj_idx);

			new_obj = (unsigned long)location_to_obj(newpage,

			new_obj = (unsigned long)location_to_obj(zpdesc_page(newzpdesc),

								obj_idx);

			record_obj(handle, new_obj);

		}

	}

	kunmap_local(s_addr);



	replace_sub_page(class, zspage, page_zpdesc(newpage), page_zpdesc(page));

	replace_sub_page(class, zspage, newzpdesc, zpdesc);

	/*

	 * Since we complete the data copy and set up new zspage structure,

	 * it's okay to release migration_lock.
@@ -1857,14 +1859,14 @@ static int zs_page_migrate(struct page *newpage, struct page *page, 
	spin_unlock(&class->lock);

	migrate_write_unlock(zspage);



	get_page(newpage);

	if (page_zone(newpage) != page_zone(page)) {

		dec_zone_page_state(page, NR_ZSPAGES);

		inc_zone_page_state(newpage, NR_ZSPAGES);

	zpdesc_get(newzpdesc);

	if (zpdesc_zone(newzpdesc) != zpdesc_zone(zpdesc)) {

		zpdesc_dec_zone_page_state(zpdesc);

		zpdesc_inc_zone_page_state(newzpdesc);

	}



	reset_page(page);

	put_page(page);

	zpdesc_put(zpdesc);



	return MIGRATEPAGE_SUCCESS;

}