Commit 3ae92ac2 authored by Minchan Kim's avatar Minchan Kim Committed by Linus Torvalds
Browse files

zsmalloc: introduce obj_allocated 

The usage pattern for obj_to_head is to check whether the zpage is
allocated or not.  Thus, introduce obj_allocated.

Link: https://lkml.kernel.org/r/20211115185909.3949505-5-minchan@kernel.org


Signed-off-by: default avatarMinchan Kim <minchan@kernel.org>
Acked-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: default avatarSebastian 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0a5f079b

mm/zsmalloc.c

+16 −17
Original line number Diff line number Diff line
@@ -877,13 +877,21 @@ static unsigned long handle_to_obj(unsigned long handle) 
	return *(unsigned long *)handle;

}



static unsigned long obj_to_head(struct page *page, void *obj)

static bool obj_allocated(struct page *page, void *obj, unsigned long *phandle)

{

	unsigned long handle;



	if (unlikely(PageHugeObject(page))) {

		VM_BUG_ON_PAGE(!is_first_page(page), page);

		return page->index;

		handle = page->index;

	} else

		return *(unsigned long *)obj;

		handle = *(unsigned long *)obj;



	if (!(handle & OBJ_ALLOCATED_TAG))

		return false;



	*phandle = handle & ~OBJ_ALLOCATED_TAG;

	return true;

}



static inline int testpin_tag(unsigned long handle)
@@ -1606,7 +1614,6 @@ static void zs_object_copy(struct size_class *class, unsigned long dst, 
static unsigned long find_alloced_obj(struct size_class *class,

					struct page *page, int *obj_idx)

{

	unsigned long head;

	int offset = 0;

	int index = *obj_idx;

	unsigned long handle = 0;
@@ -1616,9 +1623,7 @@ static unsigned long find_alloced_obj(struct size_class *class, 
	offset += class->size * index;



	while (offset < PAGE_SIZE) {

		head = obj_to_head(page, addr + offset);

		if (head & OBJ_ALLOCATED_TAG) {

			handle = head & ~OBJ_ALLOCATED_TAG;

		if (obj_allocated(page, addr + offset, &handle)) {

			if (trypin_tag(handle))

				break;

			handle = 0;
@@ -1928,7 +1933,7 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage, 
	struct page *dummy;

	void *s_addr, *d_addr, *addr;

	int offset, pos;

	unsigned long handle, head;

	unsigned long handle;

	unsigned long old_obj, new_obj;

	unsigned int obj_idx;

	int ret = -EAGAIN;
@@ -1964,9 +1969,7 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage, 
	pos = offset;

	s_addr = kmap_atomic(page);

	while (pos < PAGE_SIZE) {

		head = obj_to_head(page, s_addr + pos);

		if (head & OBJ_ALLOCATED_TAG) {

			handle = head & ~OBJ_ALLOCATED_TAG;

		if (obj_allocated(page, s_addr + pos, &handle)) {

			if (!trypin_tag(handle))

				goto unpin_objects;

		}
@@ -1982,9 +1985,7 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage, 


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

					addr += class->size) {

		head = obj_to_head(page, addr);

		if (head & OBJ_ALLOCATED_TAG) {

			handle = head & ~OBJ_ALLOCATED_TAG;

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

			BUG_ON(!testpin_tag(handle));



			old_obj = handle_to_obj(handle);
@@ -2029,9 +2030,7 @@ static int zs_page_migrate(struct address_space *mapping, struct page *newpage, 
unpin_objects:

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

						addr += class->size) {

		head = obj_to_head(page, addr);

		if (head & OBJ_ALLOCATED_TAG) {

			handle = head & ~OBJ_ALLOCATED_TAG;

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

			BUG_ON(!testpin_tag(handle));

			unpin_tag(handle);

		}