Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit dcb4e2d9 authored by Wanpeng Li's avatar Wanpeng Li Committed by Greg Kroah-Hartman
Browse files

staging: zcache: introduce zero filled pages handler 



Introduce zero-filled pages handler to capture and handle zero pages.

Acked-by: default avatarDan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: default avatarWanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ad3c025b

drivers/staging/zcache/zcache-main.c

+26 −0
Original line number Diff line number Diff line
@@ -277,6 +277,32 @@ static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool) 
	kmem_cache_free(zcache_obj_cache, obj);

}



static bool page_is_zero_filled(void *ptr)

{

	unsigned int pos;

	unsigned long *page;



	page = (unsigned long *)ptr;



	for (pos = 0; pos < PAGE_SIZE / sizeof(*page); pos++) {

		if (page[pos])

			return false;

	}



	return true;

}



static void handle_zero_filled_page(void *page)

{

	void *user_mem;



	user_mem = kmap_atomic(page);

	memset(user_mem, 0, PAGE_SIZE);

	kunmap_atomic(user_mem);



	flush_dcache_page(page);

}



static struct tmem_hostops zcache_hostops = {

	.obj_alloc = zcache_obj_alloc,

	.obj_free = zcache_obj_free,