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| author | Wanpeng Li <liwanp@linux.vnet.ibm.com> | 2013-03-15 10:34:16 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-18 17:24:35 -0700 |
| commit | dcb4e2d9bb4e3b6ad05bc513a237a87e46952341 (patch) | |
| tree | ad6765b07229c7246cd397bcb0790fafcc2c3e9c | |
| parent | ad3c025b35832f9634523651d27dbf1233570976 (diff) | |
staging: zcache: introduce zero filled pages handler
Introduce zero-filled pages handler to capture and handle zero pages.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/zcache/zcache-main.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c index 7a6dd966931b..86ead8d96796 100644 --- a/drivers/staging/zcache/zcache-main.c +++ b/drivers/staging/zcache/zcache-main.c @@ -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, |