From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx188.postini.com [74.125.245.188]) by kanga.kvack.org (Postfix) with SMTP id EBE646B0036 for ; Mon, 1 Apr 2013 22:46:37 -0400 (EDT) Received: from /spool/local by e28smtp01.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 2 Apr 2013 08:12:26 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id BD7BEE0055 for ; Tue, 2 Apr 2013 08:18:09 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r322kP0C66256976 for ; Tue, 2 Apr 2013 08:16:25 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r322kRiP023415 for ; Tue, 2 Apr 2013 02:46:27 GMT From: Wanpeng Li Subject: [PATCH v5 1/8] staging: zcache: introduce zero-filled pages handler Date: Tue, 2 Apr 2013 10:46:13 +0800 Message-Id: <1364870780-16296-2-git-send-email-liwanp@linux.vnet.ibm.com> In-Reply-To: <1364870780-16296-1-git-send-email-liwanp@linux.vnet.ibm.com> References: <1364870780-16296-1-git-send-email-liwanp@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Greg Kroah-Hartman Cc: Andrew Morton , Dan Magenheimer , Seth Jennings , Konrad Rzeszutek Wilk , Minchan Kim , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven , Fengguang Wu , Wanpeng Li Introduce zero-filled pages handler to capture and handle zero pages. Acked-by: Dan Magenheimer Signed-off-by: Wanpeng Li --- drivers/staging/zcache/zcache-main.c | 27 +++++++++++++++++++++++++++ 1 files changed, 27 insertions(+), 0 deletions(-) diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c index 7a6dd96..a0578d1 100644 --- a/drivers/staging/zcache/zcache-main.c +++ b/drivers/staging/zcache/zcache-main.c @@ -277,6 +277,33 @@ 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 *p) +{ + void *user_mem; + struct page *page = (struct page *)p; + + 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, -- 1.7.7.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org