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From: Wanpeng Li <liwanp@linux.vnet.ibm.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Dan Magenheimer <dan.magenheimer@oracle.com>,
	Seth Jennings <sjenning@linux.vnet.ibm.com>,
	Konrad Rzeszutek Wilk <konrad@darnok.org>,
	Minchan Kim <minchan@kernel.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Wanpeng Li <liwanp@linux.vnet.ibm.com>
Subject: [PATCH v4 1/8] staging: zcache: introduce zero-filled pages handler
Date: Tue, 19 Mar 2013 17:25:43 +0800	[thread overview]
Message-ID: <1363685150-18303-2-git-send-email-liwanp@linux.vnet.ibm.com> (raw)
In-Reply-To: <1363685150-18303-1-git-send-email-liwanp@linux.vnet.ibm.com>

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>
---
 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 328898e..d73dd4b 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -460,6 +460,32 @@ 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,
-- 
1.7.7.6


WARNING: multiple messages have this Message-ID (diff)
From: Wanpeng Li <liwanp@linux.vnet.ibm.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Dan Magenheimer <dan.magenheimer@oracle.com>,
	Seth Jennings <sjenning@linux.vnet.ibm.com>,
	Konrad Rzeszutek Wilk <konrad@darnok.org>,
	Minchan Kim <minchan@kernel.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Wanpeng Li <liwanp@linux.vnet.ibm.com>
Subject: [PATCH v4 1/8] staging: zcache: introduce zero-filled pages handler
Date: Tue, 19 Mar 2013 17:25:43 +0800	[thread overview]
Message-ID: <1363685150-18303-2-git-send-email-liwanp@linux.vnet.ibm.com> (raw)
In-Reply-To: <1363685150-18303-1-git-send-email-liwanp@linux.vnet.ibm.com>

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>
---
 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 328898e..d73dd4b 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -460,6 +460,32 @@ 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,
-- 
1.7.7.6

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  reply	other threads:[~2013-03-19  9:26 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-19  9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
2013-03-19  9:25 ` Wanpeng Li
2013-03-19  9:25 ` Wanpeng Li [this message]
2013-03-19  9:25   ` [PATCH v4 1/8] staging: zcache: introduce zero-filled pages handler Wanpeng Li
2013-03-23 19:31   ` Geert Uytterhoeven
2013-03-23 19:31     ` Geert Uytterhoeven
2013-03-19  9:25 ` [PATCH v4 2/8] staging: zcache: zero-filled pages awareness Wanpeng Li
2013-03-19  9:25   ` Wanpeng Li
2013-03-20 10:30   ` Bob Liu
2013-03-20 10:30     ` Bob Liu
2013-03-20 10:43     ` Wanpeng Li
2013-03-20 10:43     ` Wanpeng Li
2013-03-19  9:25 ` [PATCH v4 3/8] staging: zcache: handle zcache_[eph|pers]_zpages for zero-filled page Wanpeng Li
2013-03-19  9:25   ` Wanpeng Li
2013-03-19  9:25 ` [PATCH v4 4/8] staging: zcache: fix pers_pageframes|_max aren't exported in debugfs Wanpeng Li
2013-03-19  9:25   ` Wanpeng Li
2013-03-19  9:25 ` [PATCH v4 5/8] staging: zcache: fix zcache writeback " Wanpeng Li
2013-03-19  9:25   ` Wanpeng Li
2013-03-19  9:25 ` [PATCH v4 6/8] staging: zcache: fix static variables defined in debug.h but used in mutiple C files Wanpeng Li
2013-03-19  9:25   ` Wanpeng Li
2013-03-19  9:25 ` [PATCH v4 7/8] staging: zcache: introduce zero-filled page stat count Wanpeng Li
2013-03-19  9:25   ` Wanpeng Li
2013-03-19  9:25 ` [PATCH v4 8/8] staging: zcache: clean TODO list Wanpeng Li
2013-03-19  9:25   ` Wanpeng Li
2013-03-19 23:34 ` [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Ric Mason
2013-03-19 23:34   ` Ric Mason

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