[RFC PATCH 15/21] Add relay_add_pages

From: Tom Zanussi
Date: Thu Oct 16 2008 - 02:17:25 EST


---
include/linux/relay.h | 11 +++++++--
kernel/relay.c | 50 +++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/include/linux/relay.h b/include/linux/relay.h
index b23ba90..a33b728 100644
--- a/include/linux/relay.h
+++ b/include/linux/relay.h
@@ -19,6 +19,7 @@
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/kref.h>
+#include <linux/pagevec.h>

/*
* relay channel flags
@@ -164,13 +165,17 @@ extern struct rchan *relay_open(const char *base_filename,
struct rchan_callbacks *cb,
void *private_data,
unsigned long rchan_flags);
-extern void relay_close(struct rchan *chan);
-extern void relay_flush(struct rchan *chan);
-extern void relay_reset(struct rchan *chan);
extern void relay_add_page(struct rchan *chan,
struct page *page,
struct relay_page_callbacks *cb,
void *private_data);
+extern void relay_add_pages(struct rchan *chan,
+ struct pagevec *pages,
+ struct relay_page_callbacks *cb,
+ void *private_data);
+extern void relay_flush(struct rchan *chan);
+extern void relay_close(struct rchan *chan);
+extern void relay_reset(struct rchan *chan);

extern int relay_late_setup_files(struct rchan *chan,
const char *base_filename,
diff --git a/kernel/relay.c b/kernel/relay.c
index e53e729..b27b655 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -19,7 +19,6 @@
#include <linux/module.h>
#include <linux/string.h>
#include <linux/relay.h>
-#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/splice.h>
@@ -117,6 +116,14 @@ static inline void relay_wakeup_readers(struct rchan_buf *buf)
__mod_timer(&buf->timer, jiffies + 1);
}

+static inline void __relay_add_page_nolock(struct rchan_buf *buf,
+ struct relay_page *rpage)
+{
+ list_add_tail(&rpage->list, &buf->pages);
+ buf->nr_pages++;
+ relay_update_filesize(buf, PAGE_SIZE);
+}
+
/**
* __relay_add_page - add a relay page to relay
* @buf: the buffer struct
@@ -127,9 +134,7 @@ static void __relay_add_page(struct rchan_buf *buf, struct relay_page *rpage)
unsigned long flags;

spin_lock_irqsave(&buf->lock, flags);
- list_add_tail(&rpage->list, &buf->pages);
- buf->nr_pages++;
- relay_update_filesize(buf, PAGE_SIZE);
+ __relay_add_page_nolock(buf, rpage);
spin_unlock_irqrestore(&buf->lock, flags);

relay_wakeup_readers(buf);
@@ -165,6 +170,43 @@ void relay_add_page(struct rchan *chan,
EXPORT_SYMBOL_GPL(relay_add_page);

/**
+ * relay_add_pages - add pages to relay
+ * @buf: the buffer struct
+ * @page: struct page
+ *
+ * relay now owns the page.
+ */
+void relay_add_pages(struct rchan *chan,
+ struct pagevec *pages,
+ struct relay_page_callbacks *cb,
+ void *private_data)
+{
+ struct relay_page *rpage;
+ struct rchan_buf *buf;
+ unsigned long flags;
+ int i, nr_pages = pagevec_count(pages);
+
+ buf = chan->buf[get_cpu()];
+ spin_lock_irqsave(&buf->lock, flags);
+ for (i = 0; i < nr_pages; i++) {
+ rpage = __relay_get_rpage(buf);
+
+ if (likely(rpage)) {
+ rpage->page = pages->pages[i];
+ set_page_private(rpage->page, (unsigned long)buf);
+ rpage->cb = cb;
+ rpage->private_data = private_data;
+ __relay_add_page_nolock(buf, rpage);
+ }
+ }
+ spin_unlock_irqrestore(&buf->lock, flags);
+ put_cpu();
+
+ relay_wakeup_readers(buf);
+}
+EXPORT_SYMBOL_GPL(relay_add_pages);
+
+/**
* relay_create_buf - allocate and initialize a channel buffer
* @chan: the relay channel
*
--
1.5.3.5



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/