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authorJens Axboe <axboe@suse.de>2006-04-11 13:52:47 +0200
committerJens Axboe <axboe@suse.de>2006-04-11 13:52:47 +0200
commit7480a90435673b4c717b6caf1350ec577d5f1adf (patch)
tree16470986faf89380450da76a928c7856e5a850a1
parentb92ce55893745e011edae70830b8bc863be881f9 (diff)
[PATCH] splice: speedup __generic_file_splice_read
Using find_get_page() is a lot faster than find_or_create_page(). This gets splice a lot closer to sendfile() for fd -> socket transfers. Signed-off-by: Jens Axboe <axboe@suse.de>
-rw-r--r--fs/splice.c74
1 files changed, 63 insertions, 11 deletions
diff --git a/fs/splice.c b/fs/splice.c
index c47b561edac0..e30743c2c06a 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -240,7 +240,7 @@ __generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe,
struct page *pages[PIPE_BUFFERS];
struct page *page;
pgoff_t index;
- int i;
+ int i, error;
index = in->f_pos >> PAGE_CACHE_SHIFT;
offset = in->f_pos & ~PAGE_CACHE_MASK;
@@ -260,32 +260,84 @@ __generic_file_splice_read(struct file *in, struct pipe_inode_info *pipe,
/*
* now fill in the holes
*/
+ error = 0;
for (i = 0; i < nr_pages; i++, index++) {
+find_page:
/*
- * no page there, look one up / create it
+ * lookup the page for this index
*/
- page = find_or_create_page(mapping, index,
- mapping_gfp_mask(mapping));
- if (!page)
- break;
+ page = find_get_page(mapping, index);
+ if (!page) {
+ /*
+ * If in nonblock mode then dont block on
+ * readpage (we've kicked readahead so there
+ * will be asynchronous progress):
+ */
+ if (flags & SPLICE_F_NONBLOCK)
+ break;
+
+ /*
+ * page didn't exist, allocate one
+ */
+ page = page_cache_alloc_cold(mapping);
+ if (!page)
+ break;
+
+ error = add_to_page_cache_lru(page, mapping, index,
+ mapping_gfp_mask(mapping));
+ if (unlikely(error)) {
+ page_cache_release(page);
+ break;
+ }
- if (PageUptodate(page))
- unlock_page(page);
- else {
- int error = mapping->a_ops->readpage(in, page);
+ goto readpage;
+ }
+
+ /*
+ * If the page isn't uptodate, we may need to start io on it
+ */
+ if (!PageUptodate(page)) {
+ lock_page(page);
+
+ /*
+ * page was truncated, stop here. if this isn't the
+ * first page, we'll just complete what we already
+ * added
+ */
+ if (!page->mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ break;
+ }
+ /*
+ * page was already under io and is now done, great
+ */
+ if (PageUptodate(page)) {
+ unlock_page(page);
+ goto fill_it;
+ }
+
+readpage:
+ /*
+ * need to read in the page
+ */
+ error = mapping->a_ops->readpage(in, page);
if (unlikely(error)) {
page_cache_release(page);
+ if (error == AOP_TRUNCATED_PAGE)
+ goto find_page;
break;
}
}
+fill_it:
pages[i] = page;
}
if (i)
return move_to_pipe(pipe, pages, i, offset, len, flags);
- return 0;
+ return error;
}
/**