On Thu, 31 Jan 2013 22:49:50 +0100 Jan Kara <jack@xxxxxxx> wrote: > Add mapping lock to struct address_space and grab it in all paths > creating pages in page cache to read data into them. That means buffered > read, readahead, and page fault code. Boy, this does look expensive in both speed and space. As you pointed out in [0/n], it's 2-3%. As always with pagecache stuff, the cost of filling the page generally swamps any inefficiencies in preparing that page. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>