From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f42.google.com (mail-pa0-f42.google.com [209.85.220.42]) by kanga.kvack.org (Postfix) with ESMTP id B93136B0071 for ; Tue, 9 Dec 2014 20:46:43 -0500 (EST) Received: by mail-pa0-f42.google.com with SMTP id et14so1756199pad.1 for ; Tue, 09 Dec 2014 17:46:43 -0800 (PST) Received: from mail-pa0-f42.google.com (mail-pa0-f42.google.com. [209.85.220.42]) by mx.google.com with ESMTPS id zv7si4533720pac.17.2014.12.09.17.46.41 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 09 Dec 2014 17:46:42 -0800 (PST) Received: by mail-pa0-f42.google.com with SMTP id et14so1739013pad.15 for ; Tue, 09 Dec 2014 17:46:41 -0800 (PST) From: Omar Sandoval Subject: [RFC PATCH v3 3/7] swap: use direct I/O for SWP_FILE swap_readpage Date: Tue, 9 Dec 2014 17:45:44 -0800 Message-Id: <9c1d4746d1e7e41114496be8912cb74e36d5df48.1418173063.git.osandov@osandov.com> In-Reply-To: References: In-Reply-To: References: Sender: owner-linux-mm@kvack.org List-ID: To: Alexander Viro , Andrew Morton , Chris Mason , Josef Bacik , Trond Myklebust , Christoph Hellwig , David Sterba , linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Omar Sandoval , Mel Gorman On Mon, Nov 17, 2014 at 07:48:17AM -0800, Christoph Hellwig wrote: > With the new iov_iter infrastructure that supprots direct I/O to kernel > pages please get rid of the ->readpage hack first. I'm still utterly > disapoined that this crap ever got merged. Cc: Mel Gorman Signed-off-by: Omar Sandoval --- mm/page_io.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/mm/page_io.c b/mm/page_io.c index 955db8b..10715e0 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -283,8 +283,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, set_page_writeback(page); unlock_page(page); - ret = mapping->a_ops->direct_IO(ITER_BVEC | WRITE, - &kiocb, &from, + ret = mapping->a_ops->direct_IO(WRITE, &kiocb, &from, kiocb.ki_pos); if (ret == PAGE_SIZE) { count_vm_event(PSWPOUT); @@ -348,12 +347,37 @@ int swap_readpage(struct page *page) } if (sis->flags & SWP_FILE) { + struct kiocb kiocb; struct file *swap_file = sis->swap_file; struct address_space *mapping = swap_file->f_mapping; + struct bio_vec bv = { + .bv_page = page, + .bv_len = PAGE_SIZE, + .bv_offset = 0, + }; + struct iov_iter to = { + .type = ITER_BVEC | READ, + .count = PAGE_SIZE, + .iov_offset = 0, + .nr_segs = 1, + }; + to.bvec = &bv; /* older gcc versions are broken */ + + init_sync_kiocb(&kiocb, swap_file); + kiocb.ki_pos = page_file_offset(page); + kiocb.ki_nbytes = PAGE_SIZE; - ret = mapping->a_ops->readpage(swap_file, page); - if (!ret) + ret = mapping->a_ops->direct_IO(READ, &kiocb, &to, + kiocb.ki_pos); + if (ret == PAGE_SIZE) { + SetPageUptodate(page); count_vm_event(PSWPIN); + ret = 0; + } else { + ClearPageUptodate(page); + SetPageError(page); + } + unlock_page(page); return ret; } -- 2.1.3 -- 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