From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Yu Subject: [PATCH 5/7] f2fs: enhance multithread dio write performance Date: Fri, 11 Sep 2015 14:41:53 +0800 Message-ID: <000001d0ec5d$0bbd1880$23374980$@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1ZaI2o-0002qU-3Z for linux-f2fs-devel@lists.sourceforge.net; Fri, 11 Sep 2015 06:42:46 +0000 Received: from mailout1.samsung.com ([203.254.224.24]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1ZaI2m-0004a8-GP for linux-f2fs-devel@lists.sourceforge.net; Fri, 11 Sep 2015 06:42:46 +0000 Received: from epcpsbgm2new.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NUI00YLK2N0WI10@mailout1.samsung.com> for linux-f2fs-devel@lists.sourceforge.net; Fri, 11 Sep 2015 15:42:36 +0900 (KST) Content-language: zh-cn List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Jaegeuk Kim Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net When dio writes perform concurrently, our performace will be low because of Thread A's allocation of multi continuous blocks will be break by Thread B, there are two cases as below: - In Thread B, we may change current segment to a new segment for LFS allocation if we dio write in the beginning of the file. - In Thread B, we may allocate blocks in the middle of Thread A's allocation, which make blocks which allocated in Thread A being discontinuous. This patch adds writepages mutex lock to make block allocation in dio write atomic to avoid above issues. Test environment: ubuntu os with linux kernel 4.2+, intel i7-3770, 16g memory, 32g kingston sd card. fio --name seqw --ioengine=sync --invalidate=1 --rw=write --directory=/mnt/f2fs --filesize=256m --size=16m --bs=2m --direct=1 --numjobs=10 before: WRITE: io=163840KB, aggrb=3145KB/s, minb=314KB/s, maxb=411KB/s, mint=39836msec, maxt=52083msec patched: WRITE: io=163840KB, aggrb=10033KB/s, minb=1003KB/s, maxb=1124KB/s, mint=14565msec, maxt=16329msec Signed-off-by: Chao Yu --- fs/f2fs/data.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index a737ca5..a0a5849 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1536,7 +1536,9 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); size_t count = iov_iter_count(iter); + int rw = iov_iter_rw(iter); int err; /* we don't need to use inline_data strictly */ @@ -1555,12 +1557,17 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); - if (iov_iter_rw(iter) == WRITE) + if (rw == WRITE) { + mutex_lock(&sbi->writepages); __allocate_data_blocks(inode, offset, count); + } err = blockdev_direct_IO(iocb, inode, iter, offset, get_data_block_dio); - if (err < 0 && iov_iter_rw(iter) == WRITE) - f2fs_write_failed(mapping, offset + count); + if (rw == WRITE) { + mutex_unlock(&sbi->writepages); + if (err) + f2fs_write_failed(mapping, offset + count); + } trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err); -- 2.4.2 ------------------------------------------------------------------------------