Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932939AbcJNR1E (ORCPT ); Fri, 14 Oct 2016 13:27:04 -0400 Received: from g2t1383g.austin.hpe.com ([15.233.16.89]:19093 "EHLO g2t1383g.austin.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932886AbcJNR0z (ORCPT ); Fri, 14 Oct 2016 13:26:55 -0400 From: Toshi Kani To: akpm@linux-foundation.org, dan.j.williams@intel.com Cc: viro@zeniv.linux.org.uk, ross.zwisler@linux.intel.com, linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Toshi Kani Subject: [PATCH] DAX: enable iostat for read/write Date: Fri, 14 Oct 2016 11:25:13 -0600 Message-Id: <1476465913-25305-1-git-send-email-toshi.kani@hpe.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2626 Lines: 85 DAX IO path does not support iostat, but its metadata IO path does. Therefore, iostat shows metadata IO statistics only, which has been confusing to users. Add iostat support to the DAX read/write path. Note, iostat still does not support the DAX mmap path as it allows user applications to access directly. Signed-off-by: Toshi Kani Cc: Andrew Morton Cc: Alexander Viro Cc: Dan Williams Cc: Ross Zwisler --- fs/dax.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/fs/dax.c b/fs/dax.c index 014defd..3aaaac2 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -144,6 +144,34 @@ static sector_t to_sector(const struct buffer_head *bh, return sector; } +static void dax_iostat_start(struct gendisk *disk, struct iov_iter *iter, + unsigned long *start) +{ + int rw = iov_iter_rw(iter); + int sec = iov_iter_count(iter) >> 9; + int cpu = part_stat_lock(); + + *start = jiffies; + part_round_stats(cpu, &disk->part0); + part_stat_inc(cpu, &disk->part0, ios[rw]); + part_stat_add(cpu, &disk->part0, sectors[rw], sec); + part_inc_in_flight(&disk->part0, rw); + part_stat_unlock(); +} + +static void dax_iostat_end(struct gendisk *disk, struct iov_iter *iter, + unsigned long start) +{ + unsigned long duration = jiffies - start; + int rw = iov_iter_rw(iter); + int cpu = part_stat_lock(); + + part_stat_add(cpu, &disk->part0, ticks[rw], duration); + part_round_stats(cpu, &disk->part0); + part_dec_in_flight(&disk->part0, rw); + part_stat_unlock(); +} + static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, loff_t start, loff_t end, get_block_t get_block, struct buffer_head *bh) @@ -265,9 +293,12 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, ssize_t retval = -EINVAL; loff_t pos = iocb->ki_pos; loff_t end = pos + iov_iter_count(iter); + struct gendisk *disk; + unsigned long start = 0; memset(&bh, 0, sizeof(bh)); bh.b_bdev = inode->i_sb->s_bdev; + disk = bh.b_bdev->bd_disk; if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ) inode_lock(inode); @@ -276,8 +307,14 @@ ssize_t dax_do_io(struct kiocb *iocb, struct inode *inode, if (!(flags & DIO_SKIP_DIO_COUNT)) inode_dio_begin(inode); + if (blk_queue_io_stat(disk->queue)) + dax_iostat_start(disk, iter, &start); + retval = dax_io(inode, iter, pos, end, get_block, &bh); + if (start) + dax_iostat_end(disk, iter, start); + if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ) inode_unlock(inode);