Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1501108

[PATCH] DAX: enable iostat for read/write

Show all headers | View raw

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 <toshi.kani@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
---
 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);
 

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

[PATCH] DAX: enable iostat for read/write Toshi Kani <toshi.kani@hpe.com> - 2016-10-14 19:30 +0200
  Re: [PATCH] DAX: enable iostat for read/write Dan Williams <dan.j.williams@intel.com> - 2016-10-14 19:40 +0200
    Re: [PATCH] DAX: enable iostat for read/write "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-10-14 20:50 +0200
  Re: [PATCH] DAX: enable iostat for read/write Dave Chinner <david@fromorbit.com> - 2016-10-15 10:00 +0200
    Re: [PATCH] DAX: enable iostat for read/write "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-10-17 20:00 +0200
      Re: [PATCH] DAX: enable iostat for read/write Dan Williams <dan.j.williams@intel.com> - 2016-10-17 21:00 +0200
        Re: [PATCH] DAX: enable iostat for read/write "Kani, Toshimitsu" <toshi.kani@hpe.com> - 2016-10-17 21:30 +0200

csiph-web