On Thu, 2017-01-12 at 10:02 -0800, Joe Perches wrote: > On Thu, 2017-01-12 at 11:38 -0700, Toshi Kani wrote: > > 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. > > [] > > diff --git a/fs/dax.c b/fs/dax.c > > [] > > @@ -1058,12 +1058,24 @@ dax_iomap_rw(struct kiocb *iocb, struct > > iov_iter *iter, > > { > > struct address_space *mapping = iocb->ki_filp->f_mapping; > > struct inode *inode = mapping->host; > > + struct gendisk *disk = inode->i_sb->s_bdev->bd_disk; > > loff_t pos = iocb->ki_pos, ret = 0, done = 0; > > unsigned flags = 0; > > + unsigned long start = 0; > > + int do_acct = blk_queue_io_stat(disk->queue); > > > > if (iov_iter_rw(iter) == WRITE) > > flags |= IOMAP_WRITE; > > > > + if (do_acct) { > > + sector_t sec = iov_iter_count(iter) >> 9; > > + > > + start = jiffies; > > + generic_start_io_acct(iov_iter_rw(iter), > > + min_t(unsigned long, 1, > > sec), > > I believe I mislead you with a thinko. > > Your original code was > (!sec) ? 1 : sec > and I suggested incorrectly using min_t > > It should of course be max_t. Sorry. My bad. I should have caught it. > Also, as sec is now sector_t (u64), perhaps this > unsigned long cast is incorrect. I see. Since iov_iter_count() returns a size_t value, I will use 'size_t' for 'sec' as you originally suggested. Thanks, -Toshi ��.n��������+%������w��{.n�����{���)��jg��������ݢj����G�������j:+v���w�m������w�������h�����٥