mkfs: enable new features by default

Since the LTS is coming up, enable parent pointers and exchange-range by
default for all users.  Also fix up an out of date comment.

I created a really stupid benchmarking script that does:

#!/bin/bash

# pptr overhead benchmark

umount /opt /mnt
rmmod xfs
for i in 1 0; do
	umount /opt
	mkfs.xfs -f /dev/sdb -n parent=$i | grep -i parent=
	mount /dev/sdb /opt
	mkdir -p /opt/foo
	for ((i=0;i<5;i++)); do
		time fsstress -n 100000 -p 4 -z -f creat=1 -d /opt/foo -s 1
	done
done

This is the result of creating an enormous number of empty files in a
single directory:

# ./dumb.sh
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
real    0m18.807s
user    0m2.169s
sys     0m54.013s

naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=1
real    0m20.654s
user    0m2.374s
sys     1m4.441s

As you can see, there's a 10% increase in runtime here.  If I make the
workload a bit more representative by changing the -f argument to
include a directory tree workout:

-f creat=1,mkdir=1,mknod=1,rmdir=1,unlink=1,link=1,rename=1

naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=1
real    0m12.742s
user    0m28.074s
sys     0m10.839s

naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
real    0m12.782s
user    0m28.892s
sys     0m8.897s

Almost no difference here.  If I then actually write to the regular
files by adding:

-f write=1

naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=1
real    0m16.668s
user    0m21.709s
sys     0m15.425s

naming   =version 2              bsize=4096   ascii-ci=0, ftype=1, parent=0
real    0m15.562s
user    0m21.740s
sys     0m12.927s

So that's about a 2% difference.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 8f5a6fa56764539c95cd2bd667598b4482fae182..8db51217016eb056f9e2324b5ccf749e2d7249dc 100644 (file)
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -1044,7 +1044,7 @@ struct sb_feat_args {
        bool    inode_align;            /* XFS_SB_VERSION_ALIGNBIT */
        bool    nci;                    /* XFS_SB_VERSION_BORGBIT */
        bool    lazy_sb_counters;       /* XFS_SB_VERSION2_LAZYSBCOUNTBIT */
-       bool    parent_pointers;        /* XFS_SB_VERSION2_PARENTBIT */
+       bool    parent_pointers;        /* XFS_SB_FEAT_INCOMPAT_PARENT */
        bool    projid32bit;            /* XFS_SB_VERSION2_PROJID32BIT */
        bool    crcs_enabled;           /* XFS_SB_VERSION2_CRCBIT */
        bool    dirftype;               /* XFS_SB_VERSION2_FTYPE */
@@ -5984,11 +5984,12 @@ main(
                        .rmapbt = true,
                        .reflink = true,
                        .inobtcnt = true,
-                       .parent_pointers = false,
+                       .parent_pointers = true,
                        .nodalign = false,
                        .nortalign = false,
                        .bigtime = true,
                        .nrext64 = true,
+                       .exchrange = true,
                        /*
                         * When we decide to enable a new feature by default,
                         * please remember to update the mkfs conf files.