Next step in the vectorisation process is the directory free block
encode/decode operations. There are relatively few of these, though
there are quite a number of calls to them.
Binary sizes:
text data bss dec hex filename
794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig
792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1
792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2
789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3
789005 96802 1096 886903 d8997 fs/xfs/xfs.o.p4
789061 96802 1096 886959 d88af fs/xfs/xfs.o.p5
789733 96802 1096 887631 d8b4f fs/xfs/xfs.o.p6
791421 96802 1096 889319 d91e7 fs/xfs/xfs.o.p7
791701 96802 1096 889599 d92ff fs/xfs/xfs.o.p8
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Conversion from on-disk structures to in-core header structures
currently relies on magic number checks. If the magic number is
wrong, but one of the supported values, we do the wrong thing with
the encode/decode operation. Split these functions so that there are
discrete operations for the specific directory format we are
handling.
In doing this, move all the header encode/decode functions to
xfs_da_format.c as they are directly manipulating the on-disk
format. It should be noted that all the growth in binary size is
from xfs_da_format.c - the rest of the code actaully shrinks.
text data bss dec hex filename
794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig
792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1
792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2
789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3
789005 96802 1096 886903 d8997 fs/xfs/xfs.o.p4
789061 96802 1096 886959 d88af fs/xfs/xfs.o.p5
789733 96802 1096 887631 d8b4f fs/xfs/xfs.o.p6
791421 96802 1096 889319 d91e7 fs/xfs/xfs.o.p7
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
The remaining non-vectorised code for the directory structure is the
node format blocks. This is shared with the attribute tree, and so
is slightly more complex to vectorise.
Introduce a "non-directory" directory ops structure that is attached
to all non-directory inodes so that attribute operations can be
vectorised for all inodes.
Once we do this, we can vectorise all the da btree operations.
Because this patch adds more infrastructure than it removes the
binary size does not decrease:
text data bss dec hex filename
794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig
792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1
792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2
789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3
789005 96802 1096 886903 d8997 fs/xfs/xfs.o.p4
789061 96802 1096 886959 d88af fs/xfs/xfs.o.p5
789733 96802 1096 887631 d8b4f fs/xfs/xfs.o.p6
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Next step in the vectorisation process is the leaf block
encode/decode operations. Most of the operations on leaves are
handled by the data block vectors, so there are relatively few of
them here.
Because of all the shuffling of code and having to pass more state
to some functions, this patch doesn't directly reduce the size of
the binary. It does open up many more opportunities for factoring
and optimisation, however.
text data bss dec hex filename
794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig
792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1
792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2
789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3
789005 96802 1096 886903 d8997 fs/xfs/xfs.o.p4
789061 96802 1096 886959 d88af fs/xfs/xfs.o.p5
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
Convert the rest of the directory data block encode/decode
operations to vector format.
This further reduces the size of the built binary:
text data bss dec hex filename
794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig
792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1
792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2
789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3
789005 96802 1096 886903 d8997 fs/xfs/xfs.o.p4
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
Following from the initial patches to vectorise the shortform
directory encode/decode operations, convert half the data block
operations to use the vector. The rest will be done in a second
patch.
This further reduces the size of the built binary:
text data bss dec hex filename
794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig
792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1
792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2
789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
Following from the initial patch to introduce the directory
operations vector, convert the rest of the shortform directory
operations to use vectored ops rather than superblock feature
checks. This further reduces the size of the built binary:
text data bss dec hex filename
794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig
792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1
792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
Lots of the dir code now goes through switches to determine what is
the correct on-disk format to parse. It generally involves a
"xfs_sbversion_hasfoo" check, deferencing the superblock version and
feature fields and hence touching several cache lines per operation
in the process. Some operations do multiple checks because they nest
conditional operations and they don't pass the information in a
direct fashion between each other.
Hence, add an ops vector to the xfs_inode structure that is
configured when the inode is initialised to point to all the correct
decode and encoding operations. This will significantly reduce the
branchiness and cacheline footprint of the directory object decoding
and encoding.
This is the first patch in a series of conversion patches. It will
introduce the ops structure, the setup of it and add the first
operation to the vector. Subsequent patches will convert directory
ops one at a time to keep the changes simple and obvious.
Just this patch shows the benefit of such an approach on code size.
Just converting the two shortform dir operations as this patch does
decreases the built binary size by ~1500 bytes:
$ size fs/xfs/xfs.o.orig fs/xfs/xfs.o.p1
text data bss dec hex filename
794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig
792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1
$
That's a significant decrease in the instruction cache footprint of
the directory code for such a simple change, and indicates that this
approach is definitely worth pursuing further.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
The on-disk format definitions for the directory and attribute
structures are spread across 3 header files right now, only one of
which is dedicated to defining on-disk structures and their
manipulation (xfs_dir2_format.h). Pull all the format definitions
into a single header file - xfs_da_format.h - and switch all the
code over to point at that.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
