XFS still gets dorked with?

Posted Jan 24, 2011 21:07 UTC (Mon) by dgc (subscriber, #6611)
In reply to: XFS still gets dorked with? by pr1268
Parent article: Kernel prepatch 2.6.38-rc2

Doesn't matter how long something has been around, it can still be improved. Code cleanups, shiny new go-fast features (e.g delayed logging), scalability improvements (e.g. lockless transaction reservation fast path), IO pattern improvements (e.g. optimised delayed writeback of metadata), etc are being made all the time.

Indeed, XFS has had a greater rate of code change that even btrfs since 2.6.32:

$ git diff --stat v2.6.32.. -- fs/xfs |tail -1
141 files changed, 14887 insertions(+), 16766 deletions(-)
$ git diff --stat v2.6.32.. -- fs/btrfs |tail -1
49 files changed, 13019 insertions(+), 5162 deletions(-)
$ git diff --stat v2.6.32.. -- fs/ext4 fs/jbd2 |tail -1
37 files changed, 6707 insertions(+), 3862 deletions(-)

By this metric, you could say that XFS is the most actively developed filesystem in Linux. :)

As a result, we do occasionally have a bug slip through the dev tree into a mainline tree, but that's why we have the -next tree and a series of -rc releases. The wider developer and tester commmunity will catch most problems like this before a full release is made. i.e. the process is working the way it should....

Cheers,

Dave.

XFS still gets dorked with?

Posted Jan 25, 2011 9:48 UTC (Tue) by dgm (subscriber, #49227) [Link] (2 responses)

Very nice to see XFS in good shape. But what I read in those statistics is slightly different.

Less lines were added to XFS than they were removed. That may mean code that's being heavily revisited, possible because it has languished somehow and is now being cleaned up?

Btrfs, on the other hand, adds far more lines that it removes, suggesting that its being developed and adding features at a fast pace. The difference in added lines between XFS and Btrfs is roughly 10%, not that much.

Finally, ext4 looks much more quiet. Adding features and fixing stuff here and there.

It would be nice to know the different sizes of each code base, but I assume they are comparable.

XFS still gets dorked with?

Posted Jan 25, 2011 12:09 UTC (Tue) by cesarb (subscriber, #6266) [Link]

> It would be nice to know the different sizes of each code base, but I assume they are comparable.

$ sloccount fs/xfs
[...]
SLOC Directory SLOC-by-Language (Sorted)
47802 top_dir ansic=47802
11840 linux-2.6 ansic=11840
4628 quota ansic=4628
145 support ansic=145

Totals grouped by language (dominant language first):
ansic: 64415 (100.00%)
[...]

$ sloccount fs/btrfs
[...]
SLOC Directory SLOC-by-Language (Sorted)
46176 btrfs ansic=46148,sh=28

Totals grouped by language (dominant language first):
ansic: 46148 (99.94%)
sh: 28 (0.06%)
[...]

$ sloccount fs/ext4 fs/jbd2
[...]
SLOC Directory SLOC-by-Language (Sorted)
24465 ext4 ansic=24465
4597 jbd2 ansic=4597

Totals grouped by language (dominant language first):
ansic: 29062 (100.00%)
[...]

XFS still gets dorked with?

Posted Jan 25, 2011 15:49 UTC (Tue) by bronson (subscriber, #4806) [Link]

> Less lines were added to XFS than removed. That may mean code that's being heavily revisited ... and is now being cleaned up?

Or it may indicate code that is so good and forward thinking that it was hoisted into the VFS layer. Dunno! It's a bad idea to read too much into statistics alone.