Re: xfs/599 on LBS

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Nov 01, 2023 at 05:36:13PM -0700, Luis Chamberlain wrote:
> xfs/599 takes a long time on LBS, but it passes. The amount of time it
> takes, however, begs the question if the test is could be trimmed to
> do less work because the larger the block size the larger the number of
> dirents and xattrs are used to create. The large dirents are not a
> problem. The amount of time it takes to create xattrs with hashcol however
> grows exponentially in time.
> 
> n=16k   takes 5   seconds
> n=32k   takes 30  seconds
> n=64k     takes 6-7 minutes
> n=1048576 takes 30 hours
> 
> n=1048576 is what we use for block size 32k.
> 
> Do we really need so many xattrs for larger block sizes for this test?

No, we don't.  The goal of this test is to create a two-level dabtree of
xattrs having identical hashes.  However, the test author apparently
forgot that if a dabtree is created in the attr fork, there will be a
dabtree entry for each extended attribute, not each attr leaf block.
Hence it's a waste of time to multiply da_records_per_block by
attr_records_per_block.

Patches soon, once I run this through overnight testing.

--D

> S1="KNR4qb1wJE1ncgC83X2XQg7CKwuqEYQjwuX3MG1o6FyqwrCXagIYlgGqtbLlpUn9prWpkCo9ChrxJOINgc3MBSG0La6Qhm9imcduPeGtC3IvQOzuKPsQAN3O5lVS9zha1giONke1RfnTcidsDlIxNcupydmZrdJmwHU7HRxWWqLTenWh3Gi5YNWExX0Ft94NEtfY8Lov2qvYJbTA5knONimQq5wUaK1Eo449pDXTnCOTRRhPnSHMXzNqT"
> 
> mkfs.xfs -f -b size=32k -s size=4k /dev/loop16
> mount /dev/loop16 /mnt
> touch /mnt/foo
> time xfs_db -r -c "hashcoll -a -n 1048576 -p /mnt/foo $S1" /dev/loop16 
> 
> But also, for the life of me, I can't get the btree printed out, I see
> the nvlist but not btree, you can print *everything* out with just
> -c 'print':
> 
> xfs_db -c 'path /hah' -c 'ablock 0' -c 'addr btree[0].before' -c 'print' /dev/loop16
> 
>   Luis
>