The test is done to gauge the performance of SSD as a temporary solution to act as tmpdir for MySQL server where result set temporary files are heavily created.
Here is the test results:
Overall, ext2 yields much better results on random IO along with sequential read. All file systems are mounted with noatime and XFS is mounted with noatime + nobarrier
So, even if one decides to use SSD as MySQL data storage; it will be nice to avoid it for any log storage (error log, slow and general query logs, bin-logs and innodb transaction log) due to slower sequential writes. Sequential write on ext2 with O_DIRECT seems to be better than any other file system.