If either of these values is higher than approximately 20%, and size of your ULC is more than 2048, consider reducing the ULC size.
Check sections of your sp_sysmon report that relate to log activity:
Contention for semaphore on the user log caches (SMP only); see “ULC semaphore requests”
Contention for the log semaphore. (SMP only); see “Log semaphore requests”
The number of transaction log writes; see “Transaction log writes”
