“Log Semaphore Requests” reports of contention for the log semaphore that protects the current page of the transaction log in cache. This data is meaningful for SMP environments only.
This category provides the following information:
Granted – The number of times a task was granted a log semaphore immediately after it requested one. “% of total” reports the percentage of immediately granted requests as a percentage of the total number of log semaphore requests.
Waited – The number of times two tasks tried to flush ULC pages to the log simultaneously and one task had to wait for the log semaphore. “% of total” reports the percentage of tasks that had to wait for a log semaphore as a percentage of the total number of log semaphore requests.
Total Log Semaphore Requests – The total number of times tasks requested a log semaphore including those granted immediately and those for which the task had to wait.