Hello !

I'am relative new to sybase and working with a performance problem on ASE 11.0.3 (....quite old release I have heard), I have been told that it is probably a spinlock-contention problem. I have read about spinlocks and it says that it has to with different "engines competing" for getting access to the cache (caches) but on this machine we only have one CPU and thus only one engine (Engine 0 in sp_sysmon output). In the same sp_sysmon output indeed I can see a very high spinlock contention (500 - 800 %) which I found confusing and I begin to suspect that report showing something wrong or could it be contention among threads.

When we have performance problem the CPU Utilization kernel part goes up to 90 - 95 % and truss shows that it deals a lot with poll() and kaio(). Sp_lock also shows that there is a lot of locking activity going on but no waits are registered in sp_sysmon report (..I'am used to Oracle where study waits is key issue when dealing with performance)