User_reserve_hint_pct - does it affect kernel memory size

Hello,

I know there were many questions regarding ARC cache tuning but I could not find my specific case explain well.

We use couple large Sparc domains which have 1TB RAM (957GB exactly). They initially came with user_reserve_hint_pct set to 80%.

After deploying multiple databases on it we approach upper limit of user memory, but kernel and ARC cache still large. For example:

Page Summary                            Pages             Bytes  %Tot---------------------------- ----------------  ----------------  ----Kernel                               12153919             92.7G   10%Defdump prealloc                      1365671             10.4G    1%ZFS                                   5960702             45.4G    5%Anon                                 28671165            218.7G   23%Exec and libs                          667099              5.0G    1%Page cache                            5639876             43.0G    4%OSM                                  64686592            493.5G   52%Free (cachelist)                      1524977             11.6G    1%Free (freelist)                       4765903             36.3G    4%Total                               125435904              957G

On different domain we have changed hint to 85% and also removed deferred dump With roughly similar memory allocation we get significantly much smaller kernel and larger ARC cache.