On Fri, Sep 08, 2023 at 12:27:57PM +1000, Paul Ripke wrote: > I need to read more code to see when the pools decide to release idle > pages - because this is remarkably wasteful considering my machine is > also paging, and "only" has 16GiB RAM. > > Memory resource pool statistics > Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg > Idle > buf2k 2048 830780 0 617706 207284 85623 121661 172466 0 inf > 6948 > vcachepl 640 44075984 0 43266390 5228141 5012754 215387 704585 0 inf > 3547 > pcgnormal 320 23415927 32666190 23388721 1050250 1045247 5003 89205 0 inf > 2425 > ffsdino2 264 43386098 0 42621716 1690136 1577576 112560 281810 0 inf > 2185 > ffsino 280 43312409 0 42548027 1850682 1733882 116800 301939 0 inf > 2143 > ractx 40 6888877 0 6846710 41237 37592 3645 4679 0 inf > 1780 > bufpl 280 557611 0 239663 31776 559 31217 31296 0 inf > 1362 > buf16k 16896 431232 0 350158 52798 21935 30863 32706 0 inf > 942 > mclpl 2048 120600 0 119876 32540 31337 1203 5270 0 261333 > 841 > pvpage 4096 61134 3 53585 40271 32334 7937 12454 0 inf > 388 > mbpl 520 205550 0 204337 13673 12993 680 3049 0 inf > 362 > pcglarge 1088 844473 0 825312 88124 81378 6746 9809 0 inf > 359 > buf4k 4096 28406 0 25833 5510 2654 2856 4001 0 inf > 283 > ... > Totals 1937415183 32666228 1927493251 11060670 10142826 917844 > > In use 3585418K, total allocated 5569236K; utilization 64.4%
The targets are roughly 10% of RAM for vnodes and 15% for bufcache which adds up to 25%. So this doesn't seem so totally off the mark. DIAGNOSTIC does add a bit of overhead since it messes up all the kmem cache sizes with debugging stuff. I have plans to reduce the overhead from vnodes but not enough to claw back 100s of MB.. Sometimes I think the method for sizing these caches should be non-linear or something - don't have a good idea yet. Andrew
