Hi There,

We are using jemalloc 5.0.1 on our project, and found that the physical memory usage goes high every several (>10) hours. Here is the log I captured, more than 10GB physical memory were used during this time:

Allocated: 56763404160, active: 64958468096, metadata: 3267106432, resident: 70248562688, mapped: 70786420736, retained: 405324754944
Allocated: 56876350976, active: 65120444416, metadata: 3292205344, resident: 74587324416, mapped: 75117805568, retained: 405240102912
Allocated: 56737409856, active: 64979918848, metadata: 3293146528, resident: 75795795968, mapped: 76325535744, retained: 404032372736
Allocated: 56738962464, active: 64995016704, metadata: 3296629168, resident: 76685611008, mapped: 77218127872, retained: 403615834112
Allocated: 56968671360, active: 65284304896, metadata: 3296170416, resident: 78292492288, mapped: 78825009152, retained: 402008952832
Allocated: 56968786248, active: 65279537152, metadata: 3298034096, resident: 79658573824, mapped: 80191090688, retained: 400642871296
Allocated: 56941156840, active: 65251299328, metadata: 3297322160, resident: 80860139520, mapped: 81392623616, retained: 399441338368
Allocated: 56991072392, active: 65310920704, metadata: 3312494544, resident: 82332794880, mapped: 82864013312, retained: 399729459200
Allocated: 57126460528, active: 65457401856, metadata: 3318715504, resident: 83553558528, mapped: 84290650112, retained: 399185723392
Allocated: 56571929400, active: 64856027136, metadata: 3341452928, resident: 85106311168, mapped: 85832876032, retained: 400474652672
Allocated: 56948892104, active: 65236578304, metadata: 3443298560, resident: 84992585728, mapped: 85696909312, retained: 413038342144

Except resident/mapped varies a lot, the others almost remains the same. What's the reason of this high physical memory usage? Does jemalloc reclaim the unused physical memory instantly or periodically? btw, Huge TLB is disabled on this machine.