A DESCRIPTION OF THE PROBLEM :
I'm running java in a docker container on a machine with 32 cores and 120GB ram. If I specify the heap size with Xmx, I can make use of all of that ram. If I specify it with -XX:+UseContainerSupport and -XX:MaxRAMPercentage, I get a MaxHeapSize of at most 32178700288, no matter the parameters I pass to java or docker. I can easily restrict the heap size to *below* 32178700288, but it refuses to ever to above.

As we can see from the output of these commands, anything where the target heap size would be above 32178700288 hit the limit.

$ docker run -it --rm -m 96g openjdk:11 java -XX:MaxRAMPercentage=95 -XX:+PrintFlagsFinal -XX:+UnlockExperimentalVMOptions +XX:+UseContainerSupport  -version | grep MaxHeapSize
   size_t MaxHeapSize                              = 32178700288                               {product} {ergonomic}

$ docker run -it --rm -m 16g openjdk:11 java -XX:MaxRAMPercentage=95 -XX:+PrintFlagsFinal -XX:+UnlockExperimentalVMOptions +XX:+UseContainerSupport  -version | grep MaxHeapSize
   size_t MaxHeapSize                              = 16322134016                               {product} {ergonomic}

$ docker run -it --rm -m 96g openjdk:11 java -XX:MaxRAMPercentage=50 -XX:+PrintFlagsFinal -XX:+UnlockExperimentalVMOptions +XX:+UseContainerSupport  -version | grep MaxHeapSize
   size_t MaxHeapSize                              = 32178700288                               {product} {ergonomic}

$ docker run -it --rm -m 16g openjdk:11 java -XX:MaxRAMPercentage=50 -XX:+PrintFlagsFinal -XX:+UnlockExperimentalVMOptions +XX:+UseContainerSupport  -version | grep MaxHeapSize
   size_t MaxHeapSize                              = 8589934592                                {product} {ergonomic}


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
* Create a docker machine with a lot of ram (for my tests, it was a n1-standard-32 in gloud
* Run: docker run -it --rm -m 96g openjdk:11 java -XX:MaxRAMPercentage=95 -XX:+PrintFlagsFinal -XX:+UnlockExperimentalVMOptions +XX:+UseContainerSupport  -version  | grep MaxHeapSize
* Value shows: 32178700288                               

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Value should show a value that is much larger, presumably 95% of 96gb, minus any other reserved thing.
ACTUAL -
32178700288 bytes                              

---------- BEGIN SOURCE ----------
docker run -it --rm -m 96g openjdk:11 java -XX:MaxRAMPercentage=95 -XX:+PrintFlagsFinal -XX:+UnlockExperimentalVMOptions +XX:+UseContainerSupport  -version  | grep MaxHeapSize
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
 docker run -it --rm -m 96g openjdk:11 java -XX:+PrintFlagsFinal -Xmx90G -XX:-UseContainerSupport -version  | grep MaxHeapSize
   size_t MaxHeapSize                              = 96636764160                               {product} {command line}